AN651

Silicon Laboratories

EVALUATION BOARD TEST PROCEDURE

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Rev. 0.5 7/18 Copyright © 2018 by Silicon Laboratories AN651 AN651 Si468 X E VALUATION B OARD TEST P ROCEDURE 1. Introduction The purpose of this document is to describe the test procedures us ed in Silicon Labora tories for the Si468x evaluation boards (EVB). It is also in tended to enable custom ers to exactly replicate Silicon Laboratories’ test environment so that variances in cu stomers’ and Silicon Lab oratories’ measured re sults can be accurately compared. This document covers FM, FMHD radio, and DAB/DAB+ radio tests for the Si468x receivers and FM HD demodulators. The pass/fail criteria for each test are provided in the respective data sheets. The Si468x evaluation boards and software provide a pl atform to program, test, and operate the Si468x devices. The system consists of two boards: a baseboard and an RF daughter card. The baseboard provides all necessary support functions, including a USB-based programming inte rface, audio output connecti on points and an optional external clock input. In addition, the baseboard prov ides a codec for converting analog audio output to I 2S digital output. The RF daughter card contains the receiver and connection points for RF input. Refe r to the EVB User’s Guides for detailed explanations of the EVB hardware an d software. Table 1 summarizes the functionality of each device in the family. Table 1. Product Family Function

Description

  Si4684 FM/FM RDS DAB/DAB+/   Si4688 FM/FM RDS HD-FM/DAB DAB+ Si4683 AM/HD-AM/FM/ Si4685 AM/FM/FM RDS/ Si4689 AM/HD-AM/FM/ FM RDS/HD-FM/ DAB/DAB+

Test Setup and Instrument Settings

Figure 1. Si468x Test Setup

4 Rev. 0.5 2. FM Analog Modulation in Stereo Mode a. Set Frequency = 98.1 MHz b. Set Level = 60 dBµV. c. Hit config button on Baseband block. d. Select FM_STEREO under Broadcast Standards i. Audio Settings 1. Deviation = 22.5 kHz 2. Audio Source = LF Generator 3. LF Generator Frequency = 1 kHz 4. Audio Mode = Left 5. Preemphasis = 75 µs ii. Stereo Pilot Tone Settings 1. Pilot State = ON 2. Pilot Deviation = 6.75 kHz iii. State = ON (This turns on modulation) iv. Close the config panel. e. Click on the ON check box in the RF/A Mod block to turn RF ON 3. FM Analog Modulation in Stereo Mode with RDS enabled a. Set Frequency = 98.1 MHz b. Set Level = 60 dBµV. c. Hit config button on Baseband block. d. Select FM_STEREO under Broadcast Standards i. Audio Settings 1. Deviation = 22.5 kHz 2. Audio Source = LF Generator 3. LF Generator Frequency = 1 kHz 4. Audio Mode = Left 5. Preemphasis = 75 µs ii. Stereo Pilot Tone Settings 1. Pilot State = ON 2. Pilot Deviation = 6.75 kHz iii. Click on RDS/RBDS Configurations 1. State = ON 2. Deviation = 2 kHz 3. Program Identification set to 0x0123 iv. State = ON (This turns on modulation) v. Close the config panel. e. Click on the ON check box in the RF/A Mod block to turn RF ON 4. FMHD Digital Modulation a. Set Frequency = 98.1 MHz b. Set Level = –47 dBm. c. Hit config button on Baseband block. d. Select ARB

Rev. 0.5 5 i. Click on Load Waveform ii. Select the test vector from the location on either SMBV hard drive or an external USB drive. iii. Hit Select iv. State = ON (This turns on modulation) v. Close the config panel. e. Click on the ON check box in the RF/A Mod block to turn RF ON 5. DAB Digital Modulation a. Set Frequency = 207.008 MHz b. Set Level = –47 dBm. c. Hit config button on Baseband block. d. Select ARB i. Click on Load Waveform ii. Select the test vector from the location on either SMBV hard drive or an external USB drive. iii. Hit Select iv. State = ON (This turns on modulation) v. Close the config panel. e. Click on the ON check box in the RF/A Mod block to turn RF ON. 6. AM Analog Modulation a. Set frequency = 1 MHz b. Set Level = 60 dBµV c. Hit config button on RF/A Mod block. i. Select AM Modulation under Analog Modulation. ii. Set AM Modulation Depth = 30%. iii. Set Source = LFGEN (internal). iv. Set LFGEN frequency = 1 kHz. d. Click on the ON check box in the RF/A Mod block to turn RF ON. 7. AMHD Modulation a. Set Frequency=1 MHz b. Set Level=60 dBuV c. Hit config button on Baseband block. d. Select ARB. i. Click on Load Waveform. ii. Select the test vector from the location on either SMBV hard drive or an external USB drive. iii. Hit Select. iv. State=ON. (This turns on modulation.) v. Close the config panel.

6 Rev. 0.5 2.2.2. SML Settings for FM Analog Test Cases 1. FM Analog Modulation in Mono Mode a. Set RF Frequency = 98.1 MHz b. Set RF Level = 60 dBµV c. Select FM Modulation. i. FM Source = LFGEN ii. FM Deviation = 22.5 kHz iii. LFGen Freq = 1 kHz d. Enable modulation. –MOD ON e. Enable carrier. –RF ON 2. FM Analog Modulation in Stereo Mode a. Set RF Frequency = 98.1 MHz b. Set RF Level = 60 dBµV c. Select Stereo Modulation i. Source = LFGEN ii. FM Deviation = 22.5 kHz iii. Mode = L = R iv. LFGen Freq = 1 kHz v. Preemphasis = 75 µs vi. Pilot State = ON vii.Pilot Deviation = 6.75 kHz d. Enable modulation. –MOD ON e. Enable carrier. –RF ON 3. FM Analog Modulation in Stereo Mode with RDS enabled a. Set RF Frequency = 98.1 MHz b. Set RF Level = 60 dBµV c. Select Stereo Modulation i. Source = LFGEN ii. FM Deviation = 22.5 kHz iii. Mode = L = R iv. LFGen Freq = 1 kHz v. Preemphasis = 75 µs vi. Pilot State = ON vii.Pilot Deviation = 6.75 kHz viii.Set RDS = ON ix. Set RDS Deviation = 2 kHz x. Set Program Identification set to 0x0123 xi. Set Traffic Announcement = OFF xii.Set Traffic Program = OFF. d. Enable modulation. –MOD ON e. Enable carrier. –RF ON 4. AM Analog Modulation a. Set RF Frequency = 1 MHz.

Rev. 0.5 7 b. Set RF Level = 60 dB μV. c. Select AM Modulation. i. Set AM Modulation Depth = 30%. ii. Set Source = LFGEN (internal). iii. Set LFGEN frequency = 1 kHz. d. Enable modulation. –MOD ON. e. Enable carrier. –RF ON.

equipment used for FM analog radio tests. Several issues must be considered to make accurate measurements. the Mini-Circuit power combiner is approximately 6 dB. signal generator to EMF, double the voltage (add 6 dB). Table 2. Si468x Analog FM Tuner Test Equipment *Note: You can power up the EVB through the USB port for these tests.

