74F190PC Fairchild Semiconductor, 74F190PC Datasheet - Page 2

• Manufacturer Part Number: 74F190PC
• Description: IC COUNTER DECADE UP/DOWN 16-DIP
• Manufacturer: Fairchild Semiconductor
• Series: 74Fr

Specifications of 74F190PC

• Logic Type: Counter, Decade
• Direction: Up, Down
• Number Of Elements: 1
• Number Of Bits Per Element: 4
• Timing: Synchronous
• Count Rate: 125MHz
• Trigger Type: Positive Edge
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: 16-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Reset: -
• Other names: 74F190

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Unit Loading/Fan Out
Functional Description
The 74F190 is a synchronous up/down BCD decade
counter containing four edge-triggered flip-flops, with inter-
nal gating and steering logic to provide individual preset,
count-up and count-down operations. It has an asynchro-
nous parallel load capability permitting the counter to be
preset to any desired number. When the Parallel Load (PL)
input is LOW, information present on the Parallel Data
inputs (P
the Q outputs. This operation overrides the counting func-
tions, as indicated in the Mode Select Table. A HIGH signal
on the CE input inhibits counting. When CE is LOW, inter-
nal state changes are initiated synchronously by the LOW-
to-HIGH transition of the clock input. The direction of count-
ing is determined by the U/D input signal, as indicated in
the Mode Select Table, CE and U/D can be changed with
the clock in either state, provided only that the recom-
mended setup and hold times are observed.
Two types of outputs are provided as overflow/underflow
indicators. The Terminal Count (TC) output is normally
LOW and goes HIGH when a circuit reaches zero in the
count-down mode or reaches 9 in the count-up mode. The
TC output will then remain HIGH until a state change
occurs, whether by counting or presetting or until U/D is
changed. The TC output should not be used as a clock sig-
nal because it is subject to decoding spikes. The TC signal
is also used internally to enable the Ripple Clock (RC) out-
put. The RC output is normally HIGH. When CE is LOW
and TC is HIGH, the RC output will go LOW when the clock
next goes LOW and will stay LOW until the clock goes
HIGH again. This feature simplifies the design of multi-
0
–P
Pin Names
3
CE
CP
P
PL
U/D
Q
RC
TC
) is loaded into the counter and appears on
0
0
–P
–Q
3
3
Count Enable Input (Active LOW)
Clock Pulse Input (Active Rising Edge)
Parallel Data Inputs
Asynchronous Parallel Load Input (Active LOW)
Up/Down Count Control Input
Flip-Flop Outputs
Ripple Clock Output (Active LOW)
Terminal Count Output (Active HIGH)
Description
2
stage counters. For a discussion and illustrations of the
various methods of implementing multistage counters,
please see the 74F191 data sheet.
RC Truth Table
Mode Select Table
*TC is generated internally
H
L

X
LOW Voltage Level
PL
HIGH Voltage Level
Immaterial
H
H
H
L
LOW-to-HIGH Clock Transition
LOW Pulse
CE
H
X
L
CE
X
H
L
L
Inputs
HIGH/LOW
Inputs
50/33.3
50/33.3
50/33.3
1.0/3.0
1.0/1.0
1.0/1.0
1.0/1.0
1.0/1.0
TC*
H
X
L
U/D
U.L.
H
X
X
L
CP


X
X
Output I
20 A/ 1.8 mA
20 A/ 0.6 mA
20 A/ 0.6 mA
20 A/ 0.6 mA
20 A/ 0.6 mA
CP
Input I
1 mA/20 mA
1 mA/20 mA
1 mA/20 mA
X
X
Count Up
Count Down
Preset (Asyn.)
No Change (Hold)
IH
OH
/I
/I
IL
OL
Mode
Output
RC
H
H