Page 1
SYNCHRONOUS PRESETTABLE 4-BIT COUNTER
■ HIGHSPEED:
f
=125MHz(TYP.)at VCC=5V
MAX
■ LOW POWER DISSIPATION:
=8 µA (MAX.) at TA=25oC
I
CC
■ HIGHNOISEIMMUNITY:
V
NIH=VNIL
■ 50Ω TRANSMISSIONLINEDRIVING
CAPABILITY
■ SYMMETRICALOUTPUTIMPEDANCE:
|I
|=IOL=24mA(MIN)
OH
■ BALANCEDPROPAGATIONDELAYS:
t
≅ t
PLH
■ OPERATINGVOLTAGERANGE:
V
(OPR)= 2Vto 6V
CC
■ PINANDFUNCTIONCOMPATIBLEWITH
74SERIES161
■ IMPROVEDLATCH-UPIMMUNITY
DESCRIPTION
The AC161 is a high-speed CMOS
SYNCRONOUS PRESETTABLE COUNTER
fabricated with sub-micron silicon gate and
double-layermetal wiring C
ideal for low power applications mantaining high
speed operation similar to eqivalent Bipolar
Schottky TTL. It is a 4 bit binary counter with
AsynchronousClear.
The circuit have four fundamental modes of
operation, in order of preference: synchronous
=28%VCC(MIN.)
PHL
2
MOS technology.It is
74AC161
B
(PlasticPackage)
(Micro Package)
ORDERCODES :
74AC161B 74AC161M
reset, parallel load, count-up and hold. Four
control inputs, Master Reset (CLEAR), Parallel
Enable Input (LOAD), Count Enable Input (PE)
and Count Enable Carry Input (TE), determine
the mode of operation as shown in the Truth
Table. A LOW signal on CLEAR overrides
counting and parallel loading and sets all outputs
on LOW state. A LOW signal on LOAD overrides
counting and allows information on Parallel Data
Qn inputs to be loaded into the flip-flops on the
next rising edge of CLOCK. With LOAD and
CLEAR, PE and TE permit counting when both
are HIGH. Conversely, a LOW signal on either
PE and TE inhibitscounting.
All inputs and outputs are equipped with
protection circuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.
M
PIN CONNECTION AND IECLOGIC SYMBOLS
December 1998
1/12
Page 2
74AC161
INPUT AND OUTPUTEQUIVALENTCIRCUIT
PIN DESCRIPTION
PI N No SYM BO L NAM E AND FU NCTION
1 CLEAR MasterReset
2 CLOCK ClockInput(LOW-to-HIGH,
Edge-Triggered)
3, 4, 5, 6 A, B, C, D Data Inputs
7 PE CountEnable Input
10 TE CountEnable CarryInput
9 LOAD ParallelEnableInput
14, 13,12,11QA to QD Flip-Flop Outpus
15 CARRY
OUT
8 GND Ground(0V)
16 V
CC
Terminal CountOutput
PositiveSupply Voltage
TRUTH TABLE
INPUTS OUTPUTS FUNCTION
CLEAR LOAD PE TE CLOCK QA QB QC QD
LXXXXLLLL RESET TO ”0”
H L X X A B C D PRESET DATA
H H X L NO CHANGE NO COUNT
H H L X NO CHANGE NO COUNT
H H H H COUNT UP COUNT
H X X X NO CHANGE NO COUNT
NOTE: X:Don’tCare
A,B, C,D: Logiclevelofdatainput
CARRYOUT=TE• QA• QB • QC • QD
LOGICDIAGRAMS
2/12
Page 3
TIMINGCHART
74AC161
3/12
Page 4
74AC161
ABSOLUTE MAXIMUM RATINGS
Symb o l Para met er Val u e Uni t
V
V
V
I
I
OK
I
or I
I
CC
T
T
AbsoluteMaximumRatingsarethosevaluesbeyond whichdamage tothedevice mayoccur.Functionaloperation underthesecondition isnotimplied.