Set frequency = 98.1 MHz.
Tune the 46xx in tune mode = 0, FM analog mode.
Set mono = On. For mono only operation:
Set soft mute = Off. For soft mute off:

Table 3. FM Tuner Settings

10 Rev. 0.5 3.2. FM Analog Radio Test Procedures The following procedures measure analog audio output. 3.2.1. Sensitivity Sensitivity of a receiver is a measure of its ability to receive weak signals and produce an audio frequency output of usable magnitude and acceptable quality. Sensitiv ities may be defined with respect to many different characteristics of the output signal. For the purposes of ou r testing, sensitivity is the minimum RF level required to produce an audio output with a specified signal-to-noise and distortion ratio, 26 dB. Please note that the sensitivity measurement is defined wit h respect to SINAD and not SNR. Descrip tions for these two measurements will be given in the following sections. 1. Connect test equipment as shown in Figure 1. 2. Configure the tuner in standard configuration. 3. Configure the audio analyzer: f. Set Function = THD+N/SINAD. g. Set Measurement Mode = SINAD. h. Set Fundamental = 1000 Hz Fixed. i. Set Unit = dB. j. Set Filter = A-weighting. k. Set Frequency Limit Low = 300 Hz. l. Set Frequency Limit High = 15000 Hz. m. Set Function Settling = Off (for quick measurement) or Average (for accurate measurement). 4. Configure generator #1 in FM Analog Modulation in Mono mode as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 98.1 MHz. b. FM Deviation = 22.5 kHz. c. LFGEN frequency = 1 kHz. 5. Disable generator #2. 6. Adjust generator #1 RF level, V RF0, until audio analyzer SINAD = 26 dB. 7. Sensitivity (dBµV) = V RF0.

produce an inter-modulation product at the same sensitivity level. Figure 3. Graphical Representation of IP3

Connect test equipment as shown in Figure 1.
Make a sensitivity measurement, VRF
Configure the tuner in standard configuration, except fo r the AGC setting. For this section of the test, set AGC
Configure the audio analyzer:

b. Set Function = THD+N / SINAD. i. Set Measurement Mode = SINAD.

Configure generator #1 in FM Analog Modulation in mono mode as described in "2.2. Signal Generator

a. Carrier frequency = 106.1 MHz.

12 Rev. 0.5 6. Configure generator #2 in FM Analog Modulation in mono mode as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 102.1 MHz. b. RF level = 70 dBµV. c. Disable modulation. d. Enable carrier. 7. Simultaneously adjust the generator #1 and generator #2 RF level, VRF 1, until SINAD = 26 dB. 8. IP3 (dBµV) = VRF 1 + ½ (VRF1 –V R F0).

Rev. 0.5 13 3.2.3. Adjacent / Alternate Channel Rejection Rejection is a measure of the performance of a radio receiver to respond only to the tuned transmission (such as a radio station) and reject other signals nearby, such as another broadcast on an adjacent channel. The adjacent/ alternate channel rejection tests are performed at –200 and –400 kHz offsets. 1. Configure the tuner in standard configuration: a. Set Function = THD+N/SINAD. b. Set Measurement Mode = SINAD. c. Filter = A-weighting. d. Frequency Limit Low = 300 Hz. e. Frequency Limit High = 15000 Hz. f. Set Frequency Mode = FIX: 1 kHz. g. Function Setting = Off (for quick measurement) or Average (for accurate measurement). h. Select Unit = dB. 2. Configure generator #1 in FM Analog Modulation in mono mode as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 98.1 MHz. b. RF level VRF0 = 40 dBµV. c. FM Deviation = 22.5 kHz. d. LFGEN frequency = 1 kHz. 3. Configure generator #2 in FM Analog Modulation in mono mode as described in "2.2. Signal Generator Settings" on page 3 with the following settings: (alternate channel). b. FM Deviation = 22.5 kHz. c. LFGEN frequency = 0.4 kHz. 4. Adjust generator #2 RF level, VR F1, until the SINAD level is 26 dB. 5. Rejection (dB) = VRF1 – VRF0.

14 Rev. 0.5 3.2.4. AM Suppression AM suppression of an FM receiv er represents the ability of th e receiver to reject AM of the input signal. AM might be a result of fading multi-path signals, aircraft flutter, AM at the transmitter, and AM introduced in the receiver by pass-band limitations and mistuning. AM suppression is measured as a ratio of voltage measured with an FM modulated signal to that of an AM modulated signal. 1. Connect test equipment as shown in Figure 1. 2. Configure the tuner in standard configuration. 3. Configure the audio analyzer: a. Set Function = RMS Select. i. Set Bandwidth = BP 3%. ii. Set Units = dBV. iii. Set Frequency Mode = FIX: 1 kHz. 4. Configure generator #1 in FM Analog Modulation in mono mode as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 98.1 MHz. b. RF level = 60 dBµV. c. Select FM Modulation. d. FM Deviation = 22.5 kHz. e. LFGEN frequency = 1 kHz. 5. Record the audio level, VAUDIO 6. Turn off generator #1 FM modulation. 7. Configure generator #1: a. Carrier frequency = 98.1 MHz. b. RF level = 60 dBµV. c. Select AM Modulation. i. Set Depth = 30%. ii. Set Source = LFGEN. iii. Set LFGEN frequency = 1 kHz. d. Enable modulation. e. Enable carrier. 8. Record the audio level, VAUDIO 9. AM Suppression (dB) = VAUDIO 0 –V A U D I O1.

output voltage level is 3 dB below the value at a specified high RF input signal level). Figure 4. Image Frequency Spectrum

The image injection side can be positive or negative depending on the frequency of tuner. For the frequency

use positive or negative image offset.

Configure the audio analyzer:

a. Set Function = THD+N/SINAD. b. Set Measurement Mode = SINAD. d. Frequency Limit Low = 300 Hz. e. Frequency Limit High = 15000 Hz. f. Set Frequency Mode = FIX: 1 kHz. g. Function Setting = Off (for quick measurement) or Average (for accurate measurement).

Configure generator #1 in FM Analog Modulation in mono mode as described in "2.2. Signal Generator

a. Carrier frequency = 98.1 MHz.

Make a sensitivity measurement as described in "3.2.1. Sensitivity" on page 10 and save sensitivity level as
Set the RF level of generator#1 to VRF2 = VRF1 +3 dB

16 Rev. 0.5 6. Configure generator #2 in FM Analog Modulation in mono mode as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 97.823 MHz (image at 258 kHz)* b. FM Deviation = 22.5 kHz. c. LFGEN frequency = 400 Hz. 7. Set generator#2 initially at VRF2. Increase the RF level of the image (generator #2) until SINAD drops back to 26 dB. Call this RF level VRF3. 8. Image rejection (dB) = VRF3 – VRF2.

Rev. 0.5 17 3.2.6. RDS Sensitivity RDS sensitivity is the minimum RF level required to pr oduce an audio output with a specified Block Error Rate (BLER), 5%. BLER is a ratio of the number of data blocks received with at least one un-correctable bit to the number of blocks received. 1. Connect test equipment as shown in Figure 1. 2. Configure the tuner in standard configuration. 3. Set RDS ON. 4. Configure generator #1 in FM Analog Modulation in ster eo mode with RDS enabled as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 98.1 MHz. b. RF level = 4 µV (target sensitivity level). c. FM Deviation = 22.5 kHz. d. Mode = LEFT. e. LFGEN frequency = 1 kHz. f. Set Pre-emphasis = 75 µs. g. Pilot Deviation = 6.75 kHz. h. RDS Deviation = 2 kHz. i. RDS Data Set = 1. 5. Disable generator #2. 6. Adjust generator #1 RF level, V RF0, until BLER = 5%.* 7. Sensitivity (µV) = V RF0. *Note: Block Error Rate (BLER) measurement settles approximately in 20 seconds. Because the Silicon Laboratories auto- mated test system configures the generator after the tuner, the BLER reading should be allowed to update twice before it is considered valid. Alternatively, the tuner could be configured after th e generator and the BLER reading would be valid after one update.

18 Rev. 0.5 3.2.7. RDS BLER BLER stands for block error rate, which is a ratio of number of data blocks received with at least one un-correctable bit to the number of blocks received. This test is often used to test the RDS Sensitivity (BLER <5%) specification during production. 1. Connect test equipment as shown in Figure 1. 2. Configure the tuner in standard configuration. 3. Set RDS ON 4. Configure generator #1 in FM Analog Modulation in ster eo mode with RDS enabled as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 98.1 MHz. b. Set RF level = 7 µV (target RDS sensitivity level + 3 µV). c. FM Deviation = 22.5 kHz. d. Mode = LEFT. e. LFGEN frequency = 1 kHz. f. Pre-emphasis = 75 µs. g. Pilot Deviation = 6.75 kHz. h. RDS Deviation = 2 kHz. i. RDS Data Set = 1. 5. Read BLER * from the GUI after 22 seconds. *Note: Block Error Rate (BLER) measurement settles approxim ately in 20 seconds. Because the Silicon Laboratories automated test system configur es the generator after the tuner, the BLER reading should be allowed to update twice before it is considered valid. Alternatively, the tuner could be configured after the generator and the BLER reading would be valid after an update.

