CMX017 ETC

Document overview

  • Manufacturer or author: Provided By www.digicamel.com(FREE DATASHEET DOWNLOAD SITE)
  • PDF pages: 12

Technical content

Datasheet sections

  • 1 Block Diagram
  • 2 Signal List
  • 3 External Components
  • 4 General Description
  • 4.1 FM/FSK Modulator + PA Driver
  • 4.2 Power Amplifier (PA)
  • 4.3 Power-Down Modes
  • 5 Application Notes
  • 5.1 Generation of the Modulated RF Signal
  • 5.2 Power-Down Modes
  • 6 Performance Specification
  • 6.1 Electrical Performance
  • 6.1.1 Absolute Maximum Ratings
  • 6.1.2 Operating Limits
  • 6.1.3 Operating Characteristics
  • 6.1.4 Packaging

CMX017 UHF FM/FSK Transmitter 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies ADVANCE INFORMATION Features Applications

  • Direct FM/FSK UHF Modulator
  • Adjustable Modulator Output Power
  • Integrated Power Amplifier with Output Power up to +20dBm (100mW)
  • Low Power 2.7V Operation
  • Powersave and Zero-Power (<10µA) Modes
  • 28-Pin SSOP Package
  • General Radio Link 860-965MHz
  • General 915MHz ISM Band (USA)
  • Spread Spectrum Wireless Systems
  • Fixed Frequency Transmissions
  • Analog/Digital Cordless Phones
  • Handheld Data Terminals
  • SO-HO Wireless Data Links BANDGAP & BIAS CONTROL ENLMOD ENLPAOSCOUT BUFFERED OSCILLATOR OUTPUT TANK MODIN FM/FSK MODULATOR POWER AMPLIFIER DRIVER GAIN MODOUT PAIN IPAOUT POWER AMPLIFIER PAOUT The CMX017 is a single chip UHF FM/FSK transmitter that combines both the RF VCO Modulator and RF Power Amplifier. It is suitable for both audio FM and digital FSK transmissions. A buffered oscillator output provides the RF signal drive to an external synthesizer or fixed frequency phase- locked loop for channel frequency selection. Modulator output power is adjustable over a 20dB range and the integrated power amplifier delivers up to +20dBm. The device also includes a powersave mode: “Transmit Standby” and a zero-power mode: “Sleep”. These allow independent power down control of both the modulator and power amplifier, thereby maximizing battery life. The device can be used in conjunction with the CMX018, a double-conversion super-heterodyne receiver, to implement a complete UHF radio link. The CMX017 operates from a 2.7V to 3.3V power supply and is available in the following package style: 28-pin SSOP (CMX017D6).

UHF FM/FSK Transmitter 3 CMX017 Advance Information 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies

1 Block Diagram

Figure 1: Internal Block Diagram

UHF FM/FSK Transmitter 4 CMX017 Advance Information 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies

2 Signal List

Pin No. Signal

Description

1V CC 3 power Power amplifier (first stage) power supply - nominally 3.0V

2 GAIN input Modulator output (pin 26) - Power control

3 GND ground Ground-plane connection to the power amplifier

4 GND ground Ground-plane connection to the power amplifier

5 GND ground Ground-plane connection to the power amplifier

6 IPAOUT output Output (open-collector) from the first stage of the power

7 GND ground Ground-plane connection to the power amplifier

8 GND ground Ground-plane connection to the power amplifier

9 PAOUT output Output (open-collector) from the second stage of the power

10 GND ground Ground-plane connection to the power amplifier

11 GND ground Ground-plane connection to the power amplifier

12 V CC 4 power Power amplifier (second stage) power supply

– nominally 3.0V

13 ENLPA CMOS

Power Amplifier powersave logic control. A logic “0” powers down the Power Amplifier and Driver stages

14 GND ground Ground-plane connection

15 GND ground Ground-plane connection

16 ENLMOD CMOS

Modulator zero-power logic control. A logic “0” powers down the Modulator and Buffered Oscillator stages

17 GND ground Ground-plane connection

18 MODIN input Baseband modulation input signal

19 GND ground Ground-plane connection to the VCO

20 TANK input VCO Tank circuit/Resonator connection

21 GND ground Ground-plane connection to the modulator and VCO buffer

22 V CC 1 power Modulator power supply – nominally 3.0V

23 OSCOUT output Buffered Oscillator (open-collector) output

24 V CC 2 power Power Amplifier Driver power supply - nominally 3.0V

25 GND ground Ground-plane connection for the Power Amplifier Driver

26 MODOUT output Modulator output

27 GND ground Ground-plane connection for the Power Amplifier Driver

28 PAIN input Power Amplifier input

Table 1: Signal List

UHF FM/FSK Transmitter 5 CMX017 Advance Information 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies

