AD605AR

AD605 AD | Alldatasheet

Document overview

• Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
• PDF pages: 12

Technical content

REV. C a AD605 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Tel: 781/329-4700 www.analog.com Fax: 781/326-8703 © 2004 Analog Devices, Inc. All rights reserved. Dual, Low Noise, Single-Supply Variable Gain Amplifier FUNCTIONAL BLOCK DIAGRAM PRECISION PASSIVE INPUT ATTENUATOR FIXED GAIN AMPLIFIER +34.4dB DIFFERENTIAL ATTENUATOR 0 TO –48.4dB OUT VOCM VGN VREF +IN –IN GAIN CONTROL AND SCALING FBK AD605

FEATURES

Two Independent Linear-in-dB Channels Input Noise at Maximum Gain: 1.8 nV/ √Hz, 2.7 pA/ √Hz Bandwidth: 40 MHz (–3 dB) Differential Input Absolute Gain Range Programmable: –14 dB to +34 dB (FBK Shorted to OUT) Through 0 dB to +48 dB (FBK Open) Variable Gain Scaling: 20 dB/V Through 40 dB/V Stable Gain with Temperature and Supply Variations Single-Ended Unipolar Gain Control Output Common-Mode Independently Set Power Shutdown at Lower End of Gain Control Single 5 V Supply Low Power: 90 mW/Channel Drives A/D Converters Directly

APPLICATIONS

Ultrasound and Sonar Time-Gain Control High Performance AGC Systems Signal Measurement GENERAL DESCRIPTION The AD605 is a low noise, accurate, dual channel, linear-in-dB variable gain amplifier, which is optimized for any application requiring high performance, wide bandwidth variable gain con- trol. Operating from a single 5 V supply, the AD605 provides differential inputs and unipolar gain control for ease of use. Added flexibility is achieved with a user-determined gain range and an external reference input which provides user-determined gain scaling (dB/V). The high performance linear-in-dB response of the AD605 is achieved with the differential input, single supply, exponential amplifier (DSX-AMP) architecture. Each of the DSX-AMPs comprise a variable attenuator of 0 dB to –48.4 dB followed by a high speed fixed gain amplifier. The attenuator is based on a 7-stage R-1.5R ladder network. The attenuation between tap points is 6.908 dB, and 48.360 dB for the entire ladder network. The DSX-AMP architecture results in 1.8 nV/ √Hz input noise spectral density and will accept a ± 2.0 V input signal when VOCM is biased at VP/2. Each independent channel of the AD605 provides a gain range of 48 dB which can be optimized for the application. Gain ranges between –14 dB to +34 dB and 0 dB to +48 dB can be selected by a single re sistor between pins FBK and OUT. The lower and upper gain ranges are determined by shorting pin FBK to OUT, or leaving pin FBK unconnected, respectively. The two channels of the AD605 can be cascaded to provide 96 dB of very accurate gain range in a monolithic package. The gain control interface provides an input resistance of approxi- mately 2 MΩ and scale factors from 20 dB/V to 30 dB/V for a VREF input voltage of 2.5 V to 1.67 V, respectively. Note that scale factors up to 40 dB/V are achievable with reduced accu- racy for scales above 30 dB/V. The gain scales linearly in dB with control voltages (VGN) of 0.4 V to 2.4 V for the 20 dB/V scale and 0.20 V to 1.20 V for the 40 dB/V scale. When VGN is <50 mV the amplifier is powered down to draw 1.9 mA. Under normal operation, the quiescent supply current of each amplifier channel is only 18 mA. The AD605 is available in 16-lead PDIP and SOIC, and is guaranteed for operation over the –40 °C to +85 °C tempera- ture range.

