HIT HD74BC373A Datasheet

HD74BC373A

Octal D Type Transparent Latches With 3 State Outputs

ADE-205-009A(Z)

Rev. 1

March 1993

Description

The HD74BC373A provides high drivability and operation equal to or better than high speed bipolar
standard logic IC by using Bi-CMOS process. The device features low power dissipation that is about 1/5
of high speed bipolar logic IC, when the frequency is 10 MHz. The device has eight D type latches with
three state outputs in a 20 pin package. When the latch enable input is high, the Q outputs will follow the
D inputs. When the latch enable goes low, data at the D inputs will be retained at the outputs until latch
enable returns high again. When a high logic level is applied to the output control input, all outputs go to a
high impedance state, regardless of what signals are present at the other inputs and the state of the storage
elements.

Features

• Input/Output are at high impedance state when power supply is off.

• Built in input pull up circuit can make input pins be open, when not used.

• TTL level input

• Wide operating temperature range input pins

Ta = –40 to + 85°C

Function Table

Inputs
G LE D Output Q

HX X Z
LH L L
LH H H
L L X No change

H : High level
L : Low level
X : Immaterial
Z : High impedance

HD74BC373A

Pin Arrangement

G

1Q
1D
2D
2Q
3Q
3D
4D
4Q

GND

10

1
2
3
4
5

6
7

8

9

20
19
18
17
16
15
14
13
12
11

V
8Q
8D
7D

7Q
6Q

6D
5D
5Q
LE

CC

(Top view)

Absolute Maximum Ratings

Item Symbol Rating Unit

Supply voltage V
Input diode current I
Input voltage V
Output voltage V
Off state output voltage V

CC

IK

IN

OUT

OUT(off)

Storage temperature Tstg –65 to +150 °C
Note: 1. The absolute maximum ratings are values which must not individually be exceeded, and

furthermore, no two of which may be realized at the same time.

–0.5 to +7.0 V
±30 mA
–0.5 to +7.5 V
–0.5 to +7.5 V
–0.5 to +5.5 V

2

HD74BC373A

Recommended Operating Conditions

Item Symbol Min Typ Max Unit

Supply voltage V
Input voltage V
Output voltage V

CC

IN

OUT

Operating temperature Topr –40 — 85 °C
Input rise/fall time*

1

tr, t

f

Note: 1. This item guarantees maximum limit when one input switches.

Waveform: Refer to test circuit of switching characteristics.

Logic Diagram

G

4.5 5.0 5.5 V
0—VCCV
0—VCCV

0 — 8 ns/V

1D

2D

7D

8D

LE

D Q

D Q

D Q

D Q

1Q

2Q

7Q

8Q

3