RECOMMENDEDOPERATINGCONDITIONS
Symb o l Para met er Value Un it
V
V
V
T
dt/dv InputRiseand FallTime V
1)VINfrom30%to70%ofV
SupplyVoltage -0.5 to +7 V
CC
DC InputVoltage -0.5 to VCC+ 0.5 V
I
DC OutputVoltage -0.5 to VCC+ 0.5 V
O
DC InputDiode Current ± 20 mA
IK
DC OutputDiode Current ± 20 mA
DC OutputCurrent
O
DC VCCorGround Current
GND
Storage Temperature -65 to +150
stg
LeadTemperature (10 sec) 300
L
SupplyVoltage 2 to 6 V
CC
InputVoltage 0 to V
I
OutputVoltage 0 to V
O
OperatingTemperature: -40 to +85
op
=3.0,4.5 or 5.5V(note1) 8 ns/V
CC
CC
50 mA
±
300 mA
±
CC
CC
o
C
o
C
V
V
o
C
4/12
Page 5
74AC161
DC SPECIFICATIONS
Symbol Parameter Test Conditions Value Unit
T
V
CC
(V)
HighLevelInputVoltage 3.0 VO= 0.1V or
V
IH
4.5 3.15 2.25 3.15
-0.1 V
V
CC
5.5 3.85 2.75 3.85
LowLevel InputVoltage 3.0 VO= 0.1V or
V
IL
4.5 2.25 1.35 1.35
V
-0.1 V
CC
5.5 2.75 1.65 1.65
HighLevelOutputVoltage 3.0
V
OH
4.5 I
5.5 I
V
V
3.0 I
4.5 I
5.5 I
LowLevel OutputVoltage 3.0
V
OL
4.5 I
5.5 I
V
V
3.0 I
4.5 I
5.5 I
InputLeakage Current 5.5 VI=VCCor GND ±0.1 ±1 µA
I
I
Quiescent SupplyCurrent 5.5 VI=VCCor GND 8 80
I
CC
Dynamic OutputCurrent
I
OLD
OHD
(note 1, 2)
I
1) Maximum test duration 2ms,oneoutput loaded attime
2)Incident waveswitchingisguaranteed ontransmissionlines withimpedancesaslowas 50 Ω.
(*)Alloutputs loaded.
5.5 V
V
IO=-50 µA 2.9 2.99 2.9
(*)
I
IH
V
IL
=-50 µA 4.4 4.49 4.4
O
=
=-50 µA 5.4 5.49 5.4
or
O
=-12 mA 2.56 2.46
O
=-24 mA 3.86 3.76
O
=-24 mA 4.86 4.76
O
IO=50 µA 0.002 0.1 0.1
(*)
I
IH
V
OLD
OHD
IL
=50 µA 0.001 0.1 0.1
O
=
=50µA 0.001 0.1 0.1
or
O
=12 mA 0.36 0.44
O
=24 mA 0.36 0.44
O
=24 mA 0.36 0.44
O
= 1.65 V max 75 mA
= 3.85 V min -75 mA
=25oC -40 to 85oC
A
Min. Typ. Max. Min. Max.
2.1 1.5 2.1
1.5 0.9 0.9
µ
V
V
V
V
A
5/12
Page 6
74AC161
AC ELECTRICAL CHARACTERISTICS
= 50 pF, RL= 500 Ω, Inputtr=tf=3 ns)
(C
L
Symbol Parameter Test Condition Value Unit
t
PropagationDelay Time
PLH
t
CKto Q
PHL
PropagationDelay Time
t
PLH
t
CKto CARRYOUT
PHL
PropagationDelay Time
t
PLH
t
TEto CARRY OUT
PHL
PropagationDelay Time
t
PHL
CLRto Q
PropagationDelay Time
t
PHL
CLRto CARRY OUT
CLRpulse Width,LOW
t
wL
(LOAD)
CKpulse Width
t
w
HIGHor LOW
SetupTime HIGH orLOW
t
s
(INPUTto CLOCK)
HoldTimeHIGH or LOW
t
h
(INPUTto CLOCK)
SetupTime HIGH orLOW
t
s
(CLEARto CLOCK)
HoldTimeHIGH or LOW
t
h
(CLEARto CLOCK)
SetupTime HIGH orLOW
t
s
(PEor TE to CLOCK)
HoldTimeHIGH or LOW
t
h
(PEor TE to CLOCK)
REM
RecoveryTime
t
CLRto CLOCK
f
(*) Voltagerangeis3.3V ± 0.3V
(**) Voltagerangeis 5V±0.5V
MaximumClock Frequency 3.3
MAX
V
(V)
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
5.0
CC
(*)
(**)
(*)
(**)
(*)
(**)
(*)
(**)
(*)
(**)
(*)
(**)
(*)
(**)
(*)
(**)
(*)
(**)
(*)
(**)
(*)
(**)
(*)
(**)
(*)
(**)
(*)
(**)
(*)
(**)
T
=25oC -40 to 85oC
A
Min. Typ. Max. Min. Max.
