Data sheet acquired from Harris Semiconductor
SCHS221
CD74HC40103,
CD74HCT40103
High Speed CMOS Logic
8-Stage Synchronous Down Counters
Description
The Harris CD74HC40103 and CD74HCT40103 are
manufactured with high speed silicon gate technology and
consist of an 8-stage synchronous down counter with a
single output which is active when the internal count is zero.
The 40103 contains a single 8-bit binary counter. Each has
control inputs for enabling or disabling the clock, for clearing
the counter to its maximum count, and for presetting the
counter either synchronously or asynchronously. All control
inputs and the TC output are active-low logic.
In normal operation, the counter is decremented by one
count on each positive transition of the CLOCK (CP).
Counting is inhibited when the TE input is high. The TC
output goes low when the count reaches zero if the TE input
is low, and remains low for one full clock period.
When the PE input is low, data at the P0-P7 inputs are
clocked into the counter on the next positive clock transition
regardless of the state of the TE input. When the PL input is
low, data at the P0-P7 inputs are asynchronously forced into
the counter regardless of the state of the PE, TE, or CLOCK
inputs. Input P0-P7 represent a single 8-bit binary word for
the 40103. When the MR input is low, the counter is
asynchronously cleared to its maximum count of 255
10
,
regardless of the state of any other input. The precedence
relationship between control inputs is indicated in the truth
table.
If all control inputs except TE are high at the time of zero
count, the counters will jump to the maximum count, giving a
counting sequence of 100 or 256 clock pulses long.
The 40103 may be cascaded using the TE input and the TC
output, in either a synchronous or ripple mode. These
circuits possess the the low power consumption usually
associated with CMOS circuitry, yet have speeds
comparable to low power Schottky TTL circuits and can drive
up to 10 LSTTL loads.
November 1997
Features
鈥?Synchronous or Asynchronous Preset
鈥?Cascadable in Synchronous or Ripple Mode
鈥?Fanout (Over Temperature Range)
- Standard Outputs . . . . . . . . . . . . . . . 10 LSTTL Loads
- Bus Driver Outputs . . . . . . . . . . . . . 15 LSTTL Loads
鈥?Wide Operating Temperature Range . . . -55
o
C to 125
o
C
鈥?Balanced Propagation Delay and Transition Times
鈥?Signi铿乧ant Power Reduction Compared to LSTTL
Logic ICs
鈥?HC Types
- 2V to 6V Operation
- High Noise Immunity: N
IL
= 30%, N
IH
= 30% of V
CC
at V
CC
= 5V
鈥?HCT Types
- 4.5V to 5.5V Operation
- Direct LSTTL Input Logic Compatibility,
V
IL
= 0.8V (Max), V
IH
= 2V (Min)
- CMOS Input Compatibility, I
l
鈮?/div>
1碌A at V
OL
, V
OH
[ /Title
(CD74H
C40103,
CD74H
CT4010
3)
/Sub-
ject
(High
Speed
CMOS
Logic 8-
Ordering Information
PART NUMBER
CD74HC40103E
CD74HCT40103E
CD74HC40103M
CD74HCT40103M
NOTES:
1. When ordering, use the entire part number. Add the suf铿亁 96 to
obtain the variant in the tape and reel.
2. Wafer or 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.
TEMP. RANGE (
o
C)
-55 to 125
-55 to 125
-55 to 125
-55 to 125
PACKAGE
16 Ld PDIP
16 Ld PDIP
16 Ld SOIC
16 Ld SOIC
PKG.
NO.
E16.3
E16.3
M16.15
M16.15
CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.
Copyright
漏
Harris Corporation 1997
File Number
1596.1
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