Rev. 0.5 19 3.2.8. RDS Persistence RDS Sync is influenced by the signal quality and streng th. Once the RDS is synchroni zed, the FM tuner has the ability to maintain its synchronization even with high BLER and fading signa l strength. This test measures the ability to maintain RDS Sync in degrading signal condition. 1. Connect test equipment as shown in Figure 1. 2. Configure the tuner in standard configuration. 3. Set RDS ON. 4. Configure generator #1 in FM Analog Modulation in ster eo mode with RDS enabled as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 98.1 MHz. b. RF level = 4 µV (RDS sensitivity level). c. FM Deviation = 22.5 kHz. d. Mode = LEFT. e. LFGEN frequency = 1 kHz. f. Pre-emphasis = 75 µs. g. Pilot Deviation = 6.75 kHz. h. RDS Deviation = 2 kHz. i. RDS Data Set = 1. 5. Slowly decrease the RF level until green "RDS" disp lay on the main window of the Si47xx GUI goes off. 6. Record the RF level and BLER after 22 seconds.

20 Rev. 0.5 3.2.9. THD Measurement The total harmonic distortion, or THD, is a measurement of the harmonic distortion present at the audio output and is defined as the ratio of the sum of the powers of all harmonic components calculated in RMS fashion to the power of the fundamental. 3.2.9.1. Mono THD Measurement 1. Connect test equipment as shown in Figure 1. 2. Configure the tuner in standard configuration. 3. Configure the audio analyzer: a. Set Function = THD. b. Set Measurement Mode = All di (all harmonics). c. Fundamental = 1000 Hz Fixed. d. Equalizer = Off. e. Function Settling = Off (for quick measuremen t) or Average (for accurate measurement). f. Select Unit = %. 4. Configure generator #1 in FM Analog Modulation in Mono mode as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 98.1 MHz. b. FM deviation = 75 kHz. c. RF level = 60 dBµV. d. LFGEN frequency = 1 kHz. 5. Disable generator #2. 6. Record THD (%).

Rev. 0.5 21 3.2.9.2. Stereo THD Measurement 1. Connect test equipment as shown in Figure 1. 2. Configure the tuner in stereo mode. 3. Configure the audio analyzer: a. Set Function = THD. b. Set Measurement Mode = All di (all harmonics). c. Fundamental = 1000 Hz Fixed. d. Equalizer = Off. e. Function Settling = Off (for quick measuremen t) or Average (for accurate measurement). f. Select Unit = %. 4. Configure generator #1 in FM Analog Modulation in Stereo mode as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 98.1 MHz. b. FM Deviation = 67.5 kHz. c. RF level = 60 dBµV. d. LFGEN frequency = 1 kHz. e. Pilot deviation = 6.75 kHz. f. Mode = Left. g. Preemphasis = 75 µs. 5. Disable generator #2. 6. Record THD (%).

22 Rev. 0.5 3.2.10. SNR The signal-to-noise ratio of a receiver, under specified conditions, is the ratio of the audio frequency output voltage due to the signal to that due to random noise. The noise may be measured using different filtering techniques. The technique used in this document is the A-weighting filter. We ighting filters are used to determine the loudness of sounds, particularly noise. A-weighting filter is commonly used to emphasize frequencies around 3–6 kHz, where the human ear is most sensitive, while attenuating very high and very low frequencies to which the ear is insensitive. The aim is to ensure that measured loudne ss corresponds well with subjectively perceived loudness. A-weighting is only really valid for relatively quiet sounds and for pure tones. 3.2.10.1. Mono SNR 1. Connect test equipment as shown in Figure 1. 2. Configure the tuner in standard configuration. 3. Configure the audio analyzer: a. Set Function = THD+N / SINAD. b. Set Measurement Mode = NOISE. c. Set Units = dB. d. Set Filter = A-weighting. e. Set Frequency Limit Low = 300 Hz. f. Set Frequency Limit Upper = 15000 Hz. g. Set Function Settling = Off (for quick measurement) or Average (for accurate measurement) 4. Configure generator #1 in FM Analog Modulation in mono mode as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 98.1 MHz. b. RF level = 60 dBµV. c. FM Deviation = 22.5 kHz. d. LFGEN frequency = 1 kHz. 5. Record SNR (d B) = Noise (dB)

Rev. 0.5 23 3.2.10.2. Stereo SNR 1. Connect test equipment as shown in Figure 1. 2. Configure the tuner in stereo mode. 3. Configure the audio analyzer: a. Set Function = THD+N / SINAD. b. Set Measurement Mode = NOISE. c. Set Units = dB d. Set Filter = A-weighting. e. Set Frequency Limit Low = 300 Hz. f. Set Frequency Limit Upper = 15000 Hz. g. Function Settling = Off (for quick measuremen t) or Average (for accurate measurement). 4. Configure generator #1 in FM Analog Modulation in stereo mode as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 98.1 MHz. b. FM Deviation = 67.5 kHz. c. RF level = 60 dBµV. d. LFGEN frequency = 1 kHz. e. Pilot deviation = 6.75 kHz. f. Mode = Left. g. Preemphasis = 75 µs. 5. Record SNR (dB) = Noise (dB).

24 Rev. 0.5 3.2.11. SINAD Signal to noise and distortion (SINAD) is similar to signal to noise ratio, but includes distortion and is a ratio of “signal plus noise plus distortion” to “noise plus distortion.” To make the SINAD measurement, a signal modulated with an audio tone is entered into the rece iver. A measurement of the whole signal, i.e., the signal plus noise plus distortion, is made by the audio analyzer. The audio tone is then removed by the analyzer and the remaining noise and distortion is measured. 3.2.11.1. Mono SINAD 1. Connect test equipment as shown in Figure 1. 2. Configure the tuner in standard configuration. 3. Configure the audio analyzer: a. Set Function = THD+N / SINAD. b. Set Measurement Mode = SINAD. c. Set Units = dB. d. Set Filter = A-weighting. e. Set Frequency Limit Low = 300 Hz. f. Set Frequency Limit Upper = 15000 Hz. g. Set Function Settling = Off (for quick measurement) or Average (for accurate measurement) 4. Configure generator #1 in FM Analog Modulation in mono mode as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 98.1 MHz. b. RF level = 60 dBµV. c. FM Deviation = 22.5 kHz. d. LFGEN frequency = 1 kHz. 5. Record SINAD (dB) = SINAD (dB).

Rev. 0.5 25 3.2.11.2. Stereo SINAD 1. Connect test equipment as shown in Figure 1. 2. Configure the tuner in stereo mode. 3. Configure the audio analyzer: a. Set Function = THD+N / SINAD. b. Set Measurement Mode = SINAD c. Set Units = dB. d. Set Filter = A-weighting. e. Set Frequency Limit Low = 300 Hz. f. Set Frequency Limit Upper = 15000 Hz. g. Set Function Settling = Off (for quick measurement) or Average (for accurate measurement) 4. Configure generator #1 in FM Analog Modulation in stereo mode as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 98.1 MHz. b. FM Deviation = 67.5 kHz. c. RF level = 60 dBµV. d. LFGEN frequency = 1 kHz. e. Pilot deviation = 6.75 kHz. f. Mode = Left. g. Preemphasis = 75 µs. 5. Record SINAD (dB) = SINAD (dB).

26 Rev. 0.5 3.2.12. Audio Output Voltage Higher audio output voltage is an indicator of cleaner sound from the tuner. It is measured as an RMS value under standard operating conditions. 1. Connect test equipment as shown in Figure 1. 2. Configure the tuner in standard configuration. 3. Configure the audio analyzer: a. Set Function = RMS Select. i. Set Bandwidth = BP 3%. ii. Set Units = V RMS. iii. Set Frequency Mode = FIX: 1 kHz. 4. Configure generator #1 in FM Analog Modulation in mono mode as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 98.1 MHz. b. RF level = 60 dBµV. c. FM Deviation = 22.5 kHz. d. LFGEN frequency = 1 kHz. 5. Audio level (V RMS) = VAUDIO0.

