ATR4256-TKQY

ATR4256-TKQY Features

• Reference Oscillator up to 15 MHz (Tuned)(cid:127) Oscillator Buffer Output (for AM Up/Down Conversion)(cid:127) Two Programmable 16-bit Dividers(cid:127) Fine-tuning Steps Possible(cid:127) Fast Response Time Due to Integrated Loop Push-pull Stage(cid:127) 3-wire Bus (Enable, Clock and Data; 3V and 5V Microcontrollers Acceptable)(cid:127) Four Programmable Switching Outputs (Open Drain)(cid:127) Three DACs for Software Controlled Tuner Alignment(cid:127) Low-power Consumption(cid:127) High Signal to Noise Ratio (SNR)Integrated Band Gap – Only One Supply Voltage Necessary

ATR4256-TKQY 1. Description

The ATR4256 is a synthesizer IC for FM receivers and an AM up-conversion systemin BiCMOS technology. Together with the AM/FM IC ATR4258 or ATR4255, it com-prises a complete AM/FM car radio front-end, which is also recommended for RDS(Radio Data System) applications. It is controlled by a 3-wire bus and also containsswitches and Digital to Analog Converters (DACs) for software-controlled alignment ofthe AM/FM tuner. The ATR4256 is the pin-compatible successor IC of U4256BM-R.Figure 1-1.Block DiagramTuningSWO1 SWO2 SWO3 SWO478910OSCINOSCOUTMX2LOCLKDATAEN131215171618OscillatorSwitching outputsOSCbuffer3-wirebusinterfaceDAC33-bitVRefDAC2DAC1R-dividerDACAM/FMVRefFMOSCIN19FM-preampN-dividerPhasedetectorCurrentsources20GNDANBand gap14V5116GNDVS54312DAC3DAC2DAC1PDOPD

ATR4256-TKQY 3. Functional Description

For a tuned FM-broadcast receiver, the following parts are needed: