Datasheet
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DESCRIPTION/ORDERING INFORMATION (CONTINUED)
GQL OR ZQL PACKAGE
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J
H
G
F
E
D
C
B
A
21 3 4 65
K
SN74LVCH16T245
16-BIT DUAL-SUPPLY BUS TRANSCEIVER
WITH CONFIGURABLE VOLTAGE TRANSLATION AND 3-STATE OUTPUTS
SCES635A – JULY 2005 – REVISED AUGUST 2005
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.
This device is fully specified for partial-power-down applications using I
off
. The I
off
circuitry disables the outputs,
preventing damaging current backflow through the device when it is powered down.
The V
CC
isolation feature ensures that if either V
CC
input is at GND, then all outputs are in the high-impedance
state. The bus-hold circuitry on the powered-up side always stays active.
To ensure the high-impedance state during power up or power down, OE should be tied to V
CC
through a pullup
resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
TERMINAL ASSIGNMENTS
(1)
1 2 3 4 5 6
A 1DIR NC NC NC NC 1 OE
B 1B2 1B1 GND GND 1A1 1A2
C 1B4 1B3 V
CCB
V
CCA
1A3 1A4
D 1B6 1B5 GND GND 1A5 1A6
E 1B8 1B7 1A7 1A8
F 2B1 2B2 2A2 2A1
G 2B3 2B4 GND GND 2A4 2A3
H 2B5 2B6 V
CCB
V
CCA
2A6 2A5
J 2B7 2B8 GND GND 2A8 2A7
K 2DIR NC NC NC NC 2 OE
(1) NC – No internal connection
FUNCTION TABLE
(1)
(EACH 16-BIT SECTION)
CONTROL INPUTS OUTPUT CIRCUITS
OPERATION
OE DIR A PORT B PORT
L L Enabled Hi-Z B data to A bus
L H Hi-Z Enabled A data to B bus
H X Hi-Z Hi-Z Isolation
(1) Input circuits of the data I/Os are always active.
2