AD8334 Quad VGA with Ultralow Noise Preamplifier and Programmable RIN

The AD8334 is an ultralow noise, quad channel linear-in-dB variable gain amplifier (VGA). Although optimized for ultrasound systems, it may be used as a low noise variable gain control in any application whose operating frequency is less than 100 MHz.

Included in each channel are an ultralow noise preamp (LNA), an X-AMP® VGA with 48 dB of gain range, and a selectable gain postamp with adjustable output limiting. The LNA gain is 19 dB with a single-ended input and differential outputs. Using a single resistor, the LNA input impedance can be adjusted to match a signal source without compromising noise performance.

The 48 dB gain range of the VGA makes these devices suitable for a variety of applications. Excellent bandwidth uniformity is maintained across the entire range. The gain control interface provides precise linear-in-dB scaling of 50 dB/V for control voltages between 40 mV and 1 V. Factory trim ensures excellent part-to-part and channel-to-channel gain matching. Differential signal paths result in superb second- and third-order distortion performance and low crosstalk.

The AD8334 is a quad version of the single AD8331 and dual AD8332.

For information on specs, see the AD8331/AD8332/AD8334 datasheet.

Applications
  • Ultrasound and sonar time-gain controls
  • High performance automatic gain control (AGC) systems
  • I/Q signal processing
  • High speed, dual ADC drivers
Features and Benefits
  • Ultralow noise preamplifier (preamp)
    • Voltage noise = 0.74 nV/√Hz
    • Current noise = 2.5 pA/√Hz
  • Voltage noise = 0.74 nV/√Hz
  • Current noise = 2.5 pA/√Hz
  • 3 dB bandwidth: 100 MHz
  • Low power: 145 mW/channel
  • Wide gain range with programmable postamp
    • −4.5 dB to +43.5 dB in LO gain mode
    • 7.5 dB to 55.5 dB in HI gain mode
  • −4.5 dB to +43.5 dB in LO gain mode
  • 7.5 dB to 55.5 dB in HI gain mode
  • Low output-referred noise: 48 nV/√Hz typical
  • Active input impedance matching
  • Optimized for 10-bit/12-bit ADCs
  • Selectable output clamping level
  • Single 5 V supply operation
  • AD8332 and AD8334 available in lead frame chip scale package
  • Amplifiers
    Data Sheets
    Documentnote
    AD8331/AD8332/AD8334: Ultralow Noise VGAs with Preamplifier and Programmable RIN Data Sheet (Rev. I)PDF 1.91 M
    Frequently Asked Questions
    Documentnote
    Order Information
    Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
    AD8334ACPZ Production64 ld LFCSP (9x9mm, 4.70mm exposed pad)OTH 260-40 to 85C18.1714.66Y
    AD8334ACPZ-REEL Production64 ld LFCSP (9x9mm, 4.70mm exposed pad)REEL 2500-40 to 85C014.66Y
    AD8334ACPZ-REEL7 Production64 ld LFCSP (9x9mm, 4.70mm exposed pad)REEL 750-40 to 85C18.1714.66Y
    Evaluation Boards
    Part NumberDescriptionPriceRoHS
    AD8334-EVALZEvaluation Board294.19Y
    Reference Materials
    Datasheet
    AD8331/AD8332/AD8334: Ultralow Noise VGAs with Preamplifier and Programmable RIN Data Sheet (Rev. I) ad8332
    AD8331/AD8332/AD8334:带前置放大器和可编程输入电阻(RIN)的超低噪声VGA (Rev. G) ad8332
    Other
    Design and Operation of Automatic Gain Control Loops for Receivers in Modern... ad8369
    Ultrasound System Considerations and their Impact on Front-End Components ad600
    Variable Gain Amplifier Selection Table ad8369