Low Power Narrowband FM IF

The MC3371 and MC3372 perform single conversion FM reception and consist of an oscillator, mixer, limiting IF amplifier, quadrature discriminator, active filter, squelch switch, and meter drive circuitry. These devices are designed for use in FM dual conversion communication equipment. The MC3371/MC3372 are similar to the MC3361/MC3357 FM IFs, except that a signal strength indicator replaces the scan function controlling driver which is in the MC3361/MC3357. The MC3371 is designed for the use of parallel LC components, while the MC3372 is designed for use with either a 455 kHz ceramic discriminator, or parallel LC components.

These devices also require fewer external parts than earlier products. The MC3371 and MC3372 are available in dual–in–line and surface mount packaging.

• Wide Operating Supply Voltage Range: VCC = 2.0 to 9.0 V

• Input Limiting Voltage Sensitivity of –3.0 dB

• Low Drain Current: ICC = 3.2 mA, @ VCC = 4.0 V, Squelch Off

• Minimal Drain Current Increase When Squelched

• Signal Strength Indicator: 60 dB Dynamic Range

• Mixer Operating Frequency Up to 100 MHz

• Fewer External Parts Required than Earlier Devices