3848中文資料ALLEGRO數(shù)據(jù)手冊PDF規(guī)格書

DUAL-CONVERSION AM RECEIVER

Providing the AM signal processing functions for an electronically tuned AM receiver (ETR), the A3848EEQ includes two balanced mixers, a crystal local oscillator, an L/C-tuned local oscillator, oscillator buffer, IF amplifier, AM detector, scan control detectors, and a switchable voltage regulator. This dual-conversion device typically mixes the incoming RF up to a first IF of 10.7 MHz, then down to 450 kHz, and then detects the audio. The addition of a JFET matched to a whip antenna, RF low-pass filter, IF selectivity, and audio stages gives a complete AM radio which can be used in automotive receivers. The frequency-detecting stop circuit is also capable of recovering narrowband FM, making it useful for scanners or weather band radio applications. Two AGC and field-strength indicator modes provide special features for scanning.

FEATURES

■ Low Noise Figure

■ Field-Strength Indicator

■ Balanced Mixers

■ Buffered Oscillator

■ High Dynamic Range First Mixer

■ Fast Scan Mode