The MM74HC4020, MM74HC4040, are high speed binary ripple carry counters. These counters are implemented utilizing advanced silicon-gate CMOS technology to achieve speed performance similar to LS-TTL logic while retaining the low power and high noise immunity of CMOS.
The MM74HC4020 is a 14 stage counter and the MM74HC4040 is a 12-stage counter. Both devices are incremented on the falling edge (negative transition) of the input clock, and all their outputs are reset to a low level by applying a logical high on their reset input.
These devices are pin equivalent to the CD4020 and CD4040 respectively. All inputs are protected from damage due to static discharge by protection diodes to VCC and ground.
■ Typical propagation delay: 16 ns
■ Wide operating voltage range: 2–6V
■ Low input current: 1 µA maximum
■ Low quiescent current: 80 µA maximum (74HC Series)
■ Output drive capability: 10 LS-TTL loads