DS8880 Datasheet | National Semiconductor

Description The DS7880 DS8880 is custom designed to decode four lines of BCD and drive a gas-filled seven-segment display tube Each output constitutes a switchable adjustable current sink which provides constant current to the tube segment even with high tube anode supply tolerance or fluctuation These current sinks have a voltage pliance from 3V to at least 80V typically the output current varies 1% for output voltage changes of 3 to 50V Each bit line of the decoder switches a current sink on or off as prescribed by the input code Each current sink is ratioed to the b-output current as required for even illumination of all segments Output currents may be varied over the 0 2 to 1 5 m A range for driving various tube types or multiplex operation The output current is adjusted by connecting an external pro- gram resistor (RP) from VCC to the Program input in accordance with the programming curve The circuit design provides a one-to-one correlation between program input current and b-segment output current The Blanking Input provides unconditional blanking of any output display while the Ripple Blanking pins allow simple leading- or trailing-zero blanking Features Y Current sink outputs Y Adjustable output current 0 2 to 1 5 m A Y High output breakdown voltage 110V typ Y Suitable for multiplex operation Y Blanking and Ripple Blanking provisions Y Low fan-in and low power Logic Diagram C1995 National Semiconductor Corporation TL F 5845 TL F 5845 - 1 RRD-B30M105 Printed in U S A Absolute Maximum Ratings (Note 1) If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications VCC Input Voltage (Except BI) 7V 6V Input Voltage (BI) Segment Output Voltage VCC 80V Power Dissipation 600 m W Maximum Power Dissipation at 25 C Cavity Package Molded Package 1509 m W 1476 m W Derate cavity package 10 06 m W C above 25 C derate molded package 11 81 m W C above 25 C Transient...