U4285BM

U4285BM AM / FM - PLL Description The U4285BM is an integrated circuit in BICMOS technology for frequency synthesizers. It performs all the functions of a PLL radio tuning system and is controlled by an I2C bus. The device is designed for all frequency synthesizer applications in radio receivers, as well as RDS ( Radio Data System ) applications. Features D Reference oscillator up to 15 MHz D Two programmable 16 bit dividers adjustable from 2 to 65535 D 4 programmable switching outputs (open drain up to 15 V) D Fine tuning steps: AM FM y 1 kHz y 2 kHz D Few external component required due to integrated loop-push-pull stage for AM/FM D High signal/ noise ratio Ordering Information Extended Type Number U4285BM-AFS U4285BM-AFSG3 Package SSO20 plastic SSO20 plastic Remarks Taping according to IEC-286-3 Block Diagram SWO1 SWO2 SWO3 SWO4 5 6 7 8 OSCIN 18 Oscillator OSCOUT 19 SCL 2 I2C bus interface Phase detector Current sources 15 16 17 12 13 N-divider 1 VDD Figure 1. 20 GND1 PDAMO VA C PDFMO PDFM R-divider Switching outputs 14 PDAM SDA 3 AS FMOSC 4 9 AMOSC 11 AM/FM switch 10 GND2 95 10120 TELEFUNKEN Semiconductors Rev. A3, 14-May-97 1 (10) U4285BM Pin Description VDD SCL 1 2 3 4 5 20 19 18 17 16 GND1 OSCOUT OSCIN C VA PDAMO PDAM PDFM PDFMO AMOSC Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Symbol VDD SCL SDA AS SWO 1 SWO 2 SWO3 SWO4 FMOSC GND 2 AMOSC PDFMO PDFM PDAM PDAMO VA C OSCIN OSCOUT GND1 Function Supply voltage I2C bus clock I2C bus data Address se...