DESCRIPTION

The M491B is a monolithic N-MOS LSI circuit including a Floating-gate Non-Volatile Memory for storage of up to 16 stations. Tuning of the station is performed with a 8192 step D/A converter, using the principle of voltage synthesis. It is designed for 7-segment LED displays. Direct memory selection is possible only from remote control while Up/Down memory scanning is possible on the set and also from remote control. An option input for 8 or 16 stations is available. The circuit also includes a PCM remote control receiver operating in conjunction with the transmitter M708.

■ 16-STATION MEMORY - 7-SEGMENT LED DISPLAY

■ VOLTAGE SYNTHESIZER : 13 BITS

■ 4-BAND PRESET CAPABILITY

■ NON-VOLATILE MEMORY : 304 BITS

- 16 WORDS OF 19 BITS FOR TUNING VOLTAGE (13 bits) - BAND (2 bits) - FINE DETUNING (4 bits)

- 104 MODIFY CYCLES PER WORD

- MIN 10 YEARS DATA RETENTION

■ PCM REMOTE CONTROL RECEIVER : DECODES SIGNAL TRANSMITTED BY M708

■ VOLUME D/A : 6-BIT RESOLUTION / 8kHz

■ MEMORY SKIP FUNCTION

■ AUTOMATIC SEARCH WITH DIGITAL AFT CONTROL

■ FINE DETUNING D/A ACTING ON AFT DISCRIMINATOR (16 steps) WITH SEPARATE STORAGE FOR EACH MEMORY POSITION.

ALTERNATIVELY IT CAN BE USED TO CONTROL BRIGHTNESS OR COLOUR SATURATION

■ MANUAL SEARCH WITH DIGITAL AFT CONTROL

■ MANUAL SEARCH WITH LINEAR AFT

■ SWEEP SEARCH DISPLAY OUTPUT

■ SUPPLY VOLTAGES : VDD = + 5V, VPP = + 25V FOR THE MEMORY

■ CLOCK OSCILLATOR : 445 TO 510kHz

■ INTEGRATED DIGITAL POWER ON RESET

(no external initialization circuitry required)