Rev. 0.5 27 3.2.13. Audio L/R Imbalance The level deviation between the two stereo channels is a quality criterion of the tuner because level differences shift the center for stereo sound impression. Audio L/R imbalance is the ratio of left to right channel output voltage. 1. Connect test equipment as shown in Figure 1. 2. Configure the tuner in standard configuration. 3. Configure the audio analyzer: a. Set Function = RMS Select. i. Set Bandwidth = BP 3%. ii. Set Units = dBV. iii. Set Frequency Mode = FIX: 1 kHz. 4. Configure generator #1 in FM Analog Modulation in mono mode as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 98.1 MHz. b. RF level = 60 dBµV. c. Set FM Deviation = 75 kHz. d. Set LFGEN frequency = 1 kHz. 5. Left channel audio level (dBV) = VAUDIO 6. Right channel audio level (dBV) = VAUDIOR. 7. Audio L/R imbalance (dB) = abs (VAUDIO L –V A U D I OR).

28 Rev. 0.5 3.2.14. Audio Band Limits/Audio Frequency Response The audio frequency response of a tuner is influenced by the quality of the IF section, detector, stereo coder and de-emphasis circuit. The emphasis of 75 µs specified by the standards for VHF FM transmissions is simulated in the signal generator. This means that low-frequency audio signals are modulated with a low deviation. The frequency deviation is then increased by emphasis to the maximum permissible deviation at the upper frequency limit. This effect is compensated by the de-emphasis circuit in the tuner so that the frequency response of the audio signal becomes as linear as possible. Audio frequency resp onse is the measure of linearity of output voltage vs. modulation frequency across the audio band. The frequency response of pre-emphasis has the effect of a 1st order highpass filter with predefined time constant, in this case 75 µs. Pre-emphasis with this time constant increases the signal by a factor of about 5.3 at 15 kHz relative to low frequencies. It is important to note that the maximum deviation of the system should not be exceeded even at high frequencies while pre-emphasis is on. Therefore, if measurem ents are performed at the modulation frequency with pre-emphasis on, the deviatio n should be adjusted so that the maximum permissible deviation is only attained at a modulation frequency of 15 kHz. In this case, the maximum deviation that can be adjusted for frequency response measurements is appr oximately 14%, 10.5 kHz. This influence must also be taken into account for measurements with the 1 kHz standar d test frequency. For 1 kHz test frequency, the setting is approximately 90% at 75 µs pre-emphasis. 1. Connect test equipment as shown in Figure 1. 2. Configure the tuner in standard configuration. 3. Configure the audio analyzer: a. Set Function = RMS Select. i. Set Bandwidth = BP 3%. ii. Set Units = dBV. iii. Set Frequency Mode = FIX: 1 kHz. 4. Configure generator #1 in FM Analog Modulation in stereo mode as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 98.1 MHz. b. RF level = 60 dBµV. c. FM Deviation = 10.5 kHz. d. Mode = L = R. e. LFGEN frequency = 1 kHz. f. Pre-emphasis = 75 µs. g. Pilot Deviation = 6.75 kHz. 5. Audio 1 kHz level (dBV) = V 1kHz. 6. Configure audio analyzer frequency mode through RMS Select Function.* Set Frequency Mode = FIX: 30 Hz. 7. Configure generator #1 LFGEN frequency = 30 Hz. 8. Audio 30 Hz level (dBV) = V 30Hz. 9. Configure audio analyzer frequency mode through RM S Select Function. Set Frequency Mode = FIX: 15 kHz. 10.Configure generator #1 LFGEN frequency = 15 kHz. 11.Audio 15 kHz level (dBV) = V 15kHz. 12.Audio frequency response (dB) equals the greater magnitude of (V 30Hz –V 1kHz) and (V15kHz –V 1kHz). *Note: R&S audio analyzer should be set to 22 kHz analyzer mode to select this frequency mode.

Rev. 0.5 29 3.2.15. Audio Stereo Separation Crosstalk occurs when signal components of a channel are coupled into another audio channel. This reduces channel separation and thus impairs the stereo effect. Au dio stereo separation is the level ratio of the wanted signal in a channel to the unwanted signal coupled into t he other channel. Only the left channel is modulated and the levels are measured in both channels to obtain th e ratio. To suppress the noise components, a selective measurement is carried out. 1. Connect test equipment as shown in Figure 1. 2. Configure the tuner in standard configuration, except fo r setting in mono operation. Set the tuner in stereo mode. 3. Configure the audio analyzer: a. Set Function = RMS Select. i. Set Bandwidth = BP 3%. ii. Set Units = dBV. iii. Set Frequency Mode = FIX: 1 kHz. 4. Configure generator #1 in FM Analog Modulation in stereo mode as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 98.1 MHz. b. RF level = 60 dBµV. c. FM Deviation = 67.5 kHz. d. Mode = Left. e. Set LFGEN frequency = 1 kHz. f. Pre-emphasis = 75 µs. g. Pilot Deviation = 6.75 kHz. 5. Left channel audio level (dBV) = VAUDIO 6. Right channel audio level (dBV) = VAUDIOR. 7. Audio Stereo Separation (dB) = abs (VAUDIO L –V A U D I OR).

30 Rev. 0.5 3.2.16. Stereo Pilot Rejection A pilot tone is transmitted at 19 kHz to identify stereo broadcast transmissions. In orde r not to disturb instruments such as amplifiers and recorders connected to the tuner, the pilot tone and its subcarriers must be sufficiently suppressed in the tuner. Stereo pilot rejection is the quality criterion of a tuner that is measured as the ratio of wanted audio frequency voltage to pilot frequency voltage according to the equation: Pilot Rejection = Vaudio0 (1 kHz) + 20*log (pilot/f) – Vaudio0 (19 kHz) where f is FM frequency deviation and pilot is pilot frequency deviation. 1. Connect test equipment as shown in Figure 1. 2. Configure the tuner in standard configuration, except fo r setting in mono operation. Set the tuner in stereo mode. 3. Configure the audio analyzer: a. Set Function = RMS Select. i. Set Bandwidth = BP 3%. ii. Set Units = dBV. iii. Set Frequency Mode = FIX: 1 kHz. 4. Configure generator #1 in FM Analog Modulation in stereo mode as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Carrier frequency = 98.1 MHz. b. RF level = 60 dBµV. c. FM Deviation = 67.5 kHz. d. Mode = Left = Right. e. LFGEN frequency = 1 kHz. f. Pre-emphasis = 75 µs. g. Pilot Deviation = 6.75 kHz. 5. Audio 1 kHz level (dBV) = V 1kHz. 6. Configure audio analyzer frequency mode = FIX: 19 kHz. 7. Audio 19 kHz level (dBV) = V 19kHz. 8. Pilot Rejection (relative to pilot) (dB) = V1 kHz – V19 kHz + 20*log10 (pilot/f) = V1 kHz – V19 kHz – 20. 9. Pilot Rejection (relative to 75 kHz) (d B) = V1 kHz – V19 kHz + 20*log10 (75 kHz/f) = V1 kHz – V19 kHz + 0.91.

Several issues must be considered to make accurate measurements. the Mini-Circuits power combiner is approximately 6 dB for the entire FM band.

Set frequency = 98.1 MHz.
Tune Si468x FMHD receiver in tune mode = 3 for wideband digital only tune mode.

Rate (BER) presented as a separate procedure in section "4.2.2. Sensitivity (Bit Error Rate Based)" on page 32.

Connect test equipment as shown in Figure 1.
Tune the receiver to 98.1 MHz in tune mode 3 (see the Programming Guide, FM_tune_freq command).
Configure the audio analyzer:

b. Set Function = THD+N / SINAD. c. Set Measurement Mode = SINAD. e. Set Filter = A-weighting. f. Set Frequency Limit Low = 30 Hz. g. Set Frequency Limit High = 15000 Hz.