3 External Components

V CC4 ENLPA GND PAI N GND MODOUT GND VCC2 OSCOUT V CC1 GND TANK GND MODIN GND ENLMOD GND POWER CONTROL BASE-BAND ENABLE MODULATORENABLE POWER AMPLIFIER RF to PLL From PLL C DEC C10 C11 C12 L1 L4 RESONA TOR CDEC 100pF10nF1F/c109CDEC /c186 Tx SIGNAL R1R1 R3 SMD POT Figure 2: Example of CMX017 with External Components C1 5.6pF C12 100pF C2 33pF D1 Varactor Varactor diode, type SMV1233-011 C3 4.3pF ~ Resonator Co-Axial Resonator, type RG402, length = 11mm, shorted end C4 TBD L1 1.5nH C5 100pF L2 22nH C6 100pF L3 6.8nH C7 100pF L4 22nH C8 100pF R1 10kΩ C9 100pF R2 10kΩ C10 100pF R3 TBD Value is application dependent C11 100pF R4 TBD SMD potentiometer - value is application dependent Note: Components are surface mount, type SMD0603, unless otherwise indicated. Figure 3: Example of CMX017 with External Components for 915MHz Operation

UHF FM/FSK Transmitter 6 CMX017 Advance Information 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies

4 General Description

The CMX017 is a single chip UHF FM/FSK transmitter that combines both the RF VCO Modulator and RF Power Amplifier. It is suitable for both audio FM and digital FSK transmissions. A buffered oscillator output provides the RF signal drive to an external synthesizer or fixed frequency phase- locked loop for channel frequency selection. Modulator output power is adjustable over a 20dB range and the integrated power amplifier delivers up to +20dBm. The device also includes a powersave mode: “Transmit Standby” and a zero-power mode: “Sleep”. These allow independent power down control of both the modulator and power amplifier, thereby maximizing battery life. The device can be used in conjunction with the CMX018 a double-conversion super-heterodyne receiver, to implement a complete UHF radio link.

4.1 FM/FSK Modulator + PA Driver

The modulator circuit uses an integrated oscillator whose frequency can be directly modulated by the DC- coupled input base-band signal, at the MODIN pin, to generate a frequency modulated (FM or FSK) RF signal. The oscillator requires an external varactor and resonator circuit, connected at the TANK pin, to tune to the required RF channel. A buffered oscillator signal is provided from an open-collector output, at the OSCOUT pin, to drive an external frequency synthesizer for the channel selection. The output power, at the MODOUT pin, is variable over a 20dB range. The output power is maximum when the GAIN pin is connected to V CC and is reduced by typically 20dB when this pin is connected to 0V. The output impedance at the MODOUT pin is typically 50Ω .

4.2 Power Amplifier (PA)

The power amplifier has two internal stages, each biased for class-B operation, and is designed to have a fixed overall power gain. The input and output impedances can be terminated with 50Ω . A typical power gain improvement of 2dB is achieved using simple external matching networks.

4.3 Powersave and Zero-Power Modes

The Modulator and Buffered Oscillator stages are powered down independently of the PA Driver + Power Amplifier stages by means of the ENLMOD and ENLPA logic inputs: A logic ‘0’ at ENLMOD powers down the Modulator and Buffered Oscillator stages. A logic ‘0’ at ENLPA powers down the PA Driver and Power Amplifier stages. Refer to the block diagram in Figure 1 and to Section 5.

5 Application Notes

5.1 Generation of the Modulated RF Signal

The modulator on the CMX017 relies on the direct modulation of the RF Voltage Controlled Oscillator (VCO), which is stabilized to the channel center frequency by an external Frequency Synthesizer or Phase Locked Loop (PLL). The user has control over the external PLL filter and VCO tank components and choice of these components will have an impact upon the following PLL parameters:- Closed loop bandwidth, settling time and transient response Modulation linearity VCO phase noise Three modulation requirements may be achieved as follows:

5.1.1 The minimum modulation signal frequency is above the PLL Closed Loop Bandwidth

In applications where the transmit channel frequency is fixed or occasionally changed, a narrow PLL bandwidth can be chosen such that the minimum modulation frequency is in excess of the PLL bandwidth. With the PLL active whilst the base-band signal is applied to the modulator there will be negligible distortion of the modulated RF output signal. A benefit of this technique is that an output phase noise improvement is achieved, compared to the free running VCO phase noise characteristic.

