74LS47 SYC | Alldatasheet
Document overview
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Technical content
Features
■ Open-collector outputs ■ Drive indicator segments directly ■ Cascadable zero-suppression capability ■ Lamp test input Ordering Code: Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code. Logic Symbol VCC = Pin 16 GND = Pin 8 Connection Diagram Pin Descriptions Note 1: OC—Open Collector Order Number Package Number Package Description DM74LS47M M16A 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow DM74LS47N N16E 16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide Pin Names Description A0–A3 BCD Inputs RBI Ripple Blanking Input (Active LOW) LT Lamp Test Input (Active LOW) BI/RBO Blanking Input (Active LOW) or Ripple Blanking Output (Active LOW) a –g Segment Outputs (Active LOW) (Note 1) www.sycelectronica.com.ar
Note 2: 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 or a decimal 0 is not desired. X = input may be HIGH or LOW. Note 3: When a LOW level is applied to the blanking input (forced condition) all segment outputs go to a HIGH level regardless of the state of any other input condition. Note 4: When ripple-blanking input (RBI) and inputs A0, A1, A2 and A3 are 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). Note 5: 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. Functional Description The DM74LS47 decodes the input data in the pattern indi- cated in the Truth Table and the segment identification illustration. If the input data is decimal zero, a LOW signal applied to the RBI blanks the display and causes a multi- digit display. For example, by grounding the RBI of the highest order decoder and connecting its BI/RBO to RBI of the next lowest order decoder, etc., leading zeros will be suppressed. Similarly, by grounding RBI of the lowest order decoder and connecting its BI/RBO to RBI of the next high- est order decoder, etc., trailing zeros will be suppressed. Leading and trailing zeros can be suppressed simulta- neously by using external gates, i.e.: by driving RBI of a intermediate decoder from an OR gate whose inputs are BI/RBO of the next highest and lowest order decoders. BI/ RBO also serves as an unconditional blanking input. The internal NAND gate that generates the RBO signal has a resistive pull-up, as opposed to a totem pole, and thus BI/ RBO can be forced LOW by external means, using wired- collector logic. A LOW signal thus applied to BI/RBO turns off all segment outputs. This blanking feature can be used to control display intensity by varying the duty cycle of the blanking signal. A LOW signal applied to LT turns on all segment outputs, provided that BI/RBO is not forced LOW. Decimal Inputs Outputsor Note Function LT RBI A3 A2 A1 A0 BI /RBO a b c d e f g
0 HHL L L L H LLLLLLH ( N o t e 2 )
1 H X L L L H H H L L H H H H (Note 2)
2H X L L H L H L L H L L H L
3 H X L L H HHL L L L H H L
4H X L H L L H H L L H H L L
5 H X L H L HHL H L L H L L
6 HXLHHL H H HLLLLL
7 H X L H H HHL L L H H H H
8 HXHL L L H LLLLLLL
9 HXHL LH H LLLH HLL
10 H X H L H L H H H H L L H L
12 H X H H L L H H L H H H L L
1 3 H X H H L HHL H H L H L L 1 4 HXHHHL H H H HLLLL 1 5 H X H H H H H HHHHHHH BI XXXXXX L H H H H H H H ( N o t e 3 ) RBI H L L L L L L HHHHHHH ( N o t e 4 ) LT LXXXXX H LLLLLLL ( N o t e 5 ) www.sycelectronica.com.ar
Numerical Designations—Resultant Displays www.sycelectronica.com.ar
Absolute Maximum Ratings(Note 6) Note 6: 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 tables are not guaranteed at the absolute maximum ratings. The “Recommended Operating Conditions” table will define the conditions for actual device operation. Recommended Operating Conditions Note 7: OFF-State at a–g.
Electrical Characteristics
Over recommended operating free air temperature range (unless otherwise noted) Note 8: All typicals are at VCC = 5V, TA = 25°C. Note 9: Not more than one output should be shorted at a time, and the duration should not exceed one second. Switching Characteristics at VCC = +5.0V, TA = +25°C Note 10: LT = HIGH, A0–A3 = LOW Supply Voltage 7V Input Voltage 7V Operating Free Air Temperature Range 0°C to +70°C Storage Temperature Range −65°C to +150°C Symbol Parameter Min Nom Max Units V CC Supply Voltage 4.75 5 5.25 V VIH HIGH Level Input Voltage 2 V VIL LOW Level Input Voltage 0.8 V IOH HIGH Level Output Current −250 µAa − g @ 15V = VOH (Note 7) IOH HIGH Level Output Current BI /RBO −50 µA IOL LOW Level Output Current 24 mA TA Free Air Operating Temperature 0 70 °C Symbol Parameter Conditions Min Typ Max Units (Note 8) VI Input Clamp Voltage V CC = Min, II = −18 mA −1.5 V VOH HIGH Level V CC = Min, IOH = Max, 2.7 3.4 V Output Voltage V IL = Max, BI /RBO IOFF Output HIGH Current Segment Outputs VCC = 5.5V, VO = 15V a − g 250 µA VOL LOW Level V CC = Min, IOL = Max, 0.35 0.5 Output Voltage V IH = Min, a − g IOL = 3.2 mA, BI /RBO 0.5 V IOL = 12 mA, a –g 0.25 0.4 IOL = 1.6 mA, BI /RBO 0.4 II Input Current @ Max V CC = Max, VI = 7V 100 µA Input Voltage V CC = Max, VI = 10V IIH HIGH Level Input Current V CC = Max, VI = 2.7V 20 µA IIL LOW Level Input Current V CC = Max, VI = 0.4V −0.4 mA IOS Short Circuit V CC = Max (Note 9), mA Output Current I OS at BI/RBO −0.3 −2.0 ICC Supply Current V CC = Max 13 mA R L = 665Ω Symbol Parameter Conditions C L = 15 pF Units Min Max tPLH Propagation Delay 100 ns tPHL An to a –g 100 tPLH Propagation Delay 100 ns tPHL RBI to a –g (Note 10) 100 www.sycelectronica.com.ar
Physical Dimensions inches (millimeters) unless otherwise noted 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow Package Number M16A www.sycelectronica.com.ar
DM74LS47 BCD to 7-Segment Decoder/Driver with Open-Collector Outputs Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide Package Number N16E www.sycelectronica.com.ar