74LS47 Introduction: BCD to 7 segment decoder IC [Video]

74LS47 is a BCD to 7-segment decoder/driver IC.

This is an introduction blog to 74LS47 BCD to 7-segment decoder ic, which will cover as much information as possible, including its pinout, features, some useful application circuits and other information. Anyway, i hope you guys like it!

This tutorial video shows how to use 74LS47 in a display project.

Catalog

74LS47 Description

74LS47 is a Low Power Schottky BCD to 7-Segment Decoder/Driver consisting of NAND gates, input buffers and 7 AND-OR-INVERT gates. They offer direct active low, high sink current outputs for driving indicators. Seven NAND gates and one driver are connected in pairs to make BCD data and its complement available to the seven AND-OR-INVERT gates.

74LS47 Pinout

74LS47	74LS47 Pinout

74LS47 Features

• Function: Decoder, Demultiplexer

• Technology Family: LS

• VCC (Min): 4.75V

• VCC (Max): 5.25V

• Channels: 1

• Voltage (Nom): 5V

• Max Frequency at normal Voltage: 35Mhz

• tpd at normal Voltage (Max): 100 nsec

• Configuration: 4:7

• Type: Open-Collector

• IOL (Max): 3.2mA

• IOH (Max): -0.05mA

• Rating: Catalog

• Operating temperature range (C): 0 to 70

• Bits (#): 7

• Digital input leakage (Max): 5uA

• ESD CDM (kV): 0.75

• ESD HBM (kV): 2

74LS47 Parameter

74LS47 Application Circuits

74LS47 has integral ripple-blanking facilities, but does not include data latches.

Figure 1 shows the functional diagrams and pin designations of these devices, each of which is housed in a 16-pin package.

Figure 1. Functional diagram of the 74LS47 BCD-to-seven-segment decoder/driver ICs.

The 74LS47 has active-low outputs designed to drive a common-anode LED display via external current-limiting resistors (Rx) as shown in Figure 2.

Figure 2. Basic way of using a 74LS47 IC to drive a common-anode LED display.

Note: Figure 1 shows that each of these ICs has three input 'control' terminals, which are designated LT (Lamp Test), BI/RBO, and RBI. The LT terminal drives all display outputs when the terminal is connected to logic 0 with the RBO terminal open or to logic 1.

When the BI/RBO terminal is pulled low, all outputs are cleared; this pin also functions as a ripple-blanking output terminal. Figure 3 shows how to connect the ripple-blanking terminals to the leading zero suppression on the first three digits of the four-digit display.

Figure 3. Method of applying leading-zero suppression to the first three digits of a four-digit display using 74LS47 ICs.

74LS47 Package

74LS47 Manufacturer

Texas Instruments Inc. (TI) is an American technology company that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globally. Its headquarters are in Dallas, Texas, United States. TI is one of the top ten semiconductor companies worldwide, based on sales volume. Texas Instruments's focus is on developing analog chips and embedded processors, which accounts for more than 80% of their revenue. TI also produces TI digital light processing (DLP) technology and education technology products including calculators, microcontrollers and multi-core processors. To date, TI has more than 43,000 patents worldwide.

Component Datasheet

74LS47 Datasheet

FAQ