IF Digitizing Subsystem AD9874*
FEATURES 10 MHz to 300 MHz Input Frequency 7.2 kHz to 270 kHz Output Signal Bandwidth 8....
IF Digitizing Subsystem AD9874*
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 ⍀ 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 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. The AD9874’s high dynamic range and inherent antialiasing provided by the band-pass sigma-delta converter allow the AD9874 to cope with blocking signals up to 95 dB stronger than the desired signal. This attribute can often reduce the cost of a radio by reducing its IF filtering re...
