This chip provides a straightforward method of connecting 5V devices, such as an Arduino to 3.3V sensors.

The 74LVC245 can convert logic signals in both directions (5V to 3.3V and 3.3V to 5V), but the direction does need to be selected beforehand, by providing a signal to the DIR pin on the chip. This means that in most cases, if you wanted to convert in both directions at the same time, you would need 2 of these chips. Alternatively you may be able to connect a 3.3V output pin directly to a 5V input pin as 3.3V counts as a TTL 'high' signal. However, if you do choose this option you'd need to make sure that the 5V pin would never be used as an output. This forum post has a useful discussion on using a 74LVC245 for level shifting SPI communications.

If you'd like automatic bidirectional level shifting then you might consider the TXB0108 breakout we sell, although that is more expensive.

Features

• Operates From 1.65 V to 3.6 V
• Inputs Accept Voltages to 5.5 V
• Max propagation delay of 6.3 ns at 3.3 V
• Ioff Supports Partial-Power-Down Mode Operation

Useful Links

SN74LVC245A Datasheet