1 Features

• Buffered inputs and outputs

• Typical propagation delay: 13ns at VCC = 5V, CL =

15pF, TA = 25oC

• Fanout (over temperature range)

– Bus driver outputs: 15 LSTTL loads

• Wide operating temperature range: -55oC to 125oC

• Balanced propagation delay and transition times

• Significant power reduction compared to LSTTL

logic ICs

• HC types

– 2V to 6V Operation

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

VCC at VCC = 5V

• HCT types

– 4.5V to 5.5V Operation

– Direct LSTTL input logic compatibility, VIL= 0.8V

(Max), VIH = 2V (Min)

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

2 Description

The CDx4HC147 and CD74HCT147 are 9-input

priority encoders. These devices provide the 10-line to

4-line priority encoding function by use of the implied

decimal “zero.”