U4256BM-R Datasheet, PDF (1/19 Pages) ATMEL Corporation – Frequency Synthesizer for Radio Tuning

Features
• Reference Oscillator up to 15 MHz (Tuned)
• Oscillator Buffer Output (for AM Up/Down Conversion)
• Two Programmable 16-bit Dividers
• Fine-tuning Steps Possible
• Fast Response Time due to Integrated Loop Push-pull Stage
• 3-wire Bus (Enable, Clock and Data; 3 V and 5 V Microcontrollers Acceptable)
• Four Programmable Switching Outputs (Open Drain)
• Three DACs for Software Controlled Tuner Alignment
• Low-power Consumption
• High S/N Ratio
• Integrated Band Gap – only One Supply Voltage Necessary
Description
The U4256BM-R is a synthesizer IC for FM receivers and an AM up-convertion
system in BICMOS technology. Together with the AM/FM IC T4258 or U4255BM, it
performs a complete AM/FM car radio front-end, which is recommended also for RDS
(Radio Data System) applications. It is controlled by a 3-wire bus and also contains
switches and Digital to Analog Converters (DACs) for software-controlled alignment of
the AM/FM tuner. The U4256BM-R is the pin-compatible succesor IC of U4256BM-N.
Pin Configuration
Figure 1. Pinning SSO20
Frequency
Synthesizer for
Radio Tuning
U4256BM-R
Preliminary
Rev. 4562C–AUDR–08/04
1