MAX2451

The monolithic MAX2451 is a quadrature demodulator with a supporting oscillator and divide-by-8 prescaler. It operates from a single +3V supply and draws only 5.5mA. The demodulator accepts an amplified and filtered IF signal in the 35MHz to 80MHz range, and demodulates it into I and Q baseband signals with 51dB of voltage conversion gain. The IF input is terminated with a 400 thin-film resistor for matching to an external IF filter. The baseband outputs are fully differential and have 1.2Vp-p signal swings.

Pulling the CMOS-compatible ENABLE pin low shuts down the MAX2451 and reduces the supply current to less than 2µA, typical. To minimize spurious feedback, the MAX2451's internal oscillator is set at twice the IF frequency via external tuning components. The MAX2451 comes in a 16-pin narrow SO package.