UPD16431A Datasheet | NEC

DATA SHEET MOS INTEGRATED CIRCUIT µPD16431A 1/2, 1/3, 1/4-DUTY LCD CONTROLLER/DRIVER The µPD16431A is an LCD controller/driver that enables display of segment type LCDs of 1/2, 1/3, or 1/4 duty cycle. This controller/driver has 56 segment output lines of which eight can also be used as LED output lines. Because the LCD driver contained in the µPD16431A has separate logic and power supply, up to 6.5 V of LCD drive voltage can be set. In addition, key source output lines for key scanning and key input data lines are also provided, so that the µPD16431A is ideal for applications in the front panel of an automobile stereo system. Features - Various display modes 1/2 duty: 112 segment outputs or 96 segment outputs + 8 LED outputs 1/3 duty: 168 segment outputs or 144 segment outputs + 8 LED outputs 1/4 duty: 224 segment outputs or 192 segment outputs + 8 LED outputs - Key scan circuit (key source outputs are shared with LCD driver outputs) - Independent LCD driver power supply VLCD (can be set to VDD to 6.5 V) - Serial data input/output (SCK, STB, DATA) - On-chip oscillator incorporated - Power-ON reset circuit ORDERING INFORMATION Part Number Package 80-pin plastic QFP (0.65 pitch, 14 × 14) µPD16431AGC-7ET Document No. IC-3414 (O.D. No. IC-8885) Date Published January 1995 P Printed in Japan © µPD16431A BLOCK DIAGRAM S48 S49/LED1 S56/LED8 S1/KS1 S1/KS2 S8/KS8 48 8 Segment driver 56 Level shifter (56) 56 Key counter Selector circuit 56 Write address STB 56 DATA CLK I/O control 56-bit shift register Output latch (56 × 4) 2 OE 8 LED driver mon driver 4 Level shifter 4 OE LCD/LED SYNC Timing generator Read address OSC OSCIN OSCOUT 8-bit shift register 8 KEY REQ mand decoder key1 Key counter Key latch S/R...