AD8432 Dual-Channel Ultralow Noise Amplifier with Selectable Gain and Input Impedance

The AD8432 is a dual-channel, low power, ultralow noise amplifier with selectable gain and active impedance matching. Each channel has a single-ended input, differential output, and integrated input clamps. By pin strapping the gain setting pins, four accurate gains of G = 12.04 dB, 18.06 dB, 21.58 dB, and 24.08 dB (×4, ×8, ×12, and ×16, respectively) are possible. A bandwidth of 200 MHz at G = 12.04 dB makes this amplifier well suited for many high speed applications.

The exceptional noise performance of the AD8432 is made possible by the active impedance matching. Using a feedback network, the input impedance of the amplifiers can be adjusted to match the signal source impedance without compromising the noise performance. Impedance matching and low noise in the AD8432 allow designers to create wider dynamic range systems that are able to detect even very low level signals.

The AD8432 achieves 0.85 nV/√Hz input-referred voltage noise for a gain of 12.04 dB. The AD8432’s ultralow noise, low distortion, gain accuracy, and channel-to-channel matching are ideal for high performance ultrasound systems and for processing I/Q demodulator signals.

The AD8432 operates on a single supply of 5 V at 24 mA. It is available in a 4 mm × 4 mm, 24-lead LFSCP. The LFCSP features an exposed paddle that provides a low thermal resistance path to the PCB, which enables more efficient heat transfer and increases reliability. The operating temperature range is −40°C to +85°C.

Applications
  • CW Doppler ultrasound front ends
  • Low noise preamplification
  • Predriver for I/Q demodulators and phase shifters
  • Wideband analog-to-digital drivers
Features and Benefits
  • Low noise
    Input voltage noise: 0.85 nV/√Hz
    Current noise: 2.0 pA/√Hz
  • High speed
    200 MHz bandwidth (G = 12.04 dB)
    295 V/μs slew rate
  • Selectable gain
      G = 12.04 dB (×4)
      G = 18.06 dB (×8)
      G = 21.58 dB (×12)
      G = 24.08 dB (×16)
  • Active input impedance matching
  • Integrated input clamp diodes
  • Single-ended input, differential output
  • Supply range: 4.5 V to 5.5 V
  • Low power: 60 mW/channel
  • Amplifiers
    RF & Microwave
    Data Sheets
    Documentnote
    AD8432: Dual-Channel Ultralow Noise Amplifier with Selectable Gain and Input Impedance Data Sheet (Rev. C)PDF 190 kB
    Order Information
    Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
    AD8432ACPZ-R7 Production24 ld LFCSP 4x4mm (2.5EP) REEL 1500-40 to 85C1.61.29Y
    AD8432ACPZ-RL Last Time Buy24 ld LFCSP 4x4mm (2.5EP) REEL 5000-40 to 85C1.61.29Y
    AD8432ACPZ-WP Production24 ld LFCSP 4x4mm (2.5EP) REEL 64-40 to 85C1.61.29Y
    Evaluation Boards
    Part NumberDescriptionPriceRoHS
    AD8432-EVALZEvaluation Board125Y
    AD8432: Dual-Channel Ultralow Noise Amplifier with Selectable Gain and Input Impedance Data Sheet (Rev C, 07/2012) AD8432
    AD8432: Dual-Channel Ultralow Noise Amplifier with Selectable Gain and Input Impedance Data Sheet (Rev. C) ad8432