NXP 数字逻辑IC 计数器 74HC393D

74HC393D

74HC393D

74HC393D

FEATURES

• Two 4-bit binary counters with individual clocks

• Divide-by any binary module up to 28 in one package

• Two master resets to clear each 4-bit counter

individually

• Output capability: standard

• ICC category: MSI

GENERAL DESCRIPTION

The 74HC/HCT393 are high-speed Si-gate CMOS devices

and are pin compatible with low power Schottky TTL

(LSTTL). They are specified in compliance with JEDEC

standard no. 7A.

The 74HC/HCT393 are 4-bit binary ripple counters with

separate clocks (1CP and 2 CP) and master reset (1MR

and 2MR) inputs to each counter. The operation of each

half of the “393” is the same as the “93” except no external

clock connections are required.

The counters are triggered by a HIGH-to-LOW transition of

the clock inputs. The counter outputs are internally

connected to provide clock inputs to succeeding stages.

The outputs of the ripple counter do not change

synchronously and should not be used for high-speed

address decoding.

The master resets are active-HIGH asynchronous inputs

to each 4-bit counter identified by the “1” and “2” in the pin

description.

A HIGH level on the nMR input overrides the clock and

sets the outputs LOW.