AD605–SPECIFICATIONS –2– REV. C Model AD605A AD605B Parameter Conditions Min Typ Max Min Typ Max Unit INPUT CHARACTERISTICS Input Resistance 175 ± 40 175 ± 40 Ω Input Capacitance 3.0 3.0 pF Peak Input Voltage At Minimum Gain 2.5 ± 2.5 2.5 ± 2.5 V Input Voltage Noise VGN = 2.9 V 1.8 1.8 nV/ √Hz Input Current Noise VGN = 2.9 V 2.7 2.7 pA/ √Hz Noise Figure R S = 50 Ω, f = 10 MHz, VGN = 2.9 V 8.4 8.4 dB RS = 200 Ω, f = 10 MHz, VGN = 2.9 V 12 12 dB Common-Mode Rejection Ratio f = 1 MHz, VGN = 2.65 V –20 –20 dB OUTPUT CHARACTERISTICS –3 dB Bandwidth Constant with Gain 40 40 MHz Slew Rate VGN = 1.5 V, Output = 1 V Step 170 170 V/ µs Output Signal Range R L ≥ 500 Ω 2.5 ± 1.5 2.5 ± 1.5 V Output Impedance f = 10 MHz 2 2 Ω Output Short-Circuit Current ± 40 ± 40 mA Harmonic Distortion VGN = 1 V, VOUT = 1 V p-p, HD2 f = 1 MHz –64 –64 dBc HD3 f = 1 MHz –68 –68 dBc HD2 f = 10 MHz –51 –51 dBc HD3 f = 10 MHz –53 –53 dBc Two-Tone Intermodulation R S = 0 Ω, VGN = 2.9 V, VOUT = 1 V p-p Distortion (IMD) f = 1 MHz –72 –72 dBc f = 10 MHz –60 –60 dBc 1 dB Compression Point f = 10 MHz, VGN = 2.9 V, Output Referred +15 +15 dBm Third Order Intercept f = 10 MHz, VGN = 2.9 V, VOUT = 1 V p-p, –1 –1 dBm Input Referred Channel-to-Channel Crosstalk Ch1: VGN = 2.65 V, Inputs Shorted, –70 –70 dB Ch2: VGN = 1.5 V (Mid Gain), f = 1 MHz, VOUT = 1 V p-p Group Delay Variation 1 MHz < f < 10 MHz, Full Gain Range ± 2.0 ± 2.0 ns VOCM Input Resistance 45 45 k Ω ACCURACY Absolute Gain Error Gain Scaling Error 0.4 V < VGN < 2.4 V ± 0.25 ± 0.25 dB/V Output Offset Voltage VREF = 2.500 V, VOCM = 2.500 V –50 ± 30 50 –50 ± 30 50 mV Output Offset Variation VREF = 2.500 V, VOCM = 2.500 V 30 95 30 50 mV GAIN CONTROL INTERFACE Gain Scaling Factor VREF = 2.5 V, 0.4 V < VGN < 2.4 V 19 20 21 19 20 21 dB/V VREF = 1.67 V 30 30 dB/V Gain Range FBK Short to OUT –14 – +34 –14 – +34 dB FBK Open 0 – +48 0 – +48 dB Input Bias Current –0.4 –0.4 µA Input Resistance 22 M Ω Response Time 48 dB Gain Change 0.2 0.2 µs POWER SUPPLY Power Dissipation 90 90 mW VREF Input Resistance 10 10 k Ω Quiescent Supply Current VPOS 18 23 18 23 mA Power Down VPOS, VGN < 50 mV 1.9 3.0 1.9 3.0 mA Power-Up Response Time 48 dB Gain, V OUT = 2 V p-p 0.6 0.6 µs Power-Down Response Time 0.4 0.4 µs (Each channel @ TA = 25/H11543C, VS = 5 V, RS = 50 /H9024, RL = 500 /H9024, CL = 5 pF, VREF = 2.5 V (Scaling = 20 dB/V), –14 dB to +34 dB gain range, unless otherwise noted.)

–3–REV. C ABSOLUTE MAXIMUM RATINGS * Supply Voltage +VS Internal Power Dissipation *Stresses above those listed under Absolute Maximum Ratings may cause perma- nent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ORDERING GUIDE Model Temperature Range Package Description Package Option /H9258JA AD605AN –40 °C to +85°C PDIP N-16 85 °C/W AD605AR –40 °C to +85°C SOIC R-16 100 °C/W AD605AR-REEL –40 °C to +85°CS OIC 13" Reel R-16 100 °C/W AD605AR-REEL7 –40 °C to +85°CS OIC 7" Reel R-16 100 °C/W AD605BN –40 °C to +85°C PDIP N-16 85 °C/W AD605BR –40 °C to +85°C SOIC R-16 100 °C/W AD605BR-REEL –40 °C to +85°CS OIC 13" Reel R-16 100 °C/W AD605BR-REEL7 –40 °C to +85°CS OIC 7" Reel R-16 100 °C/W AD605ACHIPS DIE AD605-EB Evaluation Board PIN FUNCTION DESCRIPTIONS 16-Lead Package for Dual Channel AD605 Pin No. Mnemonic Description 1 VGN1 CH1 Gain-Control Input and Power-Down Pin. If grounded, device is off, otherwise positive voltage increases gain. 2 –IN1 CH1 Negative Input. 3 +IN1 CH1 Positive Input. 4G ND1 Ground. 5G ND2 Ground. 6 +IN2 CH2 Positive Input. 7 –IN2 CH2 Negative Input. 8 VGN2 CH2 Gain-Control Input and Power-Down Pin. If grounded, device is off, otherwise positive voltage increases gain. 9 VOCM Input to this pin defines common-mode voltage for OUT1 and OUT2. 10 OUT2 CH2 Output. 11 FBK2 Feedback Pin that Selects Gain Range of CH2. 12 VPOS Positive Supply. 13 VPOS Positive Supply. 14 FBK1 Feedback Pin that Selects Gain Range of CH1. 15 OUT1 CH1 Output. 16 VREF Input to this pin sets gain-scaling for both channels: 2.5 V = 20 dB/V, 1.67 V = 30 dB/V. PIN CONFIGURATION TOP VIEW (Not to Scale) AD605 VGN1 VPOS FBK1 OUT1 VREF –IN1 +IN1 GND1 OUT2 FBK2 VPOSGND2 +IN2 –IN2 VGN2 VOCM CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the AD605 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high-energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality.