5.1.2 The minimum modulation signal frequency is within the PLL Closed Loop Bandwidth

In Frequency Hopped Spread Spectrum applications the frequency synthesizer must be agile. Consequently the PLL bandwidth should be designed to achieve the required hop-rate and, in most systems this bandwidth will exceed the minimum modulation frequency. With the PLL active during modulation, the loop will

UHF FM/FSK Transmitter 7 CMX017 Advance Information 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies compensate for the signal frequency components within the loop bandwidth, introducing a frequency dependant distortion of the modulated RF output signal. To avoid the modulation distortion the carrier frequency is tuned by the external synthesizer chip, with no modulating signal applied. The synthesizer control is then disabled, by setting the charge-pump output of the synthesizer to tri-state. The DC coupled base-band signal, applied to the MODIN pin, then modulates the free running VCO to generate the FM or FSK output signal.

5.1.3 A flat modulator response is required down to DC, whilst benefiting from the phase noise

improvements due to the PLL (Two-Point Modulation). Unlike in the above two cases, where a fixed reference frequency is used in the PLL, the Two-Point Modulation technique requires modulation inputs to both the PLL reference oscillator and to the RF VCO circuits. The modulation signal should be applied to both modulation inputs with suitable AC/DC levels and with the correct phase to achieve cancellation of the loop’s feedback. This prevents the radio’s PLL circuitry from counteracting the modulation process and so provides a clean flat modulation response down to DC.

5.2 Powersave and Zero-Power Modes

It is possible to power down each section of the transmitter independently. This feature may be useful when the CMX017 is configured, with the CMX018, as a radio transceiver. It allows the transmitter to be powered on and off, thereby saving power, during the sleep and standby periods. In SLEEP mode (ENLMOD=’0’ and ENLPA=’0’) all sections of the device are powered down and the current consumption is reduced to less than 10µA. This is the zero-power mode. In TRANSMIT-STANDBY mode (ENLMOD=’1’ and ENLPA=’0’) only the PA Driver and Power Amplifier stages are powered down, while the Modulator and Buffered Oscillator remain active. This powersave mode allows the external frequency synthesizer to stabilize the channel center frequency prior to the RF transmission. In TRANSMIT mode (ENLMOD=’1’ and ENLPA=’1’) both the Modulator and the Power Amplifier sections of the device are fully operational. Note: The device can be used as a stand alone “UHF Power Amplifier” by forcing (ENLMOD=’0’ and ENLPA=’1’). The efficiency is maximized by connecting the V CC 2 pin to 0V. (The VCC 1 pin must remain connected to 3.0V.)

5.3 Lower Output Power Applications

For very short range applications the antenna drive can be taken from the modulator output, MODOUT, at pin 26. The Power Amplifier is powered down by connecting VCC 3 and VCC 4 (pins 1 and 12) to 0V. This allows the supply current to be minimized and the Modulator output to be enabled or disabled using the ENLPA input at pin 13.

5.4 Example Schematic and Layout

The following schematic (Figure 4) and printed circuit layout (Figure 5 and Figure 6) present a typical application interface for the CMX017. To aid legibility, the schematic and layout are available electronically from the MX-COM website http://www.mxcom.com. Alternative components and component values are shown on the schematic. These should be selected according to the intended application. The schematic uses the following ICs: U2 IC Works WB1315X U4 Analog Devices AD8532-SO8

UHF FM/FSK Transmitter 8 CMX017 Advance Information 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies C46 100pF C43 1uF 10nF C58 100nF C57 100uF C56 15uHL9 1 3 5 7 2 4 6 8 9 11 13 15 17 19 10 12 14 16 18 20 TFMCON20M C40100pF 100uF C45 C41 100pF 100pF C39 100pF C145 100pFC48 R100100 C42 100pF 100pF C37 C44 100pF C31 100pF 15uH 100nF C32 100pF C33 2.2uF C34 SYNT_DATASYNT_STBSYNT_CLK C38 1nF NF NF NF 100k R21 100k R22 100k R23 CLOCK DATA LE GND FIN2B FIN2 GND DO2 VP2 VCC2 VCC1 VP1 DO1 GND FIN1 FIN1B GND OSC_IN GND FO_LD WB1315X C65 N/C C1933pF C1612pF C12100pF 100nH 100uF 100pF 100pF 1.5nH C10100pF R1410K L5 22nH 100pF C15 CMX017D6 VCC4 PAOUT IPAOUT GND ENLPA VCC3 GAIN GND ENLMOD MODIN TANK VCC1 OSCOUT VCC2 MODOUT PAIN GND3 GND2 GND1 OSCGND GND GND4 GND5 GND6 GND7 GND8 GND9 GND10 L6 20nH 100nFC6

