SN55ALS161, SN75ALS161

OCTAL GENERAL-PURPOSE INTERFACE BUS TRANSCEIVERS

SLLS019E – JUNE 1986 – REVISED NOVEMBER 1999

2

POST OFFICE BOX 655303

description (continued)

The driver outputs general-purpose interface bus (GPIB I/O ports) feature active bus-terminating resistor

sink-current loads up to 48 mA. Each receiver features pnp transistor inputs for high input impedance and

hysteresis of 400 mV on the commercial part, 250 mV on the military part, minimum, for increased noise

immunity. All receivers have 3-state outputs to present a high impedance to the terminal when disabled.

The SN55ALS161 is characterized for operation over the full military temperature range of –55

°C to 125°C. The

SN75ALS161 is characterized for operation from 0

°C to 70°C.

FUNCTION TABLE

RECEIVE/TRANSMIT

CONTROLS

BUS-MANAGEMENT CHANNELS

DATA-TRANSFER CHANNELS

DC

TE

ATN†

ATN†

SRQ

REN

IFC

EOI

DAV

NDAC

NRFD

(CONTROLLED BY DC)

(CONTROLLED BY TE)

H

H

H

R

T

R

R

T

T

R

R

H

H

L

R

T

R

R

R

T

R

R

L

L

H

T

R

T

T

R

R

T

T

L

L

L

T

R

T

T

T

R

T

T

H

L

X

R

T

R

R

R

R

T

T

L

H

X

T

R

T

T

T

T

R

R

H = high level, L = low level, R = receive, T = transmit, X = irrelevant

Direction of data transmission is from the terminal side to the bus side, and the direction of data receiving

is from the bus side to the terminal side.

Data transfer is noninverting in both directions.

† ATN is a normal transceiver channel that functions additionally as an internal direction control or talk

enable for EOI whenever the DC and TE inputs are in the same state. When DC and TE are in opposite

states, the ATN channel functions as an independent transceiver only.