MAX2172
Direct-Conversion to Low-IF Tuner for Digital Audio
Broadcast
High-Performance Digital Radio Tuner Incorporates Fast and Accurate RSSI Function
OVERVIEW
Description
The MAX2172 direct-conversion to low-IF tuner is designed for digital
audio broadcast (DAB) and terrestrial digital multimedia broadcast (T-
DMB) applications, covering an input frequency range of 168MHz to
240MHz (VHF-III), 1452MHz to 1492MHz (L-band), and also 87MHz
to 108MHz (FM). The MAX2172 achieves a high level of component
integration, allowing lowpower, tuner-on-board designs. The direct-
conversion to low-IF architecture eliminates the need for an IF-SAW
filter while providing a balanced 2.048MHz center frequency
baseband output to the demodulator.
The MAX2172 provides a buffered reference clock at the crystal
frequency.
A sigma-delta fractional-N synthesizer is incorporated to optimize
both close-in and wideband phase noise performances for OFDM
applications where sensitivity to both 1kHz phase noise and
wideband phase noise related to strong adjacents can be a problem.
The MAX2172 is available in a 40-pin thin QFN package (6mm x
6mm) with an exposed pad. Electrical performance is guaranteed
over the extended -40°C to +85°C temperature range.
MAX2172: Functional Diagram
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