Configure generator #1 in FMHD Digital Modulation as described in “2.2. Signal Generator Settings” with the
Adjust generator #1 RF level, VRF0, until audio analyzer SINAD = 26 dB +/- 1 dB.
Sensitivity (dBm) = VRF0.

Table 4. Si468x FMHD Receiver Test Equipment for FMHD Reception *Note: You can power up the EVB through the USB port for these tests.

32 Rev. 0.5 4.2.2. Sensitivity (Bit Error Rate Based) This test uses a specified test vector and the receiver's built-in bit error rate (BER) measurement feature to determine the receiver's sensitivity 1. Connect test equipment as shown in Figure 1. 2. Tune the receiver to 98.1 MHz in tune mode 3 (see the Programming Guide, FM_Tune_Freq command). 3. Configure generator #1 FMHD Digital Modulation as described in “2.2. Signal Generator Settings” with the following settings: a. Set carrier frequency = 98.1 MHz b. Load BER test vector, IB_FMr208c_e1wfc204.wv 4. Disable generator #2. 5. Start the receiver BER test feature using the FMHD_TEST_BER_CONFIG property (see the Programming Guide for details). 6. Adjust generator #1 RF level, VRF0, until the BER reported = 5e-5. a. Note that if the receiver is re-tuned, you must restart the BER test b. Audio will not be output wh ile the BER test is enabled 7. Sensitivity (dBm) = VRF0.

Rev. 0.5 33 4.2.3. Input IP3 Test f1 = 102.1 MHz (blocker #1) f2 = 106.1 MHz (blocker #2) 2 x f1 – f2 = 98.1 MHz (tuner frequency 1. Connect test equipment as shown in Figure 1. 2. Make a sensitivity measurement, VRF0, based on audio pe rformance as described in section "4.2.1. Sensitivity (Audio Based)" on page 31. 3. Configure the tuner in standard configuration, except fo r the AGC setting. For this section of the test, set AGC OFF. 4. Configure the audio analyzer: a. Select Analyze. b. Set Function = THD+N / SINAD. i. Set Measurement Mode = SINAD. ii. Select Unit = dB. 5. Configure generator #1in FM Analog Modulation in mono mode as described in section 2.4 with the following settings: a. Carrier frequency = 106.1 MHz. b. RF level = –47 dBm. c. FM Deviation = 22.5 kHz. d. Set LFGEN frequency = 1 kHz. 6. Configure generator #21in FM Analog Modulation in mo no mode as described in section 2.4 with the following settings: a. Carrier frequency = 102.1 MHz. b. RF level = –47 dBm. c. Disable modulation. d. Enable carrier. 7. Simultaneously adjust the generator #1 and generator #2 RF level, VRF1, until SINAD = 26 dB. 8. IP3 (dBµV) = VRF1 + 1/2 (VRF1 – VRF0).

34 Rev. 0.5 4.2.4. 1st Adjacent/2nd Adjacent Selectivity 1. Connect test equipment as shown in Figure 1. 2. Configure generator #1 in FMHD Digital Modulation as described in “2.2. Signal Generator Settings” with the following settings: a. Carrier frequency = 98.1 MHz. b. RF level VRF0 = –65 dBm. c. Load BER test vector, IB_FMr208c_e1wfc204.wv 3. Configure generator #2 in FM Analog Modulation in mono mode as described in “2.2. Signal Generator Settings” with the following settings: a. Carrier frequency = 98.3/97.9 MHz (1st adjacent channel) or b. Carrier frequency = 98.5/97.7 MHz (2nd adjacent channel). c. RF level = –47 dBm. d. FM Deviation = 22.5 kHz. e. LFGEN frequency = 1 kHz. 4. Start the receiver BER test feature using the FMHD_TEST_BER_CONFIG property (see the Programming Guide for details). 5. Adjust generator #2 RF level, VRF1, until the BER reported = 5e-5. a. Note that if the receiver is re-tuned, you must restart the BER test b. Audio will not be output wh ile the BER test is enabled 6. Selectivity (dB) = VRF1 – VRF0.

Rev. 0.5 35 4.2.5. Far-Off Selectivity (+/-4MHz) 1. Connect test equipment as shown in Figure 1. 2. Configure generator #1 in FMHD Digital Modulation as described in “2.2. Signal Generator Settings” with the following settings: a. Carrier frequency = 98.1 MHz. b. RF level VRF0 = –65 dBm. c. Load BER test vector, IB_FMr208c_e1wfc204.wv 3. Configure generator #2 in FM Analog Modulation in mono mode as described in “2.2. Signal Generator Settings” with the following settings: a. Carrier frequency = 102.1/94.1 MHz b. RF level = –47 dBm. c. FM Deviation = 22.5 kHz. d. LFGEN frequency = 1 kHz. 4. Start the receiver BER test feature using the FMHD_TEST_BER_CONFIG property (see the Programming Guide for details). 5. Adjust generator #2 RF level, VRF1, until the BER reported = 5e-5. a. Note that if the receiver is re-tuned, you must restart the BER test b. Audio will not be output wh ile the BER test is enabled 6. Selectivity (dB) = VRF1 – VRF0.

36 Rev. 0.5 4.2.6. Image Rejection 1. Connect test equipment as shown in Figure 1. 2. Configure generator #1 in FMHD Digital Modulation as described in “2.2. Signal Generator Settings” with the following settings: a. Carrier frequency = 98.1 MHz. b. RF level VRF0 = –65 dBm. c. Load BER test vector, IB_FMr208c_e1wfc204.wv 3. Configure generator #2 in FM Analog Modulation in mono mode as described in “2.2. Signal Generator Settings” with the following settings: a. Carrier frequency, –416 kHz offset = 97.684 MHz b. RF level = –47 dBm. c. FM Deviation = 22.5 kHz. d. LFGEN frequency = 1 kHz. 4. Start the receiver BER test feature using the FMHD_TEST_BER_CONFIG property (see the Programming Guide for details). 5. Adjust generator #2 RF level, VRF1, until the BER reported = 5e-5. a. Note that if the receiver is re-tuned, you must restart the BER test b. Audio will not be output wh ile the BER test is enabled 6. Image Rejection (dB) = VRF1 – VRF0.

Figure 5. Si468x Test Setup Table 5. AM Tuner Test Equipment *Note: You can power up the EVB through two Agilent E3646A Power Supplies.

38 Rev. 0.5 5.1. AM Tuner Testing Calibration During testing power combiner and cable losses must be calibrated and factored into each measurement. The calibration is performed by setting the Generator#1 at 1 MHz and 0 dBm and measuring the RF power at the DUT. The calibration factor is either programmed as an offs et to the generator or manually compensated during measurement. All the levels specified in this document are the levels that should be set at the DUT. 5.2. AM Tuner Configuration The AM tuner is set to following common configuration. It is not necessary to set the following properties during AM testing. The user can run the AM tests by configuring the AM frequency and using the power up defaults (by just booting up the tuner using GUI). However, the following setups enhance the measurement speed, and can be used if the user is running automated tests.5.3. AM Tuner Testing Procedures The following procedures describe AM tuner measurements. 5.3.1. Sensitivity Sensitivity of a receiver is a measure of its ability to receive weak signals and produce an audio frequency output of usable magnitude and acceptable quality. Sensitiv ities may be defined with respect to many different characteristics of the output signal. For the purposes of ou r testing, sensitivity is the minimum RF level required to produce an audio output with a specified signal-to-noise and distortion ratio (SINAD), of 20 dB. Note that the sensitivity measurement is defined with respect to SINAD and not SNR. Descriptions for these two measurements will be given in the following sections. 1. Configure the audio analyzer: a. Set Function = THD+N/SINAD. b. Set Measurement Mode = SINAD. c. Set Unit = dB. d. Set Filter = OFF. e. Set Frequency Limit Low = 30 Hz. f. Set Frequency Limit High = 15000 Hz. g. Fundamental = 1000 Hz fixed function. 2. Configure generator #1: a. Set carrier frequency = 1 MHz. b. Select AM Modulation. c. Set AM Modulation Depth = 30%. d. Set source = LFGEN (internal). Set LFGEN frequency = 1 kHz. e. Enable AM modulation. Enable RF carrier. 3. Disable generator #2. 4. Adjust generator #1 RF level, VRF0, until audio analyzer SINAD = 20 dB . 5. Sensitivity = VRF0 (dBuV). Property Value Property Address Property Value to Set Input Frequency 1000 kHz Volume 63 (max) 0x0300 0x003F AGC_Override RF AGC Disabled 0x1700 0x0001

