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54AC163 •54ACT163
Synchronous Presettable Binary Counter
General Description
The ’AC/’ACT163 are high-speed synchronous modulo-16
binary counters. They are synchronously presettable for ap-
plication in programmable dividers and have two types of
Count Enable inputs plus a Terminal Count output for versa-
tility in forming synchronous multistage counters. The ’AC/
’ACT163 has a Synchronous Reset input that overrides
counting and parallel loading and allows the outputs to be si-
multaneously reset on the rising edge of the clock.
Features
nI
CC
reduced by 50%
nSynchronous counting and loading
nHigh-speed synchronous expansion
nTypical count rate of 125 MHz
nOutputs source/sink 24 mA
n’ACT163 has TTL-compatible inputs
nStandard Microcircuit Drawing (SMD)
— ’AC163: 5962-89582
— ’ACT163: 5962-91723
Logic Symbols Pin
Names Description
CEP Count Enable Parallel Input
CET Count Enable Trickle Input
CP Clock Pulse Input
SR Synchronous Reset Input
P
0
–P
3
Parallel Data Inputs
PE Parallel Enable Input
Q
0
–Q
3
Flip-Flop Outputs
TC Terminal Count Output
FACT™is a trademark of Fairchild Semiconductor Corporation.
DS100275-1
IEEE/IEC
DS100275-2
November 1998
54AC163
•
54ACT163 Synchronous Presettable Binary Counter
© 1998 National Semiconductor Corporation DS100275 www.national.com
Connection Diagrams
Functional Description
The ’AC/’ACT163 counts in modulo-16 binary sequence.
From state 15 (HHHH) it increments to state 0 (LLLL). The
clock inputs of all flip-flops are driven in parallel through a
clock buffer. Thus all changes of the Q outputs occur as a re-
sult of, and synchronous with, the LOW-to-HIGH transition of
the CP input signal. The circuits have four fundamental
modes of operation, in order of precedence: synchronous re-
set, parallel load, count-up and hold. Four control
inputs—Synchronous Reset (SR), Parallel Enable (PE),
Count Enable Parallel (CEP) and Count Enable Trickle
(CET)—determine the mode of operation, as shown in the
Mode Select Table. A LOW signal on SR overrides counting
and parallel loading and allows all outputs to go LOW on the
next rising edge of CP.ALOW signal on PE overrides count-
ing and allows information on the Parallel Data (P
n
) inputs to
be loaded into the flip-flops on the next rising edge of CP.
With PE and SR HIGH, CEP and CET permit counting when
both are HIGH. Conversely, a LOW signal on either CEP or
CET inhibits counting.
The ’AC/’ACT163 uses D-type edge-triggered flip-flops and
changing the SR, PE, CEP and CET inputs when the CP is
in either state does not cause errors, provided that the rec-
ommended setup and hold times, with respect to the rising
edge of CP, are observed.
The Terminal Count (TC) output is HIGH when CET is HIGH
and counter is in state 15. To implement synchronous multi-
stage counters, the TC outputs can be used with the CEP
and CET inputs in two different ways.
Figure 1
shows the connections for simple ripple carry, in
which the clock period must be longer than the CP to TC de-
lay of the first stage, plus the cumulative CET to TC delays of
the intermediate stages, plus the CET to CP setup time of
the last stage. This total delay plus setup time sets the upper
limit on clock frequency. For faster clock rates, the carry loo-
kahead connections shown in
Figure 2
are recommended. In
this scheme the ripple delay through the intermediate stages
commences with the same clock that causes the first stage
to tick over from max to min in the Up mode, or min to max
in the Down mode, to start its final cycle. Since this final
cycle takes 16 clocks to complete, there is plenty of time for
the ripple to progress through the intermediate stages. The
critical timing that limits the clock period is the CP to TC de-
lay of the first stage plus the CEP to CP setup time of the last
stage. The TC output is subject to decoding spikes due to in-
ternal race conditions and is therefore not recommended for
use as a clock or asynchronous reset for flip-flops, registers
or counters.
