74F779 8-Bit Bidirectional Binary Counter with 3-STATE Outputs
April 1988
Revised March 2000
74F779
8-Bit Bidirectional Binary Counter with 3-STATE Outputs
General Description
The 74F779 is a fully synchronous 8-stage up/down
counter with multiplexed 3-STATE I/O ports for bus-ori-
ented applications. All control functions (hold, count up,
count down, synchronous load) are controlled by two mode
pins (S
0
, S
1
). The device also features carry lookahead for
easy cascading. All state changes are initiated by the rising
edge of the clock.
Features
s
Multiplexed 3-STATE I/O ports
s
Built-in lookahead carry capability
s
Count frequency 100 MHz typ
s
Supply current 80 mA typ
s
Available in SOIC (300 mil only)
Ordering Code:
Order Number
74F779SC
74F779PC
Package Number
M16B
N16E
Package Description
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Logic Symbol
Connection Diagram
© 2000 Fairchild Semiconductor Corporation
DS009593
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74F779
Unit Loading/Fan Out
Pin Names
I/O
0
–I/O
7
S
0
, S
1
OE
CET
CP
TC
Data Inputs
Data Outputs
Select Inputs
Output Enable Input (Active LOW)
Count Enable Trickle Input (Active LOW)
Clock Pulse Input (Active Rising Edge)
Terminal Count Output (Active LOW)
Description
U.L.
HIGH/LOW
0.25/0.33
75/15 (12.5)
0.25/0.33
0.25/0.33
0.25/0.33
0.25/0.33
25/12.5
Input I
IH
/I
IL
Output I
OH
/I
OL
5
µA/−0.2
mA
−3
mA/24 mA (20 mA)
5
µA/−0.2
mA
5
µA/−0.2
mA
5
µA/−0.2
mA
5
µA/−0.2
mA
−1
mA/20 mA
Function Table
S
1
X
X
L
(Not LL)
H
L
L
H
S
0
X
X
L
CET
X
X
X
H
L
L
OE
H
L
H
X
X
X
CP
X
Function
I/O
0
to I/O
7
in High Z
Flip-Flop Outputs Appear on I/O Lines
Parallel Load All Flip-Flops
Hold (TC Held HIGH)
Count Up
Count Down
H
=
HIGH Voltage Level
L
=
LOW Voltage Level
X
=
Immaterial
=
LOW-to-HIGH Clock Transition
(Not LL) means S
0
and S
1
should never both be LOW level at the same time.
X
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2
74F779
Logic Diagram
Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.
3
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74F779
Absolute Maximum Ratings
(Note 1)
Storage Temperature
Ambient Temperature under Bias
Junction Temperature under Bias
V
CC
Pin Potential to Ground Pin
Input Voltage (Note 2)
Input Current ((Note 2)
Voltage Applied to Output
in HIGH State (with V
CC
=
0V)
Standard Output
3-STATE Output
Current Applied to Output
in LOW State (Max)
ESD Last Passing Voltage (Min)
twice the rated I
OL
(mA)
4000V
−0.5V
to V
CC
−0.5V
to
+5.5V
−65°C
to
+150°C
−55°C
to
+125°C
−55°C
to
+150°C
−0.5V
to
+7.0V
−0.5V
to
+7.0V
−30
mA to
+5.0
mA
Recommended Operating
Conditions
Free Air Ambient Temperature
Supply Voltage
0°C to
+70°C
+4.5V
to
+5.5V
Note 1:
Absolute maximum ratings are values beyond which the device
may be damaged or have its useful life impaired. Functional operation
under these conditions is not implied.
Note 2:
Either voltage limit or current limit is sufficient to protect inputs.
