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

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.įigure 3. When the BI/RBO terminal is pulled low, all outputs are cleared this pin also functions as a ripple-blanking output terminal. The LT terminal drives all display outputs when the terminal is connected to logic 0 with the RBO terminal open or to logic 1. Note: Figure 1 shows that each of these ICs has three input 'control' terminals, which are designated LT (Lamp Test), BI/RBO, and RBI. Basic way of using a 74LS47 IC to drive a common-anode LED display. 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.įigure 2.

Functional diagram of the 74LS47 BCD-to-seven-segment decoder/driver ICs. 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.ħ4LS47 has integral ripple-blanking facilities, but does not include data latches.įigure 1 shows the functional diagrams and pin designations of these devices, each of which is housed in a 16-pin package.įigure 1.

They offer direct active low, high sink current outputs for driving indicators. This tutorial video shows how to use 74LS47 in a display project.ħ4LS47 is a Low Power Schottky BCD to 7-Segment Decoder/Driver consisting of NAND gates, input buffers and 7 AND-OR-INVERT gates.

Multisim 7 segment display imput