SN54/74LS47 BCD TO 7-SEGMENT DECODER/DRIVER The SN54 / 74LS47 are Low Power Schottky BCD to 7-Segment Decoder / Drivers consisting of NAND gates, input buffers and seven AND-OR-INVERT gates. They offer active LOW, high sink current outputs for driving indicators directly. Seven NAND gates and one driver are connected in pairs to make BCD data and its complement available to the seven decoding AND-OR-INVERT gates. The remaining NAND gate and three input buffers provide lamp test, blanking input / ripple-blanking output and ripple-blanking input. The circuits accept 4-bit binary-coded-decimal (BCD) and, depending on the state of the auxiliary inputs, decodes this data to drive a 7-segment display indicator. The relative positive-logic output levels, as well as conditions required at the auxiliary inputs, are shown in the truth tables. Output configurations of the SN54 / 74LS47 are designed to withstand the relatively high voltages required for 7-segment indicators. These outputs will withstand 15 V with a maximum reverse current of 250 µA. Indicator segments requiring up to 24 mA of current may be driven directly from the SN74LS47 high performance output transistors. Display patterns for BCD input counts above nine are unique symbols to authenticate input conditions. The SN54 / 74LS47 incorporates automatic leading and / or trailing-edge zero-blanking control (RBI and RBO). Lamp test (LT) may be performed at any time which the BI / RBO node is a HIGH level. This device also contains an overriding blanking input (BI) which can be used to control the lamp intensity by varying the frequency and duty cycle of the BI input signal or to inhibit the outputs. • • • • • BCD TO 7-SEGMENT DECODER/ DRIVER LOW POWER SCHOTTKY J SUFFIX CERAMIC CASE 620-09 16 1 N SUFFIX PLASTIC CASE 648-08 16 Lamp Intensity Modulation Capability (BI/RBO) Open Collector Outputs Lamp Test Provision Leading / Trailing Zero Suppression Input Clamp Diodes Limit High-Speed Termination Effects 1 D SUFFIX SOIC CASE 751B-03 16 1 ORDERING INFORMATION CONNECTION DIAGRAM DIP (TOP VIEW) VCC 16 f g a b c d e 15 14 13 12 11 10 9 SN54LSXXJ SN74LSXXN SN74LSXXD Ceramic Plastic SOIC LOGIC SYMBOL 7 1 2 6 3 5 1 2 3 4 B C LT BI / RBO RBI PIN NAMES 5 6 7 8 D A GND LOADING (Note a) HIGH A, B, C, D RBI LT BI / RBO a, to g A B C D LT RBI BCD Inputs Ripple-Blanking Input Lamp-Test Input Blanking Input or Ripple-Blanking Output Outputs 0.5 U.L. 0.5 U.L. 0.5 U.L. 0.5 U.L. 1.2 U.L. Open-Collector LOW 0.25 U.L. 0.25 U.L. 0.25 U.L. 0.75 U.L. 2.0 U.L. 15 (7.5) U.L. NOTES: a) 1 Unit Load (U.L.) = 40 µA HIGH, 1.6 mA LOW. b) Output current measured at VOUT = 0.5 V The Output LOW drive factor is 7.5 U.L. for Military (54) and 15 U.L. for Commercial (74) Temperature Ranges. FAST AND LS TTL DATA 5-56 a b c d e BI/ f g RBO 13 12 11 10 9 15 14 4 VCC = PIN 16 GND = PIN 8 SN54/74LS47 LOGIC DIAGRAM a a b b c c d d e e f f g g A B INPUT C D OUTPUT BLANKING INPUT OR RIPPLE-BLANKING OUTPUT LAMP-TEST INPUT RIPPLE-BLANKING INPUT 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 NUMERICAL DESIGNATIONS — RESULTANT DISPLAYS TRUTH TABLE INPUTS OUTPUTS DECIMAL OR FUNCTION LT RBI D C B 0 H H L L 1 H X L L 2 H X L 3 H X 4 H X 5 H 6 A BI/RBO a b c L L L H L H L L L H X L H X 7 H 8 9 d H L L L L H H L L H L H L L H L H H H L L L L L H H L L H L H H L H L L H H L H H H X L H H H H L H X H L L L H H X H L L H H 10 H X H L H L 11 H X H L H 12 H X H H 13 H X H 14 H X 15 H e