Analog Devices AD604 User Manual Page 1

Dual, Ultralow NoiseVariable Gain Amplifier AD604 Rev. E Information furnished by Analog Devices is believed to be accurate and reliable. However, n

AD604 Rev. E | Page 10 of 3–202 FREQUENCY (Hz)HARMONIC DISTORTION (dBc)–40–50–70–60–45–55–65100k 1M 10M 100MVO=1Vp-pVGN = 1VHD3HD200540-021Figure 21.

AD604 Rev. E | Page 11 of 32 100ns/DIV400mV/DIV2V–2V253ns 1.253µsVO=2Vp-pVGN = 1.5V00540-027Figure 27. Large Signal Pulse Response 100ns/DIV40mV/DIV

AD604 Rev. E | Page 12 of 32 FREQUENCY (Hz)1M1k1100k10k100101k 10k 100k 1M 10M 100MINPUT IMPEDANCE (Ω)00540-03325.8Figure 33. Input Impedance vs. Fre

AD604 Rev. E | Page 13 of 32 THEORY OF OPERATION The AD604 is a dual-channel VGA with an ultralow noise preamplifier. Figure 37 shows the simplified

AD604 Rev. E | Page 14 of 32 PREAMPLIFIER The input capability of the following single-supply DSX (2.5 ± 2 V for a +5 V supply) limits the maximum in

AD604 Rev. E | Page 15 of 32 121110A unique circuit technique is used to interpolate continuously among the tap points, thereby providing continuous

AD604 Rev. E | Page 16 of 32 GAIN CONTROL VOLTAGE (VGN)50–5AC COUPLING The DSX portion of the AD604 is a single-supply circuit and, therefore, its in

AD604 Rev. E | Page 17 of 32 The AFA offers the following additional features: • The ability to invert the signal by switching the positive and ne

AD604 Rev. E | Page 18 of 32 12APPLICATIONS INFORMATION The basic circuit in Figure 43 shows the connections for one channel of the AD604. The signal

AD604 Rev. E | Page 19 of 32 VG131615141918172423222120121110981234765AD604–5V+5VVREFRF OUT–5V+5V87651234AD711NCOUTAD835+5V–5V–5V+5V2VSET (<0V)–D

AD604 Rev. E | Page 2 of 32 TABLE OF CONTENTS Features ...

AD604 Rev. E | Page 20 of 32 The 50 Ω termination resistor, in parallel with the 50 Ω source resistance of the signal generator, forms an effective r

AD604 Rev. E | Page 21 of 3At 1 MHz, the attenuation is about −0.2 dB, increasing to −6 dB at 10 MHz and −28 dB at 100 MHz. Signals less than approx

AD604 Rev. E | Page 22 of 32 MEDICAL ULTRASOUND TGC DRIVING THE AD9050, A 10-BIT, 40 MSPS ADC The AD604 is an ideal candidate for the time gain contr

AD604 Rev. E | Page 23 of 32 131615141918172423222120121110981234765AD604+5V–5VIN1VREFOUT1VOCMVG1VG2OUT2NOTE 2NOTE 3NOTE 3IN2PAO2PAO1–DSX1+DSX1PAI1F

AD604 Rev. E | Page 24 of 3EVALUATION BOARD 2 Figure 55 is a photograph of the AD604 evaluation board assembly. Multiple input connections, test poin

AD604 Rev. E | Page 25 of 32 Connecting the DSX Inputs to the Preamplifiers To connect the DSX inputs to the preamplifiers, install jumpers in the J

AD604 Rev. E | Page 26 of 30-0572 EVALUATION BOARD ARTWORK AND SCHEMATIC 00540-059Figure 59. Internal Ground Plane 00540054Figure 57. Component Side

AD604 Rev. E | Page 27 of 32 R12–DSX1PAO1 OUT1VREFVGN1+DSX1154321131416171819201079865C80.1µFC90.1µFC70.1µFC140.1µFC130.1µFC20.1µFC40.1µFC60.1µF1211

AD604 Rev. E | Page 28 of 32 CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS(IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FORREFERENC

AD604 Rev. E | Page 29 of 32 COMPLIANT TO JEDEC STANDARDS MO-150-AG060106-A24131218.508.207.908.207.807.405.605.305.00SEATINGPLANE0.05 MIN0.65 BSC2.

AD604 Rev. E | Page 3 of 32 SPECIFICATIONS Each amplifier channel at TA = 25°C, VS = ±5 V, RS = 50 Ω, RL = 500 Ω, CL = 5 pF, VREF = 2.50 V (scaling

AD604 Rev. E | Page 30 of 32 NOTES www.BDTIC.com/ADI

AD604 Rev. E | Page 31 of 32 NOTES www.BDTIC.com/ADI

AD604 Rev. E | Page 32 of 32 NOTES ©1996–2008 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of

AD604 Rev. E | Page 4 of 32 Parameter Conditions Min Typ Max Unit ACCURACY Absolute Gain Error 0 dB to 3 dB 0.25 V

AD604 Rev. E | Page 5 of 32 ABSOLUTE MAXIMUM RATINGS Table 2. Parameter1, 2Rating Supply Voltage ±VS Pin 17 to Pin 20 (with Pin 16, Pin 22 = 0 V)

AD604 Rev. E | Page 6 of 32 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS –DSX11+DSX1 2PAO1 3FBK14VGN124VREF23OUT122GND121PAI1 5COM1 6COM27VPOS20VNEG1

AD604 Rev. E | Page 7 of 32VGN (V)–10 TYPICAL PERFORMANCE CHARACTERISTICS Unless otherwise noted, G (preamplifier) = 14 dB, VREF = 2.5 V (20 dB/V sc

AD604 Rev. E | Page 8 of 32 VGN (V)GAIN ERROR (dB)2.01.51.00.50–0.5–1.0–1.5–2.0FREQUENCY (Hz)GAIN (dB)5040–503020100–10–20–30–40100k 1M 10M 100M0.2 0

AD604 Rev. E | Page 9 of 32100010.11010.1VGN = 2.9V VGN (V)10010NOISE (nV/ Hz)0.1 0.5 0.9 1.3 1.7 2.1 2.5 2.900540-015Figure 15. Input Referred Nois