GENERAL DESCRIPTION

The AD9874 is a general-purpose IF subsystem that digitizes a low level 10 MHz to 300 MHz IF input with a signal bandwidth ranging from 6.8 kHz to 270 kHz. The signal chain of the AD9874 consists of a low noise amplifier, a mixer, a band-pass sigma-delta analog-to-digital converter, and a decimation filter with programmable decimation factor. An automatic gain control (AGC) circuit gives the AD9874 12 dB of continuous gain adjustment. Auxiliary blocks include both clock and LO synthesizers.

FEATURES

  10 MHz to 300 MHz Input Frequency

  7.2 kHz to 270 kHz Output Signal Bandwidth

  8.1 dB SSB NF

  0 dBm IIP3

  AGC Free Range up to –34 dBm

  12 dB Continuous AGC Range

  16 dB Front End Attenuator

  Baseband I/Q 16-Bit (or 24-Bit) Serial Digital Output

  LO and Sampling Clock Synthesizers

  Programmable Decimation Factor, Output Format, AGC, and Synthesizer Settings

  370 Ω Input Impedance

  2.7 V to 3.6 V Supply Voltage

  Low Current Consumption: 20 mA

  48-Lead LQFP Package (1.4 mm Thick)

APPLICATIONS

  Multimode Narrow-Band Radio Products

     Analog/Digital UHF/VHF FDMA Receivers

     TETRA, APCO25, GSM/EDGE

  Portable and Mobile Radio Products

  Base Station Applications

  SATCOM Terminals