1 Features

• Fully static operation

• Buffered inputs

• Common reset

• Negative-edge clocking

• Fanout (over temperature range):

– Standard outputs 10 LSTTL loads

– Bus driver outputs 15 LSTTL loads

• Wide operating temperature range: –55℃ to 125℃

• Balanced propagation delay and transition times

• Significant power reduction compared to LSTTL

Logic ICs

• HC types

– 2 V to 6 V operation

– High noise immunity: NIL = 30%, NIH = 30% of

VCC at VCC = 5 V

• HCT types

– 4.5 V to 5.5 V operation

– Direct LSTTL input logic compatibility,

VIL = 0.8 V (max), VIH = 2 V (min)

– CMOS input compatibility, II ≤ 1 μA at VOL, VOH

2 Description

The ’HC393 and ’HCT393 are 4-stage ripple-carry

binary counters. All counter stages are primaryoperative

flip-flops. The state of the stage advances

one count on the negative transition of each clock

pulse; a high voltage level on the MR line resets all

counters to their zero state. All inputs and outputs are

buffered.