SN74LVCH16T245: Level Shifter

Esther Lee

Part Number: SN74LVCH16T245
Other Parts Discussed in Thread: ADS131E08, , TXU0304, SN74LVC16T245

Hi,

I would like to check if SN74LVCH16T245 is suitable for SPI communication between ADS131E08 and a 5V controller. Would it be possible to point me to some application notes or suggested schematics for this?

over 3 years ago

0 Clemens Ladisch over 3 years ago

Guru 316440 points

Why did you choose a sixteen-channel device? SPI has four signals, so I'd recommend something like the TXU0304.

0 Esther Lee over 3 years ago in reply to Clemens Ladisch

Prodigy 70 points

There are other digital pins(START etc) which makes a total of 14 so I was intending to convert those as well.

0 Clemens Ladisch over 3 years ago in reply to Esther Lee

Guru 316440 points

The SN74LVCH16T245 can be used, if you can fit your signals in the two eight-channel groups in each direction.

This device has bus-hold inputs; if you need pull-up/-down resistors, you should use the SN74LVC16T245 instead.

See the typical application in section 10.2 of the datasheet.

0 Esther Lee over 3 years ago in reply to Clemens Ladisch

Prodigy 70 points

Thanks for the recommendation. Just to confirm, if I have 1 set of output signals and 1 set of input signals:

1. To translate output signals from 3.3V to 5V, I can place them on 1B1-1B8 (3.3V) and set 1OE and 1DIR to low which would translate them to 1A1-1A8 (5V) respectively.

2. To translate input signals from 5V to 3.3V, I can place them on 2A1-2A8 (5V) and set 2OE to low and 2DIR to high which would translate them to 2B1-2B8 (3.3V) respectively.

3. If I don't want conversion from either end, I can set the respective OE to high.

0 Clemens Ladisch over 3 years ago in reply to Esther Lee

Guru 316440 points

Correct.

Please note that setting /OE high disables only the outputs, but not the inputs, so you still have to ensure that all I/O pins have a valid voltage (near GND or V_CC).

0 Esther Lee over 3 years ago in reply to Clemens Ladisch

Prodigy 70 points

Ok, thanks!

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SN74LVCH16T245: Level Shifter