Logic Equations: Count Enable =CEP •CET •PE
TC =Q
0
•Q
1
•Q
2
•Q
3
•CET
Mode Select Table
SR PE CET CEP Action on the Rising
Clock Edge (N)
L X X X Reset (Clear)
H L X X Load (P
n
→Q
n
)
H H H H Count (Increment)
H H L X No Change (Hold)
H H X L No Change (Hold)
H=HIGH Voltage Level
L=LOW Voltage Level
X=Immaterial
State Diagram
Pin Assignment
for DIP and Flatpak
DS100275-3
Pin Assignment
for LCC
DS100275-4
DS100275-5
www.national.com 2
State Diagram (Continued)
DS100275-8
FIGURE 1.
DS100275-9
FIGURE 2.
www.national.com3
Block Diagram
DS100275-6
Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.
www.national.com 4
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage (V
CC
) −0.5V to +7.0V
DC Input Diode Current (I
IK
)
V
I
=−0.5V −20 mA
V
I
=V
CC
+ 0.5V +20 mA
DC Input Voltage (V
I
) −0.5V to V
CC
+ 0.5V
DC Output Diode Current (I
OK
)
V
O
=−0.5V −20 mA
V
O
=V
CC
+ 0.5V +20 mA
DC Output Voltage (V
O
) −0.5V to V
CC
+ 0.5V
DC Output Source
or Sink Current (I
O
)±50 mA
DC V
CC
or Ground Current
per Output Pin (I
CC
or I
GND
)±50 mA
Storage Temperature (T
STG
) −65˚C to +150˚C
Junction Temperature (T
J
)
CDIP 175˚C
Recommended Operating
Conditions
Supply Voltage (V
CC
)
’AC 2.0V to 6.0V
’ACT 4.5V to 5.5V
Input Voltage (V
I
) 0VtoV
CC
Output Voltage (V
O
) 0VtoV
CC
Operating Temperature (T
A
)
54AC/ACT −55˚C to +125˚C
Minimum Input Edge Rate (∆V/∆t)
’AC Devices
V
IN
from 30%to 70%of V
CC
V
CC
@3.3V, 4.5V, 5.5V 125 mV/ns
Minimum Input Edge Rate (∆V/∆t)
’ACT Devices
V
IN
from 0.8V to 2.0V
V
CC
@4.5V, 5.5V 125 mV/ns
Note 1: Absolute maximum ratings are those values beyond which damage
to the device may occur. The databook specifications should be met, without
exception, to ensure that the system design is reliable over its power supply,
temperature, and output/input loading variables. National does not recom-
mend operation of FACT™circuits outside databook specifications.
DC Characteristics for ’AC Family Devices
54AC
Symbol Parameter V
CC
T
A
=Units Conditions
(V) −55˚C to +125˚C
Guaranteed
Limits
V
IH
Minimum High Level 3.0 2.1 V
OUT
=0.1V
Input Voltage 4.5 3.15 V or V
CC
− 0.1V
5.5 3.85
V
IL
Maximum Low Level 3.0 0.9 V
OUT
=0.1V
Input Voltage 4.5 1.35 V or V
CC
− 0.1V
5.5 1.65
V
OH
Minimum High Level 3.0 2.9 I
OUT
=−50 µA
Output Voltage 4.5 4.4 V
5.5 5.4 (Note 2)
V
IN
=V
IL
or V
IH
3.0 2.4 I
OH
= −12 mA
4.5 3.7 V I
OH
= −24 mA
5.5 4.7 I
OH
= −24 mA
V
OL
Maximum Low Level 3.0 0.1 I
OUT
=50 µA
Output Voltage 4.5 0.1 V
5.5 0.1 (Note 2)
V
IN
=V
IL
or V
IH
3.0 0.50 I
OL
=12mA
4.5 0.50 V I
OL
=24mA
5.5 0.50 I
OL
=24mA
I
IN
Maximum Input 5.5 ±1.0 µA V
I
=V
CC
, GND
Leakage Current
I
OLD
Minimum Dynamic
Output Current (Note 3) 5.5 50 mA V
OLD
=1.65V Max
I
OHD
5.5 −50 mA V
OHD
=3.85V Min
www.national.com5
DC Characteristics for ’AC Family Devices (Continued)
54AC
Symbol Parameter V
CC
T
A
=Units Conditions
(V) −55˚C to +125˚C
Guaranteed
Limits
I
CC
Maximum Quiescent 5.5 160 µA V
IN
=V
CC
Supply Current or GND
Note 2: All outputs loaded; thresholds on input associated with output under test.
