Datasheet

APPLICATION INFORMATION
1
2
3
6
5
4
V
CC1
V
CC1
V
CC2
V
CC2
SYSTEM-1 SYSTEM-2
1
2
3
6
5
4
V
CC1
V
CC1
V
CC2
SYSTEM-1 SYSTEM-2
DIR CTRL
I/O-1
V
CC2
I/O-2
Pullup/Down
or Bus Hold
(1)
Pullup/Down
or Bus Hold
(1)
SN74LVC1T45
www.ti.com ..................................................................................................................................................... SCES515I – DECEMBER 2003 – REVISED MAY 2009
Figure 2 shows an example of the SN74LVC1T45 being used in a unidirectional logic level-shifting application.
PIN NAME FUNCTION DESCRIPTION
1 V
CCA
V
CC1
SYSTEM-1 supply voltage (1.65 V to 5.5 V)
2 GND GND Device GND
3 A OUT Output level depends on V
CC1
voltage.
4 B IN Input threshold value depends on V
CC2
voltage.
5 DIR DIR GND (low level) determines B-port to A-port direction.
6 V
CCB
V
CC2
SYSTEM-2 supply voltage (1.65 V to 5.5 V)
Figure 2. Unidirectional Logic Level-Shifting Application
Figure 3 shows the SN74LVC1T45 being used in a bidirectional logic level-shifting application. Since the
SN74LVC1T45 does not have an output-enable (OE) pin, the system designer should take precautions to avoid
bus contention between SYSTEM-1 and SYSTEM-2 when changing directions.
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