f g NOTE L L H A H H H A L H L L H H L H H L L L H L L L L L L L L L H H H H L L L L L L L L L L H H L L H H H H L L H L H H H H L L H H L L L H H L H H H L L H L H H L H H L H L L H H H L H H H H L L L L X H H H H H H H H H H H H BI X X X X X X L H H H H H H H B RBI H L L L L L L H H H H H H H C LT L X X X X X H L L L L L L L D H = HIGH Voltage Level L = LOW Voltage Level X = Immaterial NOTES: (A) BI/RBO is wire-AND logic serving as blanking Input (BI) and/or ripple-blanking output (RBO). The blanking out (BI) must be open or held at a HIGH level when output functions 0 through 15 are desired, and ripple-blanking input (RBI) must be open or at a HIGH level if blanking of a decimal 0 is not desired. X = input may be HIGH or LOW. (B) When a LOW level is applied to the blanking input (forced condition) all segment outputs go to a LOW level regardless of the state of any other input condition. (C) When ripple-blanking input (RBI) and inputs A, B, C, and D are at LOW level, with the lamp test input at HIGH level, all segment outputs go to a HIGH level and the ripple-blanking output (RBO) goes to a LOW level (response condition). (D) When the blanking input/ripple-blanking output (BI/RBO) is open or held at a HIGH level, and a LOW level is applied to lamp test input, all segment outputs go to a LOW level. FAST AND LS TTL DATA 5-57 SN54/74LS47 GUARANTEED OPERATING RANGES Min Typ Max Unit VCC Symbol Supply Voltage Parameter 54 74 4.5 4.75 5.0 5.0 5.5 5.25 V TA Operating Ambient Temperature Range 54 74 – 55 0 25 25 125 70 °C IOH Output Current — High BI / RBO 54, 74 – 50 µA IOL Output Current — Low BI / RBO BI / RBO 54 74 1.6 3.2 mA VO (off) IO (on) Off-State Output Voltage a to g 54, 74 15 V On-State Output Current a to g On-State Output Current a to g 54 74 12 24 mA DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified) Limits Symbol Parameter Min VIH Input HIGH Voltage VIL Input LOW Voltage VIK Input Clamp Diode Voltage VOH Output HIGH Voltage, BI / RBO VOL Output LOW Voltage BI / RBO IO (off) Off-State Output Current a thru g VO (on) On-State Output Voltage a thru g IIH Input HIGH Current IIL Input LOW Current BI/ RBO Any Input except BI / RBO IOS BI / RBO ICC Typ Unit Max 2.0 54 0.7 74 0.8 – 0.65 2.4 – 1.5 V V Guaranteed Input LOW Threshold Voltage for All Inputs V 4.2 Test Conditions Guaranteed Input HIGH Theshold Voltage for All Inputs V VCC = MIN, IIN = – 18 mA VCC = MIN, IOH = – 50 µA, VIN = VIN or VIL per Truth Table 54, 74 0.25 0.4 V 74 0.35 0.5 V 250 µA VCC = MAX, VIN = VIN or VIL per Truth Table, VO (off) = 15 V IO (on) = 12 mA IO (on) = 24 mA 54, 74 0.25 0.4 V 74 0.35 0.5 V Output Short Circuit Current (Note 1) – 0.3 Power Supply Current 7.0 IOL = 1.6 mA IOL = 3.2 mA VCC = MIN, VIN = VIN or VIL per Truth Table VCC = MAX, VIN = VIH or VIL per Truth Table 20 µA 0.1 mA VCC = MAX, VIN = 2.7 V VCC = MAX, VIN = 7.0 V – 1.2 – 0.4 mA VCC = MAX, VIN = 0.4 V –2.0 mA 13 mA VCC = MAX, VOUT = 0 V VCC = MAX Note 1: Not more than one output should be shorted at a time, nor for more than 1 second. AC CHARACTERISTICS (TA = 25°C) Limits Symbol Parameter Min Typ Max Unit tPHL tPLH Propagation Delay, Address Input to Segment Output 100 100 ns ns tPHL tPLH Propagation Delay, RBI Input To Segment Output 100 100 ns ns Test Conditions VCC = 5.0 V CL = 15 pF AC WAVEFORMS VIN VOUT 1.3 V 1.3 V tPHL tPLH 1.3 V VIN 1.3 V 1.3 V tPLH tPHL VOUT 1.3 V Figure 1 1.3 V 1.3 V Figure 2 FAST AND LS TTL DATA 5-58