TR5100

The TR5100 is a low power FM transceiver IC consisting of a receiver and a transmitter on a single chip. The receiver down converts an RF FM signal through an off-chip filter to IF frequency and then performs quadrature demodulation. IF filtering is performed by an off-chip filter. A speaker amplifier TR5100 provides the capability of driving an off-chip class AB output stage which feeds audio signal to an external speaker. In addition, it allows the user to adjust speaker gain through a feedback function. A MUTE output of TR5100 is provided such that an RSSI current may be externally low-passed to provide a mute/disable function to the receiver audio in case of a weak received signal.

Receiving an audio input from a microphone, the transmitter TR5100 amplifies and performs FM modulation onto a Colpitts oscillator output by way of a variable reactance circuit. The frequency of the signal is then up converted by an on-chip trippler to three times high as the RF output. The output is then sent to an antenna through an off-chip filter. A build-in feedback function in the microphone amplifier allows adjustment of its gain. In addition, an oscillation function is featured to enable paging of its transceiver mate by way of an external switch.

The frequency range of the TR5100 radio frequencies is from 15MHz to 150MH. It may by supported by simply choosing the appropriate external components. The transmitter and receiver oscillators require 2 crystals to clamp the TX and RX frequencies.