Rev. 0.5 39 5.3.2. SNR The signal-to-noise ratio of a receiver, under specified conditions, is the ratio of the audio frequency output voltage due to the signal to that due to random noise. This test is performed at standard (30%) and High (90%) modulation depth as well as normal (74 dBµV) and strong (120 dBµV) signal levels. 1. Configure the audio analyzer to record noise. a. Set Function = THD+N/SINAD. b. Set Measurement Mode = Noise. c. Set Unit = dB. d. Set Frequency Mode = FIX: 1 kHz. e. Set Filter = OFF. f. Set Frequency Limit Low = 30 Hz. g. Set Frequency Limit High = 15000 Hz. 2. Configure generator #1: a. Set carrier frequency = 1 MHz . b. Set RF level = 60 dBµV. c. Select AM Modulation. d. Set AM Modulation Depth = 30%. (90% for high Modulation depth measurement). e. Set Source = LFGEN (internal). Set LFGEN frequency = 1 kHz. f. Enable AM modulation. Enable RF carrier. 3. Disable generator #2. 4. Record Noise (dB) from analyzer. 5. Record SNR (dB) = Noise (dB). 5.3.3. THD The total harmonic distortion, or THD, is a measurement of the harmonic distortion present at the audio output and is defined as the ratio of the sum of the powers of all harmonic components calculated in RMS fashion to the power of the fundamental. This test is performed at standard (30%) and high (90%) modulation depth as well as normal (74 dBµV) and strong (120 dBµV) signal levels. 1. Configure the audio analyzer: a. Function= THD. b. Measurement Mode= All di. c. Fundamental= 1000 Hz fixed. d. Equalizer = OFF. e. Function Setting = Off (for quick measurement) or Average (for accurate measurement). f. Select Unit = %. 2. Configure generator #1: a. Set carrier frequency = 1 MHz. b. Set RF level = 60 dBµV. c. Select AM Modulation. d. Set AM Modulation Depth = 30% (90% for high Modulation depth measurement). e. Set Source = LFGEN (internal). f. Set LFGEN frequency = 1 kHz. g. Enable AM modulation. Enable RF (carrier). 3. Disable generator #2. 4. Record THD (%).

40 Rev. 0.5 5.3.4. SINAD Signal to noise and distortion (SINAD) is similar to signa l to noise ratio, but includes distortion. A measurement of the whole signal, i.e., the signal plus noise plus distorti on, is made by the audio analyzer. The audio tone is then removed by the analyzer and the remaining noise and distor tion is measured. This test is performed at standard (30%) and High (90%) modulation. depth 1. Configure the audio analyzer: a. Set Function = THD+N/SINAD. b. Set Measurement Mode = SINAD. c. Fundamental: 1000 Hz fixed. d. Filter = OFF. e. Frequency Limit Low = 30 Hz. f. Frequency Limit High = 15000 Hz. g. Function Setting: Off (for quick measuremen t) or Average (for accurate measurement). h. Select Unit = dB. 2. Configure generator #1: a. Set carrier frequency = 1 MHz b. Set RF level = 60 dBµV. c. Select AM Modulation. d. Set AM Modulation Depth = 30% (90% for high Modulation depth measurement). e. Set Source = LFGEN (internal). f. Set LFGEN frequency = 1 kHz. g. Enable AM modulation. Enable RF (carrier). 3. Enable modulation . Enable carrier. 4. Disable generator #2. 5. Record SINAD (dB). 5.3.5. Output Voltage 1. Configure the audio analyzer: a. Set Function = RMS Select. b. Set Bandwidth = BP 3%. c. Set Units = V RMS. d. Set Frequency Mode = FIX: 1 kHz. 2. Configure generator #1: a. Set carrier frequency = 1 MHz. b. Set RF level = 60 dBµV. c. Select AM Modulation. d. Set AM Modulation Depth = 30%. e. Set Source = LFGEN (internal). f. Set LFGEN frequency = 1 kHz. g. Enable AM modulation. Enable RF (carrier). 3. Disable generator #2. 4. Record audio level (Vrms) from the analyzer.

Rev. 0.5 41 5.3.6. Adjacent/Alternate Channel Rejection Rejection is a measure of the performance of a radio receiver to respond only to the tuned transmission (such as a radio station) and reject other signals nearby, such as another broadcast on an adjacent channel. Adjacent channel rejection measures the interference from an unwant ed signal present one band spacing away (9 kHz away). Alternate channel rejection measures the interference from an unwanted signal present two band spacing away (18 kHz away). 1. Configure the audio analyzer: a. Set Function = THD+N/SINAD. b. Set Measurement Mode = SINAD. c. Filter = OFF d. Frequency Limit Low = 30 Hz. e. Frequency Limit High = 15000 Hz f. Set Frequency Mode = FIX: 1 kHz. g. Select Unit = dB. 2. Configure generator #1: a. Set carrier frequency = 1 MHz. b. Set RF level VRF0= 22 dBµV. c. Select AM Modulation. d. Set AM Modulation Depth = 30%. e. Set Source = LFGEN (internal). f. Set LFGEN frequency = 1 kHz. g. Enable AM modulation. Enable RF carrier. 3. Configure generator #2: a. Set carrier frequency = 0.990 MHz (adjacent channel), or b. Set carrier frequency = 0.980 MHz (alternate channel). c. Select AM Modulation. d. Set AM Modulation Depth = 30%. e. Set Source = LFGEN (internal). f. Set LFGEN frequency = 400 Hz. g. Enable AM Modulation. Enable RF carrier. 4. Adjust generator #2 RF level, VRF1, until the sinad = 20 dB. 5. Rejection (dB) = V RF1 – VRF0.

42 Rev. 0.5 5.3.7. Image Rejection This test measures the image rejection at negative 258 kHz offset from the carrier frequency. 1. Configure the audio analyzer: a. Set Function = RMS & S/N. b. Set Units = dBV. 2. Configure generator #1: a. Set carrier frequency = 1 MHz. b. Set AM Modulation Depth = 30%. c. Set Source = LFGEN (internal). d. Set LFGEN frequency = 1 kHz. e. Set signal level VRF1 = 45 dBµV. f. Enable modulation. g. Enable carrier. 3. Configure generator #2: a. Set carrier frequency = 742 kHz. b. Set image level VRF2 = 75 dBµV. c. Enable generator. 4. Set audio analyzer and read the (message) level value VAUDIO0 5. Disable the modulation on generator # 1. 6. Set audio analyzer and read the (image) level value VAUDIO1 7. V AudioRelative = VAUDIO0 – VAUDIO1. 9. Image Rejection = V AudioRelative + VRFRelative. 5.3.8. IP3 Intermodulation distortion in the detected or decoded audio-frequency signal may be caused by non-linearity in the radio-frequency, intermediate-frequency, and detector stages of the receiver. A good measure of intermodulation distortion is IP3. IP3 is the theoretical RF level at which two blockers (VRF 1), offset from the desired frequency by f and 2f, and their intermodulation product. In our test:  f1 = 1100.2 kHz (blocker #1) f2 = 1200 kHz (blocker #2)  2 x f1 – f2 = 1.0004 MHz (400 Hz away from tuner frequency) 1. The IP3 test requires that Si468x receiver should be set in standard configuration except with the RF AGC disabled. RF AGC is disabled by setting property 0x1700 to 1. 2. Configure the audio analyzer: a. Set Function = RMS Select. b. Set Bandwidth = BP 3%. c. Set Units = dBV. d. Set Frequency Mode = FIX: 1 kHz. 3. Configure generator #1 (For the carrier signal): a. Set carrier frequency = 1000 kHz. b. Set RF level = 30 dBµV (VRF_message). c. Select AM Modulation. d. Set AM Modulation Depth = 30%. e. Set Source = LFGEN (internal).