Note 3: Maximum test duration 2.0 ms, one output loaded at a time.
Note 4: IIN and ICC @3.0V are guaranteed to be less than or equal to the respective limit @5.5V VCC.
ICC for 54AC @25˚C is identical to 74AC @25˚C.
DC Characteristics for ’ACT Family Devices
54ACT
Symbol Parameter V
CC
T
A
=Units Conditions
(V) −55˚C to +125˚C
Guaranteed
Limits
V
IH
Minimum High Level 4.5 3.0 V V
OUT
=0.1V
Input Voltage (Note 7) 5.5 3.0 or V
CC
− 0.1V
V
IL
Maximum Low Level 4.5 0.8 V V
OUT
=0.1V
Input Voltage 5.5 0.8 or V
CC
− 0.1V
V
OH
Minimum High Level 4.5 4.4 V I
OUT
=−50 µA
Output Voltage 5.5 5.4 (Note 5)
V
IN
=V
IL
or 3.0V
4.5 3.70 V I
OH
= −24 mA
5.5 4.70 I
OH
= −24 mA
V
OL
Maximum Low Level 4.5 0.1 V I
OUT
=50 µA
Output Voltage 5.5 0.1 (Note 5)
V
IN
=V
IL
or V
IH
4.5 0.50 V I
OL
=24mA
5.5 0.50 I
OL
=24mA
I
IN
Maximum Input 5.5 ±1.0 µA V
I
=V
CC
, GND
Leakage Current
I
CCT
Maximum 5.5 1.6 mA V
I
=V
CC
− 2.1V
I
CC
/Input
I
OLD
Minimum Dynamic
Output Current (Note 6) 5.5 50 mA V
OLD
=1.65V Max
I
OHD
5.5 −50 mA V
OHD
=3.85V Min
I
CC
Maximum Quiescent 5.5 80.0 µA V
IN
=V
CC
Supply Current or GND
Note 5: All outputs loaded; thresholds on input associated with output under test.
Note 6: Maximum test duration 2.0 ms, one output loaded at a time.
Note 7: For dynamic operation, a VIH level between 2.0 and 3.0V may be recognized by this device as a high logic level input. For static operation, a VIH ≥2.0V will
be recognized by this device as a high logic level input. Users are cautioned to verify that this will not affect their system.
www.national.com 6
AC Electrical Characteristics
54AC
V
CC
T
A
=−55˚C
Symbol Parameter (V) to +125˚C Units
(Note 8) C
L
=50 pF
Min Max
f
max
Maximum Clock 3.3 55 MHz
Frequency 5.0 90
t
PLH
Propagation Delay, CP to Q
n
3.3 1.0 13.5 ns
(PE Input HIGH or LOW) 5.0 1.5 9.5
t
PHL
Propagation Delay, CP to Q
n
3.3 1.0 12.5 ns
(PE Input HIGH or LOW) 5.0 1.5 9.5
t
PLH
Propagation Delay 3.3 1.0 16.5 ns
CP to TC 5.0 1.5 11.0
t
PHL
Propagation Delay 3.3 1.0 15.0 ns
CP to TC 5.0 1.5 11.0
t
PLH
Propagation Delay 3.3 1.0 11.0 ns
CET to TC 5.0 1.5 7.5
t
PHL
Propagation Delay 3.3 1.0 12.0 ns
CET to TC 5.0 1.5 9.0
Note 8: Voltage Range 3.3 is 3.3V ±0.3V
Voltage Range 5.0 is 5.0V ±0.5V
AC Operating Requirements
54AC
V
CC
T
A
=−55˚C
Symbol Parameter (V) to +125˚C Units
(Note 9) C
L
=50 pF
Guaranteed Minimum
t
s
Setup Time, HIGH or LOW 3.3 17.0 ns
P
n
to CP 5.0 11.0
t
h
Hold Time, HIGH or LOW 3.3 −0.5 ns
P
n
to CP 5.0 0
t
s
Setup Time, HIGH or LOW 3.3 17.0 ns
SR to CP 5.0 12.0
t
h
Hold Time, HIGH or LOW 3.3 −0.5 ns
SR to CP 5.0 0
t
s
Setup Time, HIGH or LOW 3.3 16.0 ns
PE to CP 5.0 9.5
t
h
Hold Time, HIGH or LOW 3.3 −0.5 ns
PE to CP 5.0 0
t
s
Setup Time, HIGH or LOW 3.3 8.0 ns
CEP or CET to CP 5.0 5.5
t
h
Hold Time, HIGH or LOW 3.3 0 ns
CEP or CET to CP 5.0 0.5
t
w
Clock Pulse Width (Load) 3.3 5.0 ns
HIGH or LOW 5.0 5.0
t
w
