Analog Devices AD604 manuals

32 pages817.72 Kb

Dual, Ultralow Noise Variable Gain Amplifier
- FEATURES
- APPLICATIONS
- FUNCTIONAL BLOCK DIAGRAM
- GENERAL DESCRIPTION
- 2AD604
- TABLE OF CONTENTS
- 3 AD604
- SPECIFICATIONS
- 4AD604
- 5 AD604
- ABSOLUTE MAXIMUM RATINGS
  - ESD CAUTION
- 6AD604
- PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
  - Table 3. Pin Function Descriptions
- 7 AD604
  - Figure 8. Gain Error vs. VGN at Different Frequencies
  - Figure 5. Gain vs. VGN for Different Gain Scalings
    - GAIN SCALING (dB/V)
- TYPICAL PERFORMANCE CHARACTERISTICS
  - GAIN (dB)
  - Figure 3. Gain vs. VGN for Three Temperatures
  - Figure 4. Gain vs. VGN for Different Preamplifier Gains
  - Figure 6. Gain Scaling vs. VREF
  - Figure 7. Gain Error vs. VGN
  - 8
  - Figure 9. Gain Error vs. VGN for Two Gain Scaling Values
  - Figure 14. Output Referred Noise vs. VGN for Three Temperatures
  - Figure 11. Gain Match; VGN1 = VGN2 = 2.50 V
    - PERCENTAGE
  - Figure 10. Gain Match; VGN1 = VGN2 = 1.0 V
  - Figure 12. AC Response for Various Values of VGN
    - (V)
  - Figure 13. Output Offset vs. VGN for Three Temperatures
    - NOISE (nV/ Hz)
  - 9
  - Figure 15. Input Referred Noise vs. VGN
  - Figure 20. Noise Figure vs. VGN
    - 00.40.81.21.62.02.42.8
    - 0
    - VGN(V)
    - 20
  - Figure 17. Input Referred Noise vs. Frequency
  - Figure 16. Input Referred Noise vs. Temperature
  - Figure 18. Input Referred Noise vs. RSOURCE
    - 40
  - Figure 19. Noise Figure vs. RSOURCE
    - R
    - =240
    - 35 30 25 15 10 5
  - 10
    - 2
    - Rev. E | Page 10 of 3
  - Figure 21. Harmonic Distortion vs. Frequency
  - Figure 26. Third-Order Intercept vs. VGN
    - f
  - Figure 23. Harmonic Distortion vs. RSOURCE
  - Figure 22. Harmonic Distortion vs. VGN
  - Figure 24. Intermodulation Distortion
  - Figure 25. 1 dB Compression vs. VGN
  - 11
    - 100ns/DIV
  - Figure 32. DSX Common-Mode Rejection Ratio vs. Frequency
    - CROSSTALK (dB)
      - 100ns/DIV
        400mV/DI
      - 2
      - 2V 253ns 1.253s
      - =2Vp-p VGN= 1.5V
  - Figure 27. Large Signal Pulse Response
    - 40mV/DI
    - 200
    - 200 253ns 1.253s
    - =200mVp-p VGN= 1.5V
    - TRIG'D
  - Figure 28. Small Signal Pulse Response
    - VGN (V)
  - Figure 29. Power-Up/Power-Down Response
    - VGN (V)
  - Figure 30. Gain Response
    - CMRR (dB)
  - Figure 31. Crosstalk (Channel 1 to Channel 2) vs. Frequency
  - 12
    - INPUT IMPEDANCE ()
    - DELAY (ns)
  - Figure 34. Input Bias Current vs. Temperature
    - SUPPLY CURRENT (mA)
  - Figure 33. Input Impedance vs. Frequency
    - INPUT BIAS CURRENT (A)
  - Figure 35. Supply Current (One Channel) vs. Temperature
  - Figure 36. Group Delay vs. Frequency
- 13 AD604
- THEORY OF OPERATION
  - PREAMPLIFIER
  - 14()
    - ()
    - []
      - ()
        15DIFFERENTIAL LADDER (ATTENUATOR)
        16AC COUPLING
        GAIN CONTROL INTERFACE
        ACTIVE FEEDBACK AMPLIFIER (FIXED-GAIN AMP)
- 18AD604
- APPLICATIONS INFORMATION
  - 19ULTRALOW NOISE AGC AMPLIFIER WITH 82 dB TO 96 dB GAIN RANGE
    - - Rev. E | Page 21 of 3
    - 500mV
    - 100 90 80 70 60 50 40 30 20 10 0 10
    - (dBm)
    - CONTROL VOLTAGE (V)
      - 1.0
      - 0
    - GND1
    - FBK1
    - FB
    - 2
    - AD604
      - DSX1 +DSX1 PAI1
      - PAO1 COM1 COM2 PAI2 FBK2 PAO2 +DSX2 DSX2
      - VGN1 VREF VPOS
      - OUT1 VNEG VNEG VPOS GND2 OUT2 VOCM VGN2
      - C5 0.1F
      - R2 499
      - C6 560pF C3 0.1F FAIR-RITE #2643000301
      - Figure 48. Modifications of the AGC Amplifier to Create 96 dB of Gain Range
        4.5 4.0
        3.5 3.0
        2.5 2.0 1.5
        1MHz
        0.5 P
      - Figure 49. Control Voltage vs. Input Power of the Circuit in Figure 48
  - 21ULTRALOW NOISE, DIFFERENTIAL INPUT- DIFFERENTIAL OUTPUT VGA
    - the signal amplitude compared with when they are driven single-ended.
      - AD604
      - Figure 50. Ultralow Noise, Differential Input-Differential Output VGA
    - 20ns20mV
    - 20mV NOTES 1.THE OUTP UT AFTER 10 ATTENUATER FORME D BY453TOGETHER WITH 50 OF 7A24 PLUG-IN.
    - ACTUAL V
    - +500mV
    - Figure 51. Output of VGA in Figure 50 for VGN = 1 V
  - 22MEDICAL ULTRASOUND TGC DRIVING THE AD9050, A 10-BIT, 40 MSPS ADC
    - AD604
    - AD9050
    - AD7226
    - AD9631
    - Figure 52. TGC Circuit for Medical Ultrasound Application
    - - 23AD604
        Figure 53. Basic Test Board
        AD604
        Figure 54. Setup for Gain Measurements
- 24AD604
- EVALUATION BOARD
  - DSX INPUT CONNECTIONS
    - Differential DSX Inputs
  - USING THE PREAMPLIFIER
    - Connecting the DSX Inputs to the Preamplifiers
    - Cascaded DSX
  - 25PREAMPLIFIER GAIN
  - OUTPUTS
  - DC OPERATING CONDITIONS
  - 26EVALUATION BOARD ARTWORK AND SCHEMATIC
    - AD604
      - Figure 61. Evaluation Board Schematic
    - 27Table 6. Bill of Materials
      - 40 MHz dual low noise VGA
- 28AD604
- OUTLINE DIMENSIONS
  - 29ORDERING GUIDE