UT54ACS373 Datasheet, PDF (1/10 Pages) Aeroflex Circuit Technology – Octal Transparent Latches with Three-State Outputs

Standard Products
UT54ACS373/UT54ACTS373
Octal Transparent Latches with Three-State Outputs
Datasheet
November 2010
www.aeroflex.com/logic
FEATURES
‰ 8 latches in a single package
‰ Three-state bus-driving true outputs
‰ Full parallel access for loading
‰ 1.2μ CMOS
- Latchup immune
‰ High speed
‰ Low power consumption
‰ Single 5 volt supply
‰ Available QML Q or V processes
‰ Flexible package
- 20-pin DIP
- 20-lead flatpack
‰ UT54ACS373 - SMD 5962-96588
‰ UT54ACTS373 - SMD 5962-96589
DESCRIPTION
The UT54ACS373 and the UT54ACTS373 are 8-bit latches
with three-state outputs designed for driving highly capacitive
or relatively low-impedance loads. The device is suitable for
buffer registers, I/O ports, and bidirectional bus drivers.
The eight latches are transparent D latches. While the enable
(C) is high the Q outputs will follow the data (D) inputs. When
the enable is taken low, the Q outputs will be latched at the levels
that were set up at the D inputs.
An output-control input (OC) places the eight outputs in either
a normal logic state (high or low logic levels) or a high-imped-
ance state. The high-impedance third state and increased drive
provide the capability to drive the bus line in a bus-organized
system without need for interface or pull-up components.
The output control OC does not affect the internal operations of
the latches. Old data can be retained or new data can be entered
while the outputs are off.
The devices are characterized over full military temperature
range of -55°C to +125°C.
FUNCTION TABLE
INPUTS
OUTPUT
OC
C
nD
nQ
L
H
H
H
L
H
L
L
L
L
X
nQ₀
H
X
X
Z¹
Note:
1. Data may be latched internally.
PINOUTS
20-Pin DIP
Top View
OC 1
20
V_DD
1Q 2 19 8Q
1D 3 18 8D
2D 4 17 7D
2Q 5 16 7Q
3Q 6
3D 7
15 6Q
14 6D
4D 8 13 5D
4Q 9 12 5Q
V_SS 10 11 C
20-Lead Flatpack
Top View
OC
1 20
V_DD
1Q
2 19
8Q
1D
3 18
8D
2D
4 17
7D
2Q
5 16
7Q
3Q
6 15
6Q
3D
7 14
6D
4D
8 13
5D
4Q
9 12
5Q
V_SS
10 11
C
LOGIC SYMBOL
(1)
OC
EN
(11)
C
C1
1D ⁽³⁾
1D
2D ⁽⁴⁾
3D ⁽⁷⁾
4D ⁽⁸⁾
5D ⁽¹³⁾
6D ⁽¹⁴⁾
7D ⁽¹⁷⁾
8D ⁽¹⁸⁾
(2)
(5)
1Q
2Q
(6) _3Q
(9) _4Q
(12) _5Q
(15) _6Q
(16) _7Q
(19) _8Q
Note:
1. Logic symbol in accordance with ANSI/IEEE Std 91-1984 and IEC
Publication 617-12.
1