DC Electrical Characteristics
Symbol
V
IH
V
IL
V
CD
V
OH
V
OL
I
IH
I
BVI
I
BVIT
I
CEX
V
ID
I
OD
I
ZZ
I
IL
I
IH
+
I
OZH
I
IL
+
I
OZL
I
OS
I
CCH
I
CCL
I
CCZ
Parameter
Input HIGH Voltage
Input LOW Voltage
Input Clamp Diode Voltage
Output HIGH
Voltage
Output LOW
Voltage
Input HIGH Current
Input HIGH Current
Breakdown Test
Input HIGH Current
Breakdown (I/O)
Output HIGH
Leakage Current
Input Leakage
Test
Output Leakage
Circuit Current
Bus Drainage Test
Input LOW Current
Output Leakage Current
Output Leakage Current
Output Short-Circuit Current
Power Supply Current
Power Supply Current
Power Supply Current
−60
4.75
3.75
500
−0.2
70
−200
−150
90
105
110
10% V
CC
5% V
CC
10% V
CC
5% V
CC
2.4
2.7
0.5
0.5
5.0
7.0
0.5
50
Min
2.0
0.8
−1.2
Typ
Max
Units
V
V
V
V
V
µA
µA
mA
µA
V
µA
µA
mA
µA
µA
mA
mA
mA
mA
Min
Min
Min
Max
Max
Max
Max
0.0
0.0
0.0
Max
Max
Max
Max
Max
Max
Max
V
CC
Conditions
Recognized as a HIGH Signal
Recognized as a LOW Signal
I
IN
= −18
mA
I
OH
= −3
mA
I
OL
=
20 mA
I
OL
=
20 mA
V
IN
=
2.7V (Non-I/O Pins)
V
IN
=
7.0V (Non-I/O Pins)
V
IN
=
5.5V (I/O
n
)
V
OUT
=
V
CC
I
ID
=
1.9
µA
All other pins grounded
V
IOD
=
150 mV
All other pins grounded
V
OUT
=
5.25V
V
IN
=
0.5V (Non I/O Pins)
V
OUT
=
2.7V (I/O
n
)
V
OUT
=
0.5V (I/O
n
)
V
OUT
=
0V
V
O
=
HIGH
V
O
=
LOW
V
O
=
HIGH Z
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4
74F779
AC Electrical Characteristics
T
A
= +25°C
Symbol
Parameter
Min
f
MAX
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
t
PZH
t
PZL
t
PHZ
t
PLZ
Maximum Clock Frequency
Propagation Delay
CP to I/O
n
Propagation Delay
CP to TC
Propagation Delay
CET to TC
Propagation Delay
SN to TC
Output Enable Time
OE to I/O
n
Output Disable Time
OE to I/O
n
100
3.0
5.0
5.0
5.0
2.5
4.5
3.5
3.5
3.0
5.0
1.0
1.0
V
CC
= +5.0V
C
L
=
50 pF
Typ
105
5.0
7.5
7.5
9.3
3.8
6.1
6.5
7.5
5.0
8.0
4.0
3.7
8.0
11.0
9.0
10.5
5.5
8.0
12.0
12.0
7.0
10.0
6.5
6.5
Max
T
A
=
0°C to
+70°C
V
CC
= +5.0V
C
L
=
50 pF
Min
90
3.0
5.0
5.0
5.0
2.5
4.5
3.5
3.5
3.0
5.0
1.0
1.0
8.5
11.0
10.0
11.5
6.0
8.5
13.0
13.0
8.0
10.5
7.0
7.0
ns
ns
Max
Units
ns
ns
ns
ns
AC Operating Requirements
T
A
= +25°C
Symbol
Parameter
V
CC
= +5.0V
Min
t
S
(H)
t
S
(L)
t
H
(H)
t
H
(L)
t
S
(H)
t
S
(L)
t
H
(H)
t
H
(L)
t
S
(H)
t
S
(L)
t
H
(H)
t
H
(L)
t
W
(H)
t
W
(L)
Setup Time
I/O
n
to CP
Hold Time
I/O
n
to CP
Setup Time
S
n
to CP
Hold Time
S
n
to CP
Setup Time
CET to CP
Hold Time
CET to CP
Clock Pulse Width
HIGH or LOW
5.0
5.0
0.0
0.0
9.5
9.5
0.0
0.0
7.0
7.0
0.0
0.0
4.0
4.0
Max
T
A
=
0°C to
+70°C
V
CC
= +5.0V
Min
5.0
5.0
0.0
0.0
10.0
10.0
0.0
0.0
7.0
7.0
0.0
0.0
4.0
4.0
Max
ns
ns
ns
ns
ns
Units
ns
ns
5
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