Rev. 0.5 43 f. Set LFGEN frequency = 1 kHz. g. Enable modulation . Enable carrier. 4. Configure generator #2 (For the blocker#1 signal): a. Set carrier frequency = 1100.2 kHz. b. Set RF level = 70 dBµV (VRF_blocker). c. Enable carrier. 5. Configure generator #3 (For the blocker#2 signal): a. Set carrier frequency = 1200 kHz. b. Set RF level = 70 dBµV (VRF_blocker). c. Enable carrier. 6. Read the message level rms value (due to carrier at 1k Hz) displayed in the analyzer by setting fixed frequency to 1000 kHz (Vrms_message (dBV)) 7. Disable modulation on generator #1. 8. Setup Analyzer at fixed frequency of 400 Hz (blocker) 9. Read the blocker level rms value (due to blocker at 400 Hz) displayed in the analyzer (Vrms_blocker (dBV)) 10.Calculate IP3 a. RelativeLevel = (Vrms_message – Vrms_blocker) b. MessageInputLevel = VRF_message + 20.0 x Math.Log10(0.3) c. BlkMessageInputLevel = MessageInputLevel – RelativeLevel d. IP3 = VRF_blocker + ((VRF_blocker – BlkMessageInputLevel)/2)

Several issues must be considered to make accurate measurements. the Mini-Circuits power combiner is approximately 5 dB for the entire AM band.

Tune Si468x AMHD receiver in blend mode = 2.

Rate (BER) presented as a separate procedure in section "6.2.2. Sensitivity (Bit Error Rate Based)" on page 45.

Connect test equipment as shown in Figure 1.
Tune the receiver to 1 MHz in tune mode 2 (see the Programming Guide, AM_tune_freq command).
Configure the audio analyzer:

b. Set Function = THD+N / SINAD. c. Set Measurement Mode = SINAD. e. Set Frequency Limit Low = 30 Hz. f. Set Frequency Limit High = 15000 Hz.

Configure generator #1 in FMHD Digital Modulation as described in “2.2. Signal Generator Settings” with the
Adjust generator #1 RF level, VRF0, until audio analyzer SINAD = 20 dB ±1 dB.
Sensitivity (dBm) = VRF0.

Table 6. Si468x AMHD Receiver Test Equipment for FMHD Reception *Note: You can power up the EVB through the USB port for these tests.

Rev. 0.5 45 6.2.2. Sensitivity (Bit Error Rate Based) This test uses a specified test vector and the receiver's built-in bit error rate (BER) measurement feature to determine the receiver's sensitivity 1. Connect test equipment as shown in Figure 1. 2. Tune the receiver to 1 MHz in tune mode 2 (see the Programming Guide, FM_Tune_Freq command). 3. Configure generator #1 AMHD Digital Modulation as described in “2.2. Signal Generator Settings” with the following settings: a. Set carrier frequency = 1 MHz b. Load BER test vector, IB_FMr208c_e1wfc204.wv 4. Disable generator #2. 5. Start the receiver BER test feature using the AMHD_TEST_BER_CONFIG property (see the Programming Guide for details). 6. Adjust generator #1 RF level, VRF0, until the BER reported = 1e-4. a. Note that if the receiver is re-tuned, you must restart the BER test b. Audio will not be output wh ile the BER test is enabled 7. Sensitivity (dBm) = VRF0.

46 Rev. 0.5 6.2.3. 1st Adjacent/2nd Adjacent Selectivity 1. Connect test equipment as shown in Figure 1. 2. Configure generator #1 in AMHD Digit al Modulation as described in “2.2. Signal Generator Settings” with the following settings: a. Carrier frequency = 1 MHz. b. RF level VRF0 = 32 dBµV. c. Load BER test vector, IB_AMr208a_e1awfb00.wv 3. Configure generator #2 in AM Analog Modulation as described in “2.2. Signal Generator Settings” with the following settings: a. Carrier frequency = 1010/990 kHz (1st adjacent channel) or b. Carrier frequency = 1020/980 kHz (2nd adjacent channel). c. RF level = 50 dBµV. d. Set AM Modulation Depth = 30%. e. Set Source = LFGEN (internal). f. Set LFGEN frequency = 1 kHz. 4. Start the receiver BER test feature using the AMHD_TEST_BER_CONFIG property (see the Programming Guide for details). 5. Adjust generator #2 RF level, VRF1, until the BER reported = 1.0e-4. a. Note that if the receiver is re-tuned, you must restart the BER test b. Audio will not be output wh ile the BER test is enabled 6. Selectivity (dB) = VRF1 – VRF0.

the Mini-Circuits power combiner is approximately 5.2 dB for the entire DAB band.

Set frequency = 207.008 MHz.
Tune Si468x DAB receiver.

determine the receiver's sensitivity.

Connect test equipment as shown in Figure 1 on page 2.
Configure generator #1 DAB Digital Modulation as descri bed in "2.2. Signal Generator Settings" on page 3 with

a. Set carrier frequency = 207.008 MHz. b. Load BER test vector, BER_NullPattern_test2.eti.

Tune the receiver to 207.008 MHz (see the Programming Guide, DAB_Tune_Freq command).
Acquire a list of digital services (see the Pr ogramming Guide, Get_Digital_Service_List command).
Start digital service (see the Programming Guide, Start_Digital_Service).

a. Digital Service ID = 0xE1C00001.

Start the receiver BER test feature using the DAB_Test_Get_BER_Info property (see the Programming Guide
Adjust generator #1 RF level, VRF0, until the BER reported = 1e-4.

a. Note that if the receiver is re-tuned, you must restart the BER test. b. Audio will not be output wh ile the BER test is enabled.

Sensitivity (dBm) = VRF0*

*Note: It is recommended to acquire at least 1 million points for each BER measurement. Table 7. Si468x DAB Receiver Test Equipment for DAB Reception *Note: You can power up the EVB through the USB port for these tests.

48 Rev. 0.5 7.2.2. Sensitivity (Audio Based) 1. Connect test equipment as shown in Figure 2 on page 3. 2. Configure generator #1 DAB Digital Modulation as descri bed in section “2.2. Signal Generator Settings” with the following settings: a. Set carrier frequency = 207.008 MHz. b. Load test vector, SilabsEnsembleTones07.eti. 3. Disable generator #2. 4. Tune the receiver to 207.008 MHz (see the Programming Guide, DAB_Tune_Freq command). 5. Acquire a list of digital services (see the Pr ogramming Guide, Get_Digital_Service_List command). 6. Start digital service (see the Programming Guide, Start_Digital_Service). a. Digital Service ID = 0x0000c000. b. Component = 0x0000. 7. Configure the audio analyzer: a. Select Analyze. b. Set Function = THD+N / SINAD. c. Set Measurement Mode = SINAD. d. Set Unit = dB. e. Set Filter = A-weighting. f. Set Frequency Limit Low = 30 Hz. g. Set Frequency Limit High = 15000 Hz. h. Adjust generator #1 RF level, VRF0, until audio analyzer SINAD < 26 dB. 8. Sensitivity (dBm) = VRF0

Rev. 0.5 49 7.2.3. Adjacent Channel Selectivity 1. Connect test equipment as shown in Figure 1 on page 2. 2. Configure generator #1 as described in “2.2. Signal Generator Settings” with the following settings: a. Frequency = 195.936 MHz. b. RF level = –70 dBm. c. Test Vector = BER_NullPattern_test2.eti. 3. Tune the receiver to 195.936 MHz (see the Programming Guide, DAB_Tune_Freq command). 4. Acquire a list of digital services (see the Pr ogramming Guide, Get_Digital_Service_List command). 5. Start digital service (see the Programming Guide, Start_Digital_Service). a. Digital Service ID = 0xE1C00001. b. Component = 0xE001. 6. Configure generator #2 as described in “2.2. Signal Generator Settings” with the following settings: a. Frequency = 194,224/197,648 MHz (first adjacent), or b. Frequency = 192,512/199,360 M Hz (second adjacent), or c. Frequency = 190,800/201,072 MHz (third adjacent). d. RF level = –47 dBm. e. Test Vector = BER_NullPattern_test2.eti* *Note: Generator #2's output must be compliant to the RF mask specified in Figure 3 of EN50248: Characteristics of DAB Receivers (Aug, 2001). 7. Start the receiver BER test feature using the DAB_Test_Get_BER_Info property (see the Programming Guide for details). 8. Adjust the generator #2 RF level, VRF1, until the BER reported = 1e-4. 9. Selectivity (dB) = VRF1 – VRF0. Note: VRF0 is the RF level of generator #1.

