1

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

Note:

1. Data may be latched internally.

PINOUTS

20-Pin DIP

Top View

20-Lead Flatpack

Top View

LOGIC SYMBOL

INPUTS

OUTPUT

OC

C

nD

nQ

L

H

H

H

L

H

L

L

L

L

X

H

X

X

1

2

3

4

5

7

6

20

19

18

17

16

14

15

OC

1Q

1D

2D

2Q

3Q

3D

8Q

8D

7D

7Q

6D

8

13

4D

5D

6Q

9

12

4Q

5Q

10

11

C

1

2

3

4

5

7

6

20

19

18

17

16

14

15

OC

1Q

1D

2D

2Q

3Q

3D

8Q

8D

7D

7Q

6D

813

4D

5D

6Q

912

4Q

5Q

10

11

C

(1)

OC

EN

(3)

1D

(4)

2D

(7)

(2)

1Q

(6)

(5)

2Q

Note:

1. Logic symbol in accordance with ANSI/IEEE Std 91-1984 and IEC

Publication 617-12.

3D

(8)

4D

(13)

5D

(14)

6D

3Q

(15) 6Q

(12)

5Q

(9)

4Q

(17)

7D

(18)

8D

(19) 8Q

(16) 7Q

(11)

C

C1

1D