1 GND 2IN

C14 6.8pF C13 4.7pF C18 100pF 100pF C11 100pF 100nH C26 100pF C1 5.6pFC2 33pF 6.8nH N/C N/CR1 10k R9 0R R2 100R 10nF 3pF C24 1nFC27 2.2uF R13 47kL7 15uH R17 47k R18 0R C35 470nF R19 1k C36 100nF N/C N/C 100pF C22 AD8532-SO8 ( - N/C) Figure 4: Application Schematic

UHF FM/FSK Transmitter 10 CMX017 Advance Information 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies

6 Performance Specification

6.1 Electrical Performance

6.1.1 Absolute Maximum Ratings

Exceeding these maximum ratings can result in damage to the device. Pin Min. Max. Units Supply (VCC ) 1, 12, 22, -0.3 7.0 V Input Voltage 2, 13, 16, 18, 20 -0.3 V CC + 0.3 V Power Amplifier Input Power 28 +7 dBm Total Allowable Power Dissipation at TAMB = 25°C 1100 mW Derating above 25°C 11 mW/°C above 25°C Storage Temperature -55 +125 °C Table 2: Absolute Maximum Ratings

6.1.2 Operating Limits

Correct operation of the device outside these limits is not implied. Notes Min. Max. Units Supply (VCC )2 . 7 3 . 3 V Operating Frequency Range 860 965 MHz Operating Temperature -10 +60 °C Table 3: Operating Limits

6.1.3 Operating Characteristics

For the following conditions unless otherwise specified: VCC = 2.7V to 3.3V, TAMB = -10°C to +60°C, RF = 915MHz, 50Ω source and load impedance. Pin Note Min. Typ. Max. Units DC Parameters Device Fully Enabled (ENLPA=HI and ENLMOD=HI) ICC [Output Power = +20dBm at PAOUT (pin 9)] 1 - 130 - mA ICC [Output Power = +10dBm at PAOUT (pin 9)] 1 - 60 - mA ICC [Output Power = +0dBm at PAOUT (pin 9)] 1 - 40 - mA Device in Power-Down Modes ICC in STANDBY mode (ENLPA=LO and ENLMOD=HI) 1- 2 4 -m A ICC in SLEEP Mode (ENLPA=LO and ENLMOD=LO) 1- T B D 1 0 µA

UHF FM/FSK Transmitter 11 CMX017 Advance Information 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies Pin Note Min. Typ. Max. Units AC Parameters Modulator, VCO Buffer and PA Driver Output Power [GAIN (pin 2) at VCC ]2 6 - - 4 . 0 - d B m Output Power [GAIN (pin 2) at 1.5V] 26 - -9.0 - dBm Output Power [GAIN (pin 2) at 1.0V] 26 - -14 - dBm Buffered VCO Output at OSCOUT pin 19 2 - -10 - dBm Oscillator Second Harmonic Output 26 3 - -25 - dBc Oscillator Third Harmonic Output 26 3 - -35 - dBc Modulation Sensitivity 18 4 - 0.4 - MHz/V Maximum Deviation 26 5 - 1.5 - MHz Input Data Rate 18 - - TBD kBits/S Output VSWR (at maximum output power) 26 - TBD - Power Amplifier Power Gain 28, 9 - 22 - dB Power Gain (with external matching at VCC = 3.3V) 28, 9 - 24 - dB Maximum Power Gain Variation 28, 9 6 - 2.0 - dB Maximum Power Gain Variation (with matching) 28,9 6 - 1.5 - dB Input 1dB Compression Point 9 - +1.0 - dBm Input 1dB Compression Point (with matching) 9 - 0 - dBm Reverse Isolation 9, 28 - -35 - dB Output VSWR (at maximum output power) 9 - TBD - dB Notes: 1. Total current from the external 3V power supply. 2. Power measured into a 50Ω load. 3. With external matching. 4. Stepped modulation voltage input from 1.0V to 2.0V. 5. Stepped modulation voltage from 0V to 3.0V. 6. Input Power = -15dBm to -1dBm.

UHF FM/FSK Transmitter 12 CMX017 Advance Information 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies

6.2 Packaging

Figure 7: 28-Pin Plastic SSOP Mechanical Outline: Order as part no. CMX017D6

6.3 Handling Precautions

As this device is a high performance RF integrated circuit and is ESD sensitive. Adequate precautions must be taken during handling and assembly of this device.