APPLICATION INFORMATION

1

2

3

6

5

4

SYSTEM-1

SYSTEM-2

1

2

3

6

5

4

SYSTEM-1

SYSTEM-2

DIR CTRL

I/O-1

I/O-2

Pullup/Down

Pullup/Down

SN74LVC1T45

Figure 2 shows an example of the SN74LVC1T45 being used in a unidirectional logic level-shifting application.

PIN

NAME

FUNCTION

DESCRIPTION

1

SYSTEM-1 supply voltage (1.65 V to 5.5 V)

2

GND

GND

Device GND

3

A

OUT

4

B

IN

5

DIR

DIR

GND (low level) determines B-port to A-port direction.

6

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.

Copyright © 2003–2009, Texas Instruments Incorporated

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Product Folder Link(s): SN74LVC1T45