Clock Pulse Width (Count) 3.3 5.0 ns
HIGH or LOW 5.0 5.0
Note 9: Voltage Range 3.3 is 3.3V ±0.3V
Voltage Range 5.0 is 5.0V ±0.5V
www.national.com7
AC Electrical Characteristics
54ACT
V
CC
T
A
=−55˚C
Symbol Parameter (V) to +125˚C Units
(Note 10) C
L
=50 pF
Min Max
f
max
Maximum Clock 5.0 90 MHz
Frequency
t
PLH
Propagation Delay, CP to Q
n
5.0 1.5 10.5 ns
(PE Input HIGH or LOW)
t
PHL
Propagation Delay, CP to Q
n
5.0 1.5 10.5 ns
(PE Input HIGH or LOW)
t
PLH
Propagation Delay 5.0 1.5 12.5 ns
CP to TC
t
PHL
Propagation Delay 5.0 1.5 13.0 ns
CP to TC
t
PLH
Propagation Delay 5.0 1.5 9.5 ns
CET to TC
t
PHL
Propagation Delay 5.0 1.5 9.5 ns
CET to TC
Note 10: Voltage Range 5.0 is 5.0V ±0.5V
AC Operating Requirements
54ACT
V
CC
T
A
=−55˚C
Symbol Parameter (V) to +125˚C Units
(Note 11) C
L
=50 pF
Guaranteed
Minimum
t
s
Setup Time, HIGH or LOW 5.0 13.5 ns
P
n
to CP
t
h
Hold Time, HIGH or LOW 5.0 0.5 ns
P
n
to CP
t
s
Setup Time, HIGH or LOW 5.0 13.5 ns
SR to CP
t
h
Hold Time, HIGH or LOW 5.0 0.0 ns
SR to CP
t
s
Setup Time, HIGH or LOW 5.0 11.5 ns
PE to CP
t
h
Hold Time, HIGH or LOW 5.0 0.0 ns
PE to CP
t
s
Setup Time, HIGH or LOW 5.0 7.0 ns
CEP or CET to CP
t
h
Hold Time, HIGH or LOW 5.0 0.5 ns
CEP or CET to CP
t
w
Clock Pulse Width (Load) 5.0 5.0 ns
HIGH or LOW
t
w
Clock Pulse Width 5.0 5.0 ns
(Count) HIGH or LOW
Note 11: Voltage Range 5.0 is 5.0V ±0.5V
www.national.com 8
Capacitance
Symbol Parameter Typ Units Conditions
C
IN
Input Capacitance 4.5 pF V
CC
=OPEN
C
PD
Power Dissipation 45.0 pF V
CC
=5.0V
Capacitance
www.national.com9
10
Physical Dimensions inches (millimeters) unless otherwise noted
20 Terminal Ceramic Leadless Chip Carrier (L)
NS Package Number E20A
16-Lead Ceramic Dual-In-Line Package (D)
NS Package Number J16A
www.national.com11
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
LIFE SUPPORT POLICY
NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DE-
VICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMI-
CONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or sys-
tems which, (a) are intended for surgical implant into
the body, or (b) support or sustain life, and whose fail-
ure to perform when properly used in accordance
with instructions for use provided in the labeling, can
be reasonably expected to result in a significant injury
to the user.
2. A critical component in any component of a life support
device or system whose failure to perform can be rea-
sonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
National Semiconductor
Corporation
Americas
Tel: 1-800-272-9959
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Email: support@nsc.com
www.national.com
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Fax: 81-3-5620-6179
16-Lead Ceramic Flatpak (F)
NS Package Number W16A
54AC163
•
54ACT163 Synchronous Presettable Binary Counter
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.