HD74HC4543 Datasheet | Hitachi Semiconductor

BCD-to-Seven Segment Latch/Decoder/Driver Description This circuit contains a 4-bit latch, BCD-to-7 segment decoder, and 7 outpt drivers. Data on the input pins flow through to the output when the Latch Disable (LE) is high and is latched on the high to low transition of the LE input. The Phase input (Ph) controls the polarity of the 7 segment outputs. when Ph is low the outputs are true 7 segment, and when Ph is high the outputs are inverted 7 segment. When the Phase input is driven by a liquid crystal display (LCD) backplane waveform the segment pins output the correct segment waveform for proper LCD AC drive voltages. In addition a Blanking input (BI) is provided, which will blank the display. Features - - - - - High Speed Operation: tpd (A, B, C, D to a - g) = 33 ns typ (CL = 50 p F) High Output Current: Fanout of 10 LSTTL Loads Wide Operating Voltage: VCC = 2 to 6 V Low Input Current: 1 µA max Low Quiescent Supply Current: ICC (static) = 4 µA max (Ta = 25°C) Function Table Inputs LD X H H H H H H H H H H H H H H H H L BI H L L L L L L L L L L L L L L L L L Ph- L L L L L L L L L L L L L L L L L L Outputs D X L L L L L L L L H H H H H H H H X C X L L L L H H H H L L L L H H H H X B X L L H H L L H H L L H H L L H H X A X L H L H L H L H L H L H L H L H X a L H L H H L H H H H H L L L L L L - 2 b L H H H H H L L H H H L L L L L L c L H H L H H H H H H H L L L L L L d L H L H H L H H L H H L L L L L L e L H L H L L L H L H L L L L L L L f L H L L L H H H L H H L L L L L L g L L L H H H H H L H H L L L L L L Display Blank 0 1 2 3 4 5 6 7 8 9 Blank Blank Blank Blank Blank Blank - 1 Notes: 1. For liquid crystal readouts, apply a square wave to Ph. For mon cathode LED readouts, select Ph = L. For mon anode LED readouts, select Ph = H 2. Depends upon the BCD coder previously applied when LD = H a f e d g c b Pin Arrangement Latch Disable C B D A Phase Blanking GND 1 2 3 4 5 6 7 8 (Top view) C B D A Ph Bl LD f g...