DM9368 7-Segment Decoder/Driver/Latch with Constant Current Source Outputs mon cathode type LED displays directly. General Description The DM9368 is a 7-segment decoder driver incorporating input latches and constant current output circuits to drive com- Connection Diagram Dual-In-Line Package DS009796-1 Order Number DM9368N See Package Number N16E Pin Name (c) 1998 Fairchild Semiconductor Corporation Description A0-A3 Address (Data) Inputs RBO Ripple Blanking Output (Active Low) RBI Ripple Blanking Input (Active Low) a-g Segment Drivers-Outputs LE Latch Enable Input (Active Low) DS009796 www.fairchildsemi.com DM9368 7-Segment Decoder/Driver/Latch with Constant Current Source Outputs March 1998 Absolute Maximum Ratings (Note 1) Supply Voltage Input Voltage Operating Free Air Temperature Range Storage Temperature Range 7V 5.5V 0C to +70C -65C to +150C Recommended Operating Conditions Symbol Parameter VCC Supply Voltage VIH High Level Input Voltage VIL Low Level Input Voltage IOH High Level Output Current DM9368 Units Min Nom Max 4.75 5 5.25 V 2 V 0.8 V -80 A IOL Low Level Output Current RBO TA Free Air Operating Temperature 0 ts(H) Setup Time High 30 ns th(H) Hold Time HIGH 0 ns 20 ns 0 ns 3.2 mA 70 C An to LE An to LE ts(L) Setup Time LOW An to LE th(L) Hold Time LOW An to LE tw(L) LE Pulse Width LOW 45 IOH Segment Output HIGH Current -16 -22 mA ns IOL Segment Output LOW Current -250 250 A Note 1: The "Absolute Maximum Ratings" are those values beyond which the safety of the device cannot be guaranteed. The device should not be operated at these limits. The parametric values defined in the "Electrical Characteristics" table are not guaranteed at the absolute maximum ratings. The "Recommended Operating Conditions" table will define the conditions for actual device operation. Electrical Characteristics Over recommended operating free air temperature range (unless otherwise noted) Symbol Parameter Conditions Min Typ Max Units -1.5 V (Note 1) VI Input Clamp Voltage VOH High Level Output Voltage VOL Low Level Output Voltage Input Current @ Max II VCC = Min, II = -12 mA VCC = Min, IOH = Max, VIL = Max 2.4 VCC = Min, IOL = Max, VIH = Min VCC = Max, VI = 5.5V 3.4 0.2 V 0.4 V 1 mA Input Voltage IIH High Level Input Current IIL Low Level Input Current IOS Short Circuit Output Current ICC Supply Current VCC = Max, VI = 2.4V VCC = Max, VI = 0.4V VCC = Max (Note 2) VCC = Max, Outputs Open, Data & Latch Inputs = 0V Note 2: All typicals are at VCC = 5V, TA = 25C. Note 3: Not more than one output should be shorted at a time. www.fairchildsemi.com 2 -18 40 A -1.6 mA -57 mA 67 mA Switching Characteristics VCC = 5.0V, TA = 25C (See Section 1 for Waveforms and Load Configuations) Symbol CL = 15 pF RL = 100 Parameter Min Units Max tPLH Propagation Delay 50 tPHL An to a-g 75 tPLH Propagation Delay 70 tPHL LE to a-g 90 ns ns Functional Description HIGH. This allows '68s to be driven from an MOS device in multiplex mode without the need for drivers on the data lines. The '68 also has provision for automatic blanking of the leading and/or trailing edge zeros in a multidigit decimal number, resulting in an easily readable decimal display conforming to normal writing practice. In an eight digit mixed integer fraction decimal representation, using the automatic blanking capability, 0060.0300 would be displayed as 60.03. Leading edge zero suppression is obtained by connecting the Ripple Blanking Output (RBO) of a decoder to the Ripple Blanking Input (RBI) of the next lower stage device. The most significant decoder stage should have the RBI input grounded; and since suppression of the least significant integer zero in a number is not usually desired, the RBI input of this decoder stage should be left open. A similar procedure for the fractional part of a display will provide automatic suppression of trailing edge zeros. The RBO terminal of the decoder can be OR-tied with a modulating signal via an isolating buffer to achieve pulse duration intensity modulation. A suitable signal can be generated for this purpose by forming a variable frequency multivibrator with a cross coupled pair of TTL or DTL gates. The '68 is a 7-segment decoder driver designed to drive 7-segment common cathode LED displays. The '68 drives any common cathode LED display rated at a nominal 20 mA at 1.7V per segment without need for current limiting resistors. This device accepts a 4-bit binary code and produces output drive to the appropriate segments of the 7-segment display. It has a hexadecimal decode format which produces numeric codes "0" thru "9" and alpha codes "A" through "F" using upper and lower case fonts. Latches on the four data inputs are controlled by an active LOW latch enable LE. When the LE is LOW, the state of the outputs is determined by the input data. When the LE goes HIGH, the last data present at the inputs is stored in the latches and the outputs remain stable. The LE pulse width necessary to accept and store data is typically 30 ns which allows data to be strobed into the '68 at normal TTL speeds. This feature means that data can be routed directly from high speed counters and frequency dividers into the display without slowing down the system clock or providing intermediate data storage. Another feature of the '68 is that the unit loading on the data inputs is very low (-100 A Max) when the latch enable is Logic Symbol DS009796-2 VCC = Pin 16 GND = PIN 8 3 www.fairchildsemi.com Truth Table DS009796-4 DS009796-8 *The RBI will blank the display only if a binary zero is stored in the latches. *The RBO used as an input overrides all other input conditions. H = HIGH Voltage Level L = LOW Voltage Level X = Immaterial Logic Diagram DS009796-3 www.fairchildsemi.com 4 Numerical Designations DS009796-5 Parallel Data Display System with Ripply Blanking Common Cathode LED Display DS009796-6 5 www.fairchildsemi.com Display Demultiplexing System with Ripple Blanking Common Cathode LED Display DS009796-7 Note: Digit address data must be non-overlapping. Standard TTL decoders like the 9301, 9311, 7442 or 74155 must be strobed, since the address decoding glitches could cause erroneous data to be strobed into the latches. www.fairchildsemi.com 6 7 DM9368 7-Segment Decoder/Driver/Latch with Constant Current Source Outputs Physical Dimensions inches (millimeters) unless otherwise noted 16-Lead Molded Dual-In-Line Package (N) Order Number DM9368N Package Number N16E LIFE SUPPORT POLICY FAIRCHILD'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 FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 2. A critical component in any component of a life support 1. Life support devices or systems are devices or sysdevice or system whose failure to perform can be reatems which, (a) are intended for surgical implant into sonably expected to cause the failure of the life support the body, or (b) support or sustain life, and (c) whose device or system, or to affect its safety or effectiveness. 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. Fairchild Semiconductor Corporation Americas Customer Response Center Tel: 1-888-522-5372 www.fairchildsemi.com Fairchild Semiconductor Europe Fax: +49 (0) 1 80-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 8 141-35-0 English Tel: +44 (0) 1 793-85-68-56 Italy Tel: +39 (0) 2 57 5631 Fairchild Semiconductor Hong Kong Ltd. 13th Floor, Straight Block, Ocean Centre, 5 Canton Rd. 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