General Description
The MM74C925 and MM74C926 CMOS counters consist of a 4-digit counter, an internal output latch, NPN output sourcing drivers for a 7-segment display, and an internal multiplexing circuitry with four multiplexing outputs. The multiplexing circuit has its own free-running oscillator, and requires no external clock. The counters advance on negative edge of clock. A HIGH signal on the Reset input will reset the counter to zero, and reset the carry-out LOW. A LOW signal on the Latch Enable input will latch the number in the counters into the internal output latches. A HIGH signal on Display Select input will select the number in the counter to be displayed; a LOW level signal on the Display Select will select the number in the output latch to be displayed.
The MM74C925 is a 4-decade counter and has Latch Enable, Clock and Reset inputs.
The MM74C926 is like the MM74C925 except that it has a display select and a carry-out used for cascading counters. The carry-out signal goes HIGH at 6000, goes back LOW at 0000.
Features
■ Wide supply voltage range: 3V to 6V
■ Guaranteed noise margin: 1V
■ High noise immunity: 0.45 VCC (typ.)
■ High segment sourcing current: 40 mA @ VCC − 1.6V, VCC = 5V
■ Internal multiplexing circuitry
Feature
General Description
The MM74C925 and MM74C926 CMOS counters consist of a 4-digit counter, an internal output latch, NPN output sourcing drivers for a 7-segment display, and an internal multiplexing circuitry with four multiplexing outputs. The multiplexing circuit has its own free-running oscillator, and requires no external clock. The counters advance on negative edge of clock. A HIGH signal on the Reset input will reset the counter to zero, and reset the carry-out LOW. A LOW signal on the Latch Enable input will latch the number in the counters into the internal output latches. A HIGH signal on Display Select input will select the number in the counter to be displayed; a LOW level signal on the Display Select will select the number in the output latch to be displayed.
The MM74C925 is a 4-decade counter and has Latch Enable, Clock and Reset inputs.
The MM74C926 is like the MM74C925 except that it has a display select and a carry-out used for cascading counters. The carry-out signal goes HIGH at 6000, goes back LOW at 0000.
Features
■ Wide supply voltage range: 3V to 6V
■ Guaranteed noise margin: 1V
■ High noise immunity: 0.45 VCC (typ.)
■ High segment sourcing current: 40 mA @ VCC − 1.6V, VCC = 5V
■ Internal multiplexing circuitry
