SN54/74LS48 BCD TO 7-SEGMENT DECODER

1 SN54/74LS48 . BCD TO 7-SEGMENT . DECODER . The SN54 / 74LS48 is a BCD to 7-SEGMENT DECODER consisting of NAND. gates, input buffers and seven AND-OR-INVERT gates. Seven NAND gates and one driver are connected in pairs to make BCD data and its complement BCD TO 7-SEGMENT . available to the seven decoding AND-OR-INVERT gates. The remaining DECODER . NAND gate and three input buffers provide lamp test, blanking input/ripple- blanking input for the LS48. LOW POWER SCHOTTKY. The circuit accepts 4-bit binary-coded-decimal (BCD) and, depending on the state of the auxiliary inputs, decodes this data to drive other components. The relative positive logic output levels, as well as conditions required at the auxiliary inputs, are shown in the truth tables. The LS48 circuit incorporates automatic leading and / or trailing edge J SUFFIX. zero-blanking control (RBI and RBO). Lamp Test (LT) may be activated any CERAMIC. time when the BI / RBO node is HIGH.

2 Both devices contain an overriding CASE 620-09. blanking input (BI) which can be used to control the lamp intensity by varying 16. the frequency and duty cycle of the BI input signal or to inhibit the outputs. 1. Lamp Intensity Modulation Capability (BI/RBO). Internal Pull-Ups Eliminate Need for External Resistors Input Clamp Diodes Eliminate High-Speed Termination Effects N SUFFIX. PLASTIC. CASE 648-08. CONNECTION DIAGRAM DIP (TOP VIEW) 16. VCC f g a b c d e 1. 16 15 14 13 12 11 10 9. D SUFFIX. SOIC. 16. 1 CASE 751B-03. 1 2 3 4 5 6 7 8 ORDERING INFORMATION. B C LT BI / RBO RBI D A GND SN54 LSXXJ Ceramic SN74 LSXXN Plastic LOGIC DIAGRAM SN74 LSXXD SOIC. a A LOGIC SYMBOL. b 7 1 2 6 3 5. B. INPUT. A B C D LT RBI. C c D SN54 / 74LS48. OUTPUT BI/. d a b c d e f g RBO. BLANKING INPUT OR. RIPPLE-BLANKING. OUTPUT e 13 12 11 10 9 15 14 4. VCC = PIN 16. GND = PIN 8. f RIPPLE-BLANKING. INPUT. LAMP-TEST. INPUT g FAST AND LS TTL DATA.

3 5-59. SN54/74LS48 . PIN NAMES LOADING (Note a). HIGH LOW. A, B, C, D BCD Inputs RBI Ripple-Blanking (Active Low) Input LT Lamp-Test (Active Low) Input BI / RBO Blanking Input or Ripple- Blanking Output (Active Low) 2(1) BI Blanking (Active Low) Input Open-Collector ( ) (48). NOTES: a) Unit Load ( ) = 40 A HIGH / mA LOW. b) Outut current measured at VOUT = V. Output LOW drive factor is SN54LS / 74LS48: for Military (54), for Commercial (74). 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15. NUMERICAL DESIGNATIONS RESULTANT DISPLAYS. TRUTH TABLE. SN54 / 74LS48. INPUTS OUTPUTS. DECIMAL. OR LT RBI D C B A BI / RBO a b c d e f g NOTE. FUNCTION. 0 H H L L L L H H H H H H H L 1. 1 H X L L L H H L H H L L L L 1. 2 H X L L H L H H H L H H L H NOTES: 3 H X L L H H H H H H H L L H (1) BI/RBO is wired-AND logic serving as blanking input (BI) and/or 4 H X L H L L H L H H L L H H ripple-blanking output (RBO). The blanking out (BI) must be open or held at a HIGH level when output functions 0 through 15 are 5 H X L H L H H H L H H L H H.