VGN (V) GAIN (dB) –20 –10 TPC 1. Gain vs. VGN VREF (V) GAIN SCALING (dBV) 40.0 37.5 20.0 30.0 27.5 25.0 22.5 35.0 32.5 THEORETICAL ACTUAL TPC 4. Gain Scaling vs. V REF TPC 7. Gain Error vs. VGN for Different Gain Scalings VGN (V) GAIN (dB) –20 –10 FBK (OPEN) FBK (SHORT) TPC 2. Gain vs. VGN for Different Gain Ranges VGN (V) GAIN ERROR (dB) 3.0 2.5 –3.0 –1.0 –1.5 –2.0 –2.5 2.0 1.0 1.5 –0.5 0.5 0.0 –40 C +85 C +25 C TPC 5. Gain Error vs. VGN at Different Temperatures DELTA GAIN (dB) PERCENTAGE 0.6 0.8 /H9004G(dB) = G(CH1) – G(CH2) N = 50 TPC 8. Gain Match, VGN1 = VGN2 = 1.0 V (VREF = 2.5 V (20 dB/V Scaling), f = 1 MHz, R L = 500 /H9024, CL = 5 pF, TA = 25/H11543C, VSS = 5 V) AD605–Typical Performance Characteristics (per Channel) –4– REV. C VGN (V) GAIN (dB) –20 –10 30dB/V (VREF = 1.67V) 20dB/V (VREF = 2.50V) ACTUAL ACTUAL TPC 3. Gain vs. VGN for Different Gain Scalings VGN (V) GAIN ERROR (dB) 2.0 1.5 –2.0 0.0 –0.5 –1.0 –1.5 1.0 0.5 f = 1MHz f = 5MHz f = 10MHz TPC 6. Gain Error vs. VGN at Different Frequencies DELTA GAIN (dB) PERCENTAGE /H9004G(dB) = G(CH1) – G(CH2) N = 50 TPC 9. Gain Match, VGN1 = VGN2 = 2.50 V

–5–REV. C FREQUENCY (Hz) GAIN (dB) –60 100k 1M 100M 10M –20 –40 VGN = 2.9V (FBK = OPEN) VGN = 2.9V (FBK = SHORT) VGN = 1.5V (FBK = OPEN) VGN = 1.5V (FBK = SHORT) VGN = 0.1V (FBK = OPEN) VGN = 0.1V (FBK = SHORT) VGN = 0.0V TPC 10. AC Response VGN (V) 1000 100 0.1 0.5 2.1 NOISE (nV/ Hz) TPC 13. Input Referred Noise vs. VGN Frequency (/H9024) 100 0.1 11 0 1 k 100 VGN = 2.9V RSOURCE ALONE NOISE (nV/ Hz) TPC 16. Input Referred Noise vs. RSOURCE VGN (V) VOS (V) 2.525 2.475 2.520 2.495 2.490 2.485 2.480 2.515 2.510 2.500 2.505 VOCM = 2.50V –40 C +25 C +85 C TPC 11. Output Offset vs. VGN TEMPERATURE ( C) 2.00 1.75 1.60–40 90–20 0 20 4 06 08 0 1.95 1.80 1.70 1.65 1.90 1.85 VGN = 2.9V NOISE (nV/ Hz) TPC 14. Input Referred Noise vs. Temperature RSOURCE (/H9024) NOISE FIGURE (dB) 11 0 1 k 100 VGN = 2.9V TPC 17. Noise TPC vs. R SOURCE VGN (V) 130 125 110 105 100 120 115 +85 C +25 C –40 C NOISE (nV/ Hz) TPC 12. Output Referred Noise vs. VGN FREQUENCY (Hz) 1.90 1.85 1.60 100k 1M 10M 1.80 1.75 1.70 1.65 VGN = 2.9V NOISE (nV/ Hz) TPC 15. Input Referred Noise vs. Frequency VGN (V) NOISE FIGURE (dB) RS = 50/H9024 TPC 18. Noise TPC vs. VGN

