Datasheet

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APPLICATION INFORMATION
V
CC1
V
CC1
V
CC2
SYSTEM-1 SYSTEM-2
V
CC1
1
2
3
4
8
7
6
5
V
CC2
V
CC2
V
CC1
V
CC1
V
CC2
SYSTEM-1 SYSTEM-2
1
2
3
4
8
7
6
5
DIR CTRL
I/O-1
V
CC2
I/O-2
SN74AVCH2T45
DUAL-BIT DUAL-SUPPLY BUS TRANSCEIVER
WITH CONFIGURABLE VOLTAGE TRANSLATION AND 3-STATE OUTPUTS
SCES582F – JULY 2004 – REVISED NOVEMBER 2007
Figure 12 is an example of the SN74AVCH2T45 circuit used in a unidirectional logic level-shifting application.
Figure 12. Bidirectional Logic Level-Shifting Application
PIN NAME FUNCTION DESCRIPTION
1 V
CCA
V
CC1
SYSTEM-1 supply voltage (1.2 V to 3.6 V)
2 A1 OUT1 Output level depends on V
CC1
voltage.
3 A2 OUT2 Output level depends on V
CC1
voltage.
4 GND GND Device GND
5 DIR DIR GND (low level) determines B-port to A-port direction.
6 B2 IN2 Input threshold value depends on V
CC2
voltage.
7 B1 IN1 Input threshold value depends on V
CC2
voltage.
8 V
CCB
V
CC2
SYSTEM-2 supply voltage (1.2 V to 3.6 V)
Figure 13 shows the SN74AVCH2T45 used in a bidirectional logic level-shifting application. Since the
SN74AVCH2T45 does not have an output-enable (OE) pin, system designers should take precautions to avoid
bus contention between SYSTEM-1 and SYSTEM-2 when changing directions.
Figure 13. Bidirectional Logic Level-Shifting Application
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