4 Desired, and ripple-blanking input (RBI) must be open or at a HIGH. 6 H X L H H L H L L H H H H H. level if blanking of a decimal 0 is not desired. X=input may be HIGH. 7 H X L H H H H H H H L L L L or LOW. 8 H X H L L L H H H H H H H H (2) When a LOW level is applied to the blanking input (forced condition). 9 H X H L L H H H H H L L H H. all segment outputs go to a LOW level, regardless of the state of any other input condition. 10 H X H L H L H L L L H H L H. (3) When ripple-blanking input (RBI) and inputs A, B, C, and D are at 11 H X H L H H H L L H H L L H LOW level, with the lamp test input at HIGH level, all segment 12 H X H H L L H L H L L L H H outputs go to a HIGH level and the ripple-blanking output (RBO). 13 H X H H L H H H L L H L H H goes to a LOW level (response condition). (4) When the blanking input/ripple-blanking output (BI/RBO) is open or 14 H X H H H L H L L L H H H H. held at a HIGH level, and a LOW level is applied to lamp-test input, 15 H X H H H H H L L L L L L L all segment outputs go to a LOW level.

5 BI X X X X X X L L L L L L L L 2. RBI H L L L L L L L L L L L L L 3. LT L X X X X X H H H H H H H H 4. FAST AND LS TTL DATA. 5-60. SN54/74LS48 . GUARANTEED OPERATING RANGES. Symbol Parameter Min Typ Max Unit VCC Supply Voltage 54 V. 74 TA Operating Ambient Temperature Range 54 55 25 125 C. 74 0 25 70. IOH Output Current High a to g 54, 74 100 A. IOH Output Current High BI / RBO 54, 74 50 A. IOL Output Current Low a to g 54 mA. 74 IOL Output Current Low BI / RBO 54 mA. BI / RBO 74 DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified). Limits Symbol Parameter Min Typ Max Unit Test Conditions Guaranteed Input HIGH Voltage for VIH Input HIGH Voltage V. All Inputs 54 Guaranteed Input LOW Voltage for VIL Input LOW Voltage V. 74 All Inputs VIK Input Clamp Diode Voltage V VCC = MIN, IIN = 18 mA. VCC = MIN, IOH = 50 A, VOH Output HIGH Voltage A. VIN = VIH or per Truth Table VCC = MIN, VO = V.

6 IO Output Current a to g mA. Input Conditioner as for VOH. 54, 74 V IOL = mA VCC = MIN, VIH = V. VOL Output LOW Voltage a to g 74 V IOL = mA VIL = VIL MAX. Output LOW Voltage 54, 74 V IOL = mA VCC = MAX, VIH = V. VOL. BI / RBO 74 V IOL = mA VIL = VIL MAX. Input HIGH Current 20 A VCC = MAX, VIN = V. IIH. (Except BI / RBO) mA VCC = MAX, VIN = V. Input LOW Current IIL mA VCC = MAX, VIN = V. (Except BI / RBO). IIL Input LOW Current BI/ RBO mA VCC = MAX, VIN = V. ICC Power Supply Current 25 38 mA VCC = MAX. IOS Short Circuit Current BI/ RBO (Note 1) mA VCC = MAX. Note 1: Not more than one output should be shorted at a time, nor for more than 1 second. AC CHARACTERISTICS (VCC = V, TA = 25 C). Limits Symbol Parameter Min Typ Max Unit Test Conditions Propagation Delay Time, HIGH-to-LOW. tPHL 100 ns Level Output from A Input CL = 15 pF, RL = k . Propagation Delay Time, LOW-to-HIGH. tPLH 100 ns Level Output from A Input Propagation Delay Time, HIGH-to-LOW.

7 TPHL 100 ns Level Output from RBI Input CL = 15 pF, RL = k . Propagation Delay Time, LOW-to-HIGH. tPLH 100 ns Level Output from RBI Input FAST AND LS TTL DATA. 5-61. This datasheet has been download from: Datasheets for electronics components.