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74F779 Datasheet, PDF (2/12 Pages) NXP Semiconductors – 8-bit bidirectional binary counter 3-State
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Philips Semiconductors
8-bit bidirectional binary counter (3-State)
Product specification
74F779
FEATURES
• Multiplexed 3-State I/O ports for bus oriented applications
• Built-in look-ahead carry capability
• Center power pins to reduce effects of package inductance
• Count frequency 145MHz typical
• Supply current 90mA typical
• See 74F269 for 24-pin separate I/O port version
• See 74F579 for 20-pin version
• See 74F1779 for extended function version of the 74F799
DESCRIPTION
The 74F779 is a fully synchronous 8-stage Up/Down Counter with
multiplexed 3-State I/O ports for bus-oriented applications. All
control functions (hold, count up, count down, synchronous load) are
controlled by two mode pine (S0, S1). The device also features
carry look-ahead for easy cascading. All state changes are initiated
by the rising edge of the clock. When CET is High the data outputs
are held in their current state and TC is held High. The TC output is
not recommended for use as a clock or asynchronous reset due to
the possibility of decoding spikes.
PIN CONFIGURATION
I/O1 1
I/O2 2
I/O3 3
GND 4
I/O4 5
I/O5 6
I/O6 7
I/O7 8
16 I/O0
15 CP
14 CET
13 VCC
12 TC
11 S0
10 S1
9 OE
SF01259
TYPE
74F779
TYPICAL fMAX
145MHz
TYPICAL
SUPPLY CURRENT
(TOTAL)
90mA
ORDERING INFORMATION
DESCRIPTION
COMMERCIAL RANGE
VCC = 5V ±10%,
Tamb = 0°C to +70°C
16-Pin Plastic DIP
N74F779N
16-Pin Plastic SOL
N74F779D
PKG DWG #
SOT38-4
SOT 162-1
INPUT AND OUTPUT LOADING AND FAN-OUT TABLE
PINS
DESCRIPTION
Data inputs
I/On
Data outputs
S0, S1
Select inputs
OE
Output Enable input (active Low)
CET
Count Enable Trickle input (active Low)
CP
Clock input (active rising edge)
TC
Terminal Count output (active Low)
NOTE:
One (1.0) FAST Unit Load is defined as: 20µA in the High state and 0.6mA in the Low state.
74F(U.L.)
HIGH/LOW
3.5/1.0
150/40
1.0/1.0
1.0/1.0
1.0/1.0
1.0/1.0
50/33
LOAD VALUE
HIGH/LOW
70µA/0.6mA
3.0mA/24mA
20µA/0.6mA
20µA/0.6mA
20µA/0.6mA
20µA/0.6mA
1.0mA/20mA
1989 Sep 20
2
853–0385 97676
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