
TOSHIBA
TOSHIBA CORPORATION
1/3
TC74AC Series
TC74AC393
The information contained here is subject to change without notice.
The information contained herein is presented only as guide for the applications of our products. No responsibility is assumed by TOSHIBA for any infringements of patents or other rights of the third parties
which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of TOSHIBA or others. These TOSHIBA products are intended for usage in general electronic
equipments (office equipment, communication equipment, measuring equipment, domestic electrification, etc.) Please make sure that you consult with us before you use these TOSHIBA products in equip-
ments which require high quality and/or reliability, and in equipments which could have major impact to the welfare of human life (atomic energy control, spaceship, traffic signal, combustion control, all types
of safety devices, etc.). TOSHIBA cannot accept liability to any damage which may occur in case these TOSHIBA products were used in the mentioned equipments without prior consultation with TOSHIBA.
Features:
High Speed:
f
MAX
= 180MHz (typ.) at V
CC
= 5V
Low Power Dissipation:
I
CC
= 8
μ
A (max.) at T
a
= 25
°
C
High Noise Immunity:
V
NIH
= V
NIL
= 28% V
CC
(min.)
Symmetrical Output Impedance:
S
I
OH
S
= I
OL
= 24mA
(min.). Capability of driving 50
transmission lines.
Balanced Propagation Delays:
t
pLH
= t
pHL
Wide Operating Voltage Range:
V
CC
(opr.) = 2V~5.5V
Pin and Function Compatible with 74HC393
Available in 14-pin DIP and 150 mil SOIC
Pin Assignment
The TC74AC393 is an advanced high speed CMOS DUAL
BINARY COUNTER fabricated with silicon gate and double-
layer metal wiring C
2
MOS technology.
It achieves the high speed operation similar to equivalent
Bipolar Schottky TTL, while maintaining the CMOS low
power dissipation.
It contains two independent counter circuits in one pack-
age, so that counting or frequency division of eight binary bits
can be achieved with one IC.
This device changes state on the negative going transition
of the CLOCK pulse. The counter can be reset to “”
(Q0~Q3=“L”) by a high at the CLEAR input regardless of
other inputs.
All inputs are equipped with protection circuits against
static discharge or transient excess voltage.
Truth Table
X:
Don’t Care
IEC Logic Symbol
1
2
3
4
5
6
7
14
13
12
11
10
9
8
V
CC
2CK
2CLR
2Q
A
2Q
B
2Q
C
2Q
D
1CK
1CLR
1Q
A
1Q
B
1Q
C
1Q
D
GND
(TOP VIEW)
INPUTS
OUTPUTS
CK
CLR
QA
QB
QC
QD
X
H
L
L
L
L
L
COUNT UP
L
NO CHANGE
(2)
(1)
1CLR
1CK
CT=0
(3)
(4)
(5)
(6)
(11)
1QA
1QB
1QC
1QD
2QA
2QB
2QC
2QD
0
CTRDIV16
+
3
CT
(12)
(13)
2CLR
2CK
(10)
(9)
(8)