[Melexis]

General Description

The TH71101 receiver IC consists of the following building blocks

? PLL synthesizer (PLL SYNTH) for generation of the local oscillator signal LO

? Parts of the PLL SYNTH are the high-frequency VCO1, the feedback divider DIV_16, a phase-frequency detector (PFD) with charge pump (CP) and a crystal-based reference oscillator (RO)

? Low-noise amplifier (LNA) for high-sensitivity RF signal reception

? First mixer (MIX1) for down-conversion of the RF signal to the IF

? IF pre amplifier which is a mixer cell (MIX2) that operates as an amplifier

? IF amplifier (IFA) to amplify and limit the IF signal and for RSSI generation

? Phase coincidence demodulator (DEMOD) with third mixer (MIX3) to demodulate the IF signal

? Operational amplifier (OA) for data slicing, filtering and ASK detection

? Bias circuitry for bandgap biasing and circuit shutdown

特性 Features

? Single superhet architecture for low external component count

? FSK for digital data and FM reception for analog signal transmission

? FM/FSK demodulation with phase-coincidence demodulator

? Low current consumption in active mode and very low standby current

? Switchable LNA gain for improved dynamic range

? RSSI allows signal strength indication and ASK detection

? Surface mount package LQFP32

Application Examples

? General digital and analog 315 MHz or 433 MHz ISM band usage

? Low-power telemetry

? Alarm and security systems

? Keyless car and central locking

? Pagers