DS8884A High Voltage Cathode Decoder/Driver General Description Features The DS8884A is designed to decode four lines of BCD input and drive seven-segment digits of gas-filled readout displays. All outputs consist of switchable and programmable current sinks which provide constant current to the tube cathodes, even with high tube anode supply tolerance. Output currents may be varied over the 0.2 mA to 1.2 mA range for multiplex operation. The output current is adjusted by connecting an external program resistor (RP) from VCC to the program input in accordance with the programming curve. Unused outputs must be tied to VCC. Y Y Y Y Y Y Y Usable with AC or DC input coupling Current sink outputs High output breakdown voltage Low input load current Intended for multiplex operation Input pullups increase noise immunity Comma/d.pt. drive Connection Diagram Dual-In-Line Package TL/F/5847 – 2 Top View Order Number DS8884AN See NS Package Number N18A C1995 National Semiconductor Corporation TL/F/5847 RRD-B30M105/Printed in U. S. A. DS8884A High Voltage Cathode Decoder/Driver May 1986 Absolute Maximum Ratings (Note 1) Storage Temperature Range b 65§ C to a 150§ C If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/Distributors for availability and specifications. Maximum Power Dissipation* at 25§ C Molded Package VCC *Derate molded package 13.71 mW/§ C above 25§ C. Input Voltage (Note 4) Segment Output Voltage Power Dissipation Transient Segment Output Current (Note 5) 7V VCC 80V 600 mW 1714 mW Operating Conditions Supply Voltage (VCC) Temperature (TA) 50 mA Min 4.75 0 Max 5.25 a 70 Units V §C Electrical Characteristics (Notes 2 and 3) Symbol VIH Parameter Conditions Min Max 2.0 Units Logical ‘‘1’’ Input Voltage VCC e 4.75V VIL Logical ‘‘0’’ Input Voltage VCC e 4.75V 1.0 V IIH Logical ‘‘1’’ Input Current VCC e 5.25V, VIN e 2.4V 15 mA IIL Logical ‘‘0’’ Input Current VCC e 5.25V, VIN e 0.4V b 250 mA ICC Power Supply Current VCC e 5.25V, RP e 2.8k, All Inputs e 5V 40 mA VI a Positive Input Clamp Voltage VCC e 4.75V, IIN e 1 mA VIb Negative Input Clamp Voltage VCC e 5V, IIN e b12 mA, TA e 25§ C b 1.5 V DIO SEGMENT OUTPUTS ‘‘ON’’ Current Ratio All Outputs e 50V, IOUT b e Ref., All Outputs Ib ON Output b ‘‘ON’’ Current VCC e 5V, VOUT b e 50V, TA e 25§ C ICEX Output Leakage Current VOUT e 75V VBR Output Breakdown Voltage IOUT e 250 mA tpd Propagation Delay of Any Input to Segment Output VCC e 5V,TA e 25§ C V 5.0 V 0.9 1.1 RP e 18.1k 0.15 0.25 mA RP e 7.03k 0.45 0.55 mA RP e 3.40k 0.90 1.10 mA RP e 2.80k 1.08 1.32 mA 5 mA 80 V 10 ms Note 1: ‘‘Absolute Maximum Ratings’’ are those values beyond which the safety of the device cannot be guaranteed. They are not meant to imply that the devices should be operated at these limits. The table of ‘‘Electrical Characteristics’’ provides conditions for actual device operation. Note 2: Unless otherwise specified min/max limits apply across the 0§ C to a 70§ C temperature range for the DS8884A. All typical values are for TA e 25§ C and VCC e 5V. Note 3: All currents into device pins shown as positive, out of device pins as negative, all voltages referenced to ground unless otherwise noted. All values shown as max or min on absolute value basis. Note 4: This limit can be higher for a current limiting voltage source. Note 5: In all applications transient segment output current must be limited to 50 mA. This may be accomplished in DC applications by connecting a 2.2k resistor from the anode-supply filter capacitor to the display anode, or by current limiting the anode driver in multiplex applications. Typical Application TL/F/5847 – 4 2 Truth Table TL/F/5847 – 3 *Decimal point and comma can be displayed with or without any numeral. Logic Diagram TL/F/5847 – 1 3 DS8884A High Voltage Cathode Decoder/Driver Physical Dimensions inches (millimeters) Molded Dual-In-Line Package (N) Order Number DS8884AN NS Package Number N18A LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 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