50 Rev. 0.5 7.2.4. Half-Band FM Blocker Selectivity 1. Connect test equipment as shown in Figure 1 on page 2. 2. Configure generator #1 as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Frequency = 195.936 MHz. b. RF level = –65 dBm. c. Test Vector = BER_NullPattern_test2.eti. 3. Tune the receiver to 195.936 MHz (see the Programming Guide, DAB_Tune_Freq command). 4. Acquire a list of digital services (see the Pr ogramming Guide, Get_Digital_Service_List command). 5. Start digital service (see the Programming Guide, Start_Digital_Service). a. Digital Service ID = 0xE1C00001. b. Component = 0xE001. 6. Configure generator #2 in FM Analog Modulation in mono mode as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Frequency = 97.968 MHz. b. RF level = –47 dBm. c. FM Deviation = 22.5 kHz. d. Set LFGEN frequency = 1 kHz. 7. Start the receiver BER test feature using the DAB_Test_Get_BER_Info property (see the Programming Guide for details). 8. Adjust the generator #2 RF level, VRF1, until the BER reported = 1e-4. 9. Selectivity (dB) = VRF1 – VRF0. Note: VRF0 is the RF level of generator #1.

Rev. 0.5 51 7.2.5. FIC Timing 1. Connect test equipment as shown in Figure 1 on page 2. 2. Configure generator #1 as described in "2.2. Signal Generator Settings" on page 3 with the following settings: a. Frequency = 207.008 MHz. b. Test Vector = BER_NullPattern_test2.eti. 3. Configure DAB interrupt source to trigger on acquisition change (see the Programming Guide, DAB_DIGRAD_Interrupt_Source). a. Reg 0xB000 = 0x0004. 4. Enable the interrupt property to issue interrupt based on a digital acquisition interrupt (see the Programming Guide, INT_CTL_Enable). a. Reg 0x0000 = 0x0002. 5. Clear the interrupt due to the change in acquis ition (see the Programming Guide, DIGRAD_ACK). 6. Place a probe on SSB signal and a probe on INTb signal. 7. Tune the receiver to 207.008 MHz (see the Programming Guide, DAB_Tune_Freq command). 8. Capture the following timing: a. Capture the last rising edge of SSB after the tuning command is issued (T0). b. Capture the fallin g edge of the INTb line (T1). 9. Ensemble Acquisition time = T1 – T0.

52 Rev. 0.5 7.3. Stereo THD 1. Connect test equipment as shown in Figure 2 on page 3. 2. Configure generator #1 DAB Digital Modulation as described in section “2.2. Signal Generator Settings” with the following settings: a. Set carrier frequency = 207.008 MHz. b. Load BER test vector, SilabsEnsembleTones07.eti. 3. Configure the audio analyzer: a. Set Function = THD. b. Set Measurement Mode = All di (all harmonics). c. Fundamental = 1000 Hz Fixed. d. Equalizer = Off. e. Function Settling = Off (for quick measuremen t) or Average (for accurate measurement). f. Select Unit = %. 4. Tune the receiver to 207.008 MHz (see the Programming Guide, DAB_Tune_Freq command). 5. Acquire a list of digital services (see the Pr ogramming Guide, Get_Digital_Service_List command). 6. Start digital service (see the Programming Guide, Start_Digital_Service). a. Digital Service ID = 0x0000C000. b. Component = 0x0000. 7. Disable generator #2. 8. Record THD (%).

Rev. 0.5 53 7.4. Stereo SNR 1. Connect test equipment as shown in Figure 2 on page 3. 2. Configure generator #1 DAB Digital Modulation as descri bed in section “2.2. Signal Generator Settings” with the following settings: a. Set carrier frequency = 207.008 MHz. b. Load BER test vector, SilabsEnsembleTones07.eti. 3. Configure the audio analyzer: a. Set Function = THD+N / SINAD. b. Set Measurement Mode = NOISE. c. Set Units = dB d. Set Filter = A-weighting. e. Set Frequency Limit Low = 300 Hz. f. Set Frequency Limit Upper = 15000 Hz. g. Function Settling = Off (for quick measuremen t) or Average (for accurate measurement). 4. Tune the receiver to 207.008 MHz (see the Programming Guide, DAB_Tune_Freq command). 5. Acquire a list of digital services (see the Pr ogramming Guide, Get_Digital_Service_List command). 6. Start digital service (see the Programming Guide, Start_Digital_Service). a. Digital Service ID = 0x0000C000. b. Component = 0x0000. 7. Record SNR (dB) = Noise (dB).

54 Rev. 0.5 7.5. Stereo SINAD 1. Connect test equipment as shown in Figure 2 on page 3. 2. Configure generator #1 DAB Digital Modulation as described in section “2.2. Signal Generator Settings” with the following settings: a. Set carrier frequency = 207.008 MHz. b. Load BER test vector, SilabsEnsembleTones07.eti. 3. Configure the audio analyzer: a. Set Function = THD+N / SINAD. b. Set Measurement Mode = SINAD c. Set Units = dB. d. Set Filter = A-weighting. e. Set Frequency Limit Low = 300 Hz. f. Set Frequency Limit Upper = 15000 Hz. g. Set Function Settling = Off (for quick measurement) or Average (for accurate measurement) 4. Record SINAD (dB) = SINAD (dB).

Rev. 0.5 55 APPENDIX A—P RE-EMPHASIS AND DE-EMPHASIS A review of FM modulation can be used to understand t he effect of pre-emphasis on the spectrum. For a single- tone message, the modulated signal can be represented as with a modulation index,  The bandwidth of this signal would be approximately: The frequency response of a pre-emphasis filter is shown in Figure 6. Depending on the region, a time constant of either 50 or 75 µs is used. This time constant affects th e range of frequencies that will be emphasized by the filter. Also, the increase in signal at higher frequencies depends on the time constant of this filter. For a 75 µs filter, 15 kHz would get an increase of 5.3 times relative to 1 k Hz, whereas a 50 µs filter would provide an increase on the order of 4.8 times relative to 1 kHz. m(t) A m 2fmt message signalcos= s(t) A c 2fct RF carriercos= s(t) A c 2fct2 kf m(t)dt t Ac 2fct kfAm fm cos= cos= kfAm fm fm ----- freq deviation BWs(t) 2 ff m+

Rev. 0.5 59 DOCUMENT CHANGE LIST Revision 0.1 to Revision 0.2  Updated tests to reflect P2 release Revision 0.2 to Revision 0.3  Changed flow so that Audio and RF tests are together. Revision 0.3 to Revision 0.4  Changed “Si46xx” to “Si468x” throughout. Revision 0.4 to Revision 0.5  Added "5. AM Analog Radio Testing" on page 37.  Added step on page 43.  Added "6. AMHD Radio Testing" on page 44.

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AN651 specifications and overview.

Summary

EVALUATION BOARD TEST PROCEDURE

Description

EVALUATION BOARD TEST PROCEDURE

Source title AN651 Datasheet(PDF) - Silicon Laboratories

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