www.ti.com

DESCRIPTION/ORDERING INFORMATION (CONTINUED)

SN74ALVCH16973

8-BIT BUS TRANSCEIVER AND TRANSPARENT D-TYPE LATCH

WITH FOUR INDEPENDENT BUFFERS

SCES435B – APRIL 2003 – REVISED SEPTEMBER 2004

When the latch-enable (LE) input is high, the Q outputs follow the data (A) inputs. When LE is taken low, the Q

outputs are latched at the levels set up at the A inputs. The latch output-enable (LOE) input can be used to place

the nine Q outputs in either a normal logic state (high or low logic level) or the high-impedance state. In the

high-impedance state, the Q outputs neither drive nor load the bus lines significantly. LOE does not affect

internal operations of the latch. Old data can be retained or new data can be entered while the Q outputs are in

the high-impedance state.

through pullup resistors; the minimum values of the resistors are determined by the current-sinking capability of

the drivers.

The four independent noninverting buffers perform the Boolean function Y = D and are independent of the state

of DIR, TOE, LE, and LOE.

The A and B I/Os and D inputs have bus-hold circuitry. Active bus-hold circuitry holds unused or undriven data

inputs at a valid logic state. Use of pullup or pulldown resistors with the bus-hold circuitry is not recommended.

FUNCTION TABLES

INPUTS

OPERATION

TOE

DIR

L

L

B data to A bus

L

H

A data to B bus

A bus and B bus

H

X

isolation

INPUTS

OUTPUT

Q

LOE

LE

A

L

H

H

H

L

H

L

L

L

L

X

H

X

X

Z

INPUT

OUTPUT

D

Y

L

L

H

H

2