–6– REV. C FREQUENCY (Hz) HARMONIC DISTORTION (dBc) –30 –35 –70 100k 1M 100M 10M –50 –55 –65 –60 –40 –45 VO = 1V p-p VGN = 1.0V HD2 HD3 TPC 19. Harmonic Distortion vs. Frequency VGN (V) PIN (dBm) –20 –10 –15 FREQ = 10MHz FREQ = 1MHz INPUT GENERATOR LIMIT = 21 dBm TPC 22. 1 dB Compression vs. VGN 100ns / DIV 40mV / DIV VO = 200mV p-p VGN = 1.5V 200 –200 253ns 1.253/H9262s TRIG'D TPC 25. Small Signal Pulse Response VGN (V) HARMONIC DISTORTION (dBc) –35 –75 –55 –60 –65 –70 –40 –50 –45 HD3 (10MHz) HD2 (10MHz) HD2 (1MHz) HD3 (1MHz) TPC 20. Harmonic Distortion vs. VGN VGN (V) INTERCEPT (dBm) VO = 1V p-p f = 1MHz f = 10MHz TPC 23. Third Order Intercept vs. VGN VGN (V) 2.9V 0.0V 100 500mV 200ns500mV TPC 26. Power-Up/Down Response FREQUENCY (MHz) POUT (dBm) –20 –90 –120 9.92 9.96 10 10.02 10.04 –30 –80 –100 –110 –60 –70 –40 –50 f = 10MHz VO = 1V p-p VGN = 1.0V TPC 21. Intermodulation Distortion 100ns / DIV 400mV / DIV VO = 2V p-p VGN = 1.5V –2V 253ns 1.253/H9262s TPC 24. Large Signal Pulse Response VGN(V) 2.9V 0.1V 100 500mV 100ns500mV TPC 27. Gain Response

–7–REV. C FREQUENCY (Hz) CROSSTALK (dB) –30 –40 –90 100k 1M 100M 10M –50 –60 –80 –70 VGN1 = 1V VOUT1 = 1V p-p VIN2 = GND VGN2 = 2.9V VGN2 = 2.5V VGN2 = 2.0V VGN2 = 0.1V TPC 28. Crosstalk (CH1 to CH2) vs. Frequency TEMPERATURE ( C) SUPPLY CURRENT (mA) –40 90–20 0 20 40 60 80 +IS (AD605) +IS (VGN = 0) TPC 31. Supply Current (One Channel) vs. Temperature FREQUENCY (Hz) –10 –60 100k 1M 100M 10M –20 –30 –50 –40CMRR (dB) VIN = 0dBm VGN = 2.9V VGN = 2.5V VGN = 2.0V VGN = 0.1V TPC 29. Common-Mode Rejection vs. Frequency FREQUENCY (Hz) INPUT IMPEDANCE (/H9024) 180 175 140 100k 1M 100M 10M 160 155 145 150 170 165 VGN = 2.9V TPC 30. Input Impedance vs. Frequency FREQUENCY (Hz) 100k 1M 100M 10M DELAY (ns) VGN = 0.1V VGN = 2.9V TPC 32. Group Delay vs. Frequency

–12– REV. C C00541–0–7/04(C) 16-Lead Plastic Dual In-Line Package [PDIP] (N-16) Dimensions shown in inches and (millimeters) 1 8 0.295 (7.49) 0.285 (7.24) 0.275 (6.99) 0.100 (2.54) BSC SEATING PLANE 0.015 (0.38) MIN 0.180 (4.57) MAX 0.022 (0.56) 0.018 (0.46) 0.014 (0.36) 0.150 (3.81) 0.130 (3.30) 0.110 (2.79) 0.060 (1.52) 0.050 (1.27) 0.045 (1.14) 0.150 (3.81) 0.135 (3.43) 0.120 (3.05) 0.015 (0.38) 0.010 (0.25) 0.008 (0.20) 0.325 (8.26) 0.310 (7.87) 0.300 (7.62)CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN COMPLIANT TO JEDEC STANDARDS MO-095AC 0.785 (19.94) 0.765 (19.43) 0.745 (18.92) 16-Lead Standard Small Outline Package [SOIC] Narrow Body (R-16) Dimensions shown in millimeters and (inches) CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN COMPLIANT TO JEDEC STANDARDS MS-012AC 16 9 4.00 (0.1575) 3.80 (0.1496) 10.00 (0.3937) 9.80 (0.3858) 1.27 (0.0500) BSC 6.20 (0.2441) 5.80 (0.2283) SEATING PLANE 0.25 (0.0098) 0.10 (0.0039) 0.51 (0.0201) 0.31 (0.0122) 1.75 (0.0689) 1.35 (0.0531) 8/H11543 0/H11543 0.50 (0.0197) 0.25 (0.0098) 1.27 (0.0500) 0.40 (0.0157) COPLANARITY 0.10 /H11547 45/H11543 0.25 (0.0098) 0.17 (0.0067) OUTLINE DIMENSIONS

Revision History

7/04—Data Sheet Changed from REV. B to REV. C.