Philips Semiconductors

Product specification

74F657

Octal transceiver with 8-bit parity generator/checker

90 July 30

5

FUNCTION TABLE

NUMBER OF INPUTS THAT ARE HIGH

INPUTS

INPUT/OUTPUT

OUTPUTS

OE

T/R

ODD/EVEN

PARITY

ERROR

OUTPUTS MODE

0, 2, 4, 6, 8

L

L

L

L

L

L

H

H

L

L

L

L

H

L

H

H

L

L

H

L

H

L

H

L

Z

Z

H

L

L

H

Transmit

Transmit

Receive

Receive

Receive

Receive

1, 3, 5, 7

L

L

L

L

L

L

H

H

L

L

L

L

H

L

H

H

L

L

L

H

H

L

H

L

Z

Z

L

H

H

L

Transmit

Transmit

Receive

Receive

Receive

Receive

Don’t care

H

X

X

Z

Z

Z

Notes to function table

1. H = High voltage level

2. L

= Low voltage level

3. X = Don’t care

4. Z = High impedance ”’off” state

ABSOLUTE MAXIMUM RATINGS

(Operation beyond the limit set forth in this table may impair the useful life of the device. Unless otherwise noted these limits are over the

operating free air temperature range.)

SYMBOL

PARAMETER

RATING

UNIT

Supply voltage

–0.5 to +7.0

V

Input voltage

–0.5 to +7.0

V

Input current

–30 to +5

mA

Voltage applied to output in high output state

V

Current applied to output in low output state

A0 – A7

48

mA

B0 – B7, PARITY, ERROR

128

mA

Operating free air temperature range

Commercial range

0 to +70

Industrial range

–40 to +85

Storage temperature range

–65 to +150

RECOMMENDED OPERATING CONDITIONS

SYMBOL

PARAMETER

LIMITS

UNIT

MIN

NOM

MAX

Supply voltage

4.5

5.0

5.5

V

High–level input voltage

2.0

V

Low–level input voltage

0.8

V

Input clamp current

–18

mA

High–level output current

A0 – A7

–3

mA

B0 – B7, PARITY, ERROR

–15

mA

Low–level output current

A0 – A7

24

mA

B0 – B7, PARITY, ERROR

64

mA

Operating free air temperature range

Commercial range

0

+70

Industrial range

–40

+85