CD74HC161, CD74HCT161,
CD74HC163, CD74HCT163
Data sheet acquired from Harris Semiconductor
SCHS154
High Speed CMOS Logic
Presettable Counters
February 1998
Features
Description
• CD74HC161, CD74HCT161 4-Bit Binary Counter,
Asynchronous Reset
The Harris CD74HC161, CD74HCT161, CD74HC163 and
CD74HCT163 are presettable synchronous counters that
feature look-ahead carry logic for use in high-speed
counting applications. The CD74HC161 and CD74HCT161
are asynchronous reset decade and binary counters,
respectively; the CD74HC163 and CD74HCT163 devices
decade and binary counters, respectively and are reset
synchronously with the clock. Counting and parallel
presetting are both accomplished synchronously with the
negative-to-positive transition of the clock.
[ /Title
(CD74
HC161
,
CD74
HCT16
1,
CD74
HC163
,
CD74
HCT16
3)
• CD74HC163, CD74HCT163 4-Bit Binary Counter,
Synchronous Reset
• Synchronous Counting and Loading
• Two Count Enable Inputs for n-Bit Cascading
• Look-Ahead Carry for High-Speed Counting
• Fanout (Over Temperature Range)
- Standard Outputs. . . . . . . . . . . . . . . 10 LSTTL Loads
A low level on the synchronous parallel enable input, SPE,
disables counting operation and allows data at the P0 to P3
- Bus Driver Outputs . . . . . . . . . . . . . 15 LSTTL Loads
o
o
• Wide Operating Temperature Range . . . -55 C to 125 C inputs to be loaded into the counter (provided that the
setup and hold requirements for SPE are met).
• Balanced Propagation Delay and Transition Times
All counters are reset with a low level on the Master Reset
input, MR. In the CD74HC163 and CD74HCT163 counters
(synchronous reset types), the requirements for setup and
hold time with respect to the clock must be met.
• Significant Power Reduction Compared to LSTTL
Logic ICs
• HC Types
/Sub-
ject
- 2V to 6V Operation
Two count enables, PE and TE, in each counter are
provided for n-bit cascading. In all counters reset action
occurs regardless of the level of the SPE, PE and TE inputs
(and the clock input, CP, in the CD74HC161 and
CD74HCT161 types).
- High Noise Immunity: N = 30%, N = 30% of V
IL IH CC
(High
Speed
CMOS
Logic
Preset-
table
at V
= 5V
CC
• HCT Types
- 4.5V to 5.5V Operation
- Direct LSTTL Input Logic Compatibility,
V = 0.8V (Max), V = 2V (Min)
If a decade counter is preset to an illegal state or assumes
an illegal state when power is applied, it will return to the
normal sequence in one count as shown in state diagram.
IL
IH
- CMOS Input Compatibility, I ≤ 1µA at V , V
OL OH
l
Counte
rs)
/Autho
r ()
/Key-
words
(High
Speed
CMOS
Logic
Preset-
table
The look-ahead carry feature simplifies serial cascading of
the counters. Both count enable inputs (PE and TE) must
be high to count. The TE input is gated with the Q outputs
of all four stages so that at the maximum count the terminal
count (TC) output goes high for one clock period. This TC
pulse is used to enable the next cascaded stage.
Ordering Information
PKG.
NO.
o
PART NUMBER TEMP. RANGE ( C) PACKAGE
CD74HC161E
CD74HC161M
CD74HC163E
CD74HC163M
CD74HCT161E
CD74HCT161M
CD74HCT163E
CD74HCT163M
NOTES:
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
16 Ld PDIP
E16.3
16 Ld SOIC M16.15
16 Ld PDIP E16.3
16 Ld SOIC M16.15
16 Ld PDIP E16.3
16 Ld SOIC M16.15
16 Ld PDIP E16.3
16 Ld SOIC M16.15
Pinout
CD74HC161, CD74HCT161, CD74HC163, CD74HCT163
(PDIP, SOIC)
TOP VIEW
MR
CP
P0
1
2
3
4
5
6
7
8
16 V
CC
15 TC
14 Q0
13 Q1
12 Q2
11 Q3
10 TE
Counte
rs,
High
Speed
P1
P2
1. When ordering, use the entire part number. Add the suffix 96 to ob-
tain the variant in the tape and reel.
P3
PE
2. Wafer and die for this part number is available which meets all elec-
trical specifications. Please contact your local sales office or Harris
customer service for ordering information.
9
SPE
GND
CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.
File Number 1550.1
Copyright © Harris Corporation 1998
1