7.0 12.0 13.0
5.0 9.0 10.0
8.5 14.0 15.0
6.0 10.0 11.0
5.5 9.5 11.0
3.5 6.5 7.5
6.5 12.0 13.0
5.5 9.0 10.0
7.0 12.0 13.0
5.5 9.5 10.0
3.0 5.5 7.5
2.5 4.5 6.0
2.0 3.5 4.0
2.0 3.0 3.5
4.0 13.5 16.0
1.5 8.5 10.5
-1.0 -1.0 0.5
-0.5 0.5 1.0
3.0 11.5 14.0
2.0 7.5 8.5
-2.5 0 0
-2.0 0.5 1.0
3.0 6.0 7.0
2.0 4.5 5.0
-3.5 0 0
-2.0 0 0.5
-1.0 0 0.5
-0.5 0.5 1.0
70 110 60
110 165 95
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
MHz
CAPACITIVE CHARACTERISTICS
Symbol Parameter Test Conditions Value Unit
V
CC
(V)
InputCapacitance 5.0 4.5 pF
C
IN
C
PD
Power Dissipation
5.0 fIN= 10 MHz 45 pF
Capacitance (note1)
1)CPDisdefinedasthevalueoftheIC’sinternalequivalentcapacitance whichis calculated fromtheoperatingcurrent consumption without load. (Referto
TestCircuit).Average opertingcurrent canbeobtainedbythefollowingequation. I
(opr)=CPD• VCC• fIN+ICC/n(percircuit)
CC
6/12
=25oC -40 to 85oC
T
A
Min. Typ. Max. Min. Max.
Page 7
TESTCIRCUIT
CL= 50 pF orequivalent (includes jigand probe capacitance)
R
=500Ωorequivalent
L=R1
R
ofpulsegenerator (typically50Ω)
T=ZOUT
WAVEFORM1: PROPAGATIONDELAYS, COUNT MODE (f=1MHz; 50% duty cycle)
74AC161
7/12
Page 8
74AC161
WAVEFORM2: PROPAGATIONDELAYS CLEAR MODE
(f=1MHz;50% duty cycle)
WAVEFORM3: PROPAGATIONDELAYS PRESET MODE (f=1MHz;50% dutycycle)
8/12
Page 9
74AC161
WAVEFORM4: PROPAGATIONDELAYS COUNTEABLEMODE
(f=1MHz;50% dutycycle)
WAVEFORM5: PROPAGATIONDELAYS CASCADE MODE (f=1MHz; 50%duty cycle)
9/12
Page 10
74AC161
Plastic DIP-16 (0.25) MECHANICAL DATA
DIM.
MIN. TYP. MAX. MIN. TYP. MAX.
a1 0.51 0.020
B 0.77 1.65 0.030 0.065
b 0.5 0.020
b1 0.25 0.010
D 20 0.787
E 8.5 0.335
e 2.54 0.100
e3 17.78 0.700
F 7.1 0.280
I 5.1 0.201
L 3.3 0.130
Z 1.27 0.050
mm inch
10/12
P001C
Page 11
SO-16 MECHANICALDATA
74AC161
DIM.
MIN. TYP. MAX. MIN. TYP. MAX.
A 1.75 0.068
a1 0.1 0.2 0.004 0.007
a2 1.65 0.064
b 0.35 0.46 0.013 0.018
b1 0.19 0.25 0.007 0.010
C 0.5 0.019
c1 45 (typ.)
D 9.8 10 0.385 0.393
E 5.8 6.2 0.228 0.244
e 1.27 0.050
e3 8.89 0.350
F 3.8 4.0 0.149 0.157
G 4.6 5.3 0.181 0.208
L 0.5 1.27 0.019 0.050
M 0.62 0.024
S 8 (max.)
mm inch
P013H
11/12
Page 12
74AC161
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility forthe consequences
of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is
granted by implicationor otherwise under any patent or patent rights of STMicroelectronics. Specification mentioned in this publication are
subject tochange without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products
are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
The ST logo is a registered trademark of STMicroelectronics
1998 STMicroelectronics – Printed in Italy – All Rights Reserved
STMicroelectronics GROUP OF COMPANIES
Australia - Brazil -Canada -China -France - Germany - Italy - Japan -Korea - Malaysia - Malta - Mexico -Morocco - The Netherlands -
Singapore - Spain -Sweden - Switzerland - Taiwan - Thailand - UnitedKingdom -U.S.A.
http://www.st.com
.
12/12
Loading...