1. Introduction
The SA58640 was designed for cordless telephone applications in which efficient and
economic integrated solutions are required and yet high performance is desirable.
Although the product is not targeted to meet the stringent specifications of high
performance cellular equipment, it will exceed the needs for analog cordless phones. The
minimal amount of external components and absence of any external adjustments makes
for a very economical solution.
2. General description
The SA58640 is a low-voltage monolithic FM IF system incorporating a mixer/oscillator,
two limiting intermediate frequency amplifiers, quadrature detector, logarithmic RSSI,
voltage regulator and audio and RSSI operational amplifiers. The SA58640 is available in
a 20-pin SSOP package.
3. Features and benefits
Low power consumption: 5.0 mA typical at 5 V
Mixer input to >100 MHz
Mixer conversion power gain of 17 dB at 45 MHz
Crystal oscillator effective to 100 MHz (LC oscillator or external oscillator can be used
at higher frequencies)
102 dB of IF amplifier/limiter gain
2 MHz IF amplifier/limiter small signal bandwidth
Temperature compensated logarithmic RSSI with a 70 dB dynamic range
Low external component count; suitable for crystal/ceramic/LC filters
Audio output internal op amp
RSSI output internal op amp
Internal op amps with rail-to-rail outputs
ESD protection: Human body model 2 kV; robot model 200 V
4. Applications
Cordless telephones
SA58640
Low-voltage mixer FM IF system
Rev. 3 — 12 April 2011 Product data sheet
