TXB0104-Q1: VCCA<VCCB

Chuqiang Wen

Part Number: TXB0104-Q1
Other Parts Discussed in Thread: SN74AXC4T774-Q1,

Hi expert,

Do we have another device which no limited on VCCA≤VCCB? This voltage translator uses for SPI voltage translated from 3.3V(power1) to 3.3V(power2) and in automotive application. These two 3.3V power rail may have little difference. So customer would like to choose some devices which no limited on VCCA and VCCB.

Thanks!

Ethan Wen

over 3 years ago

0 Clemens Ladisch over 3 years ago

Guru 316640 points

Differences up to 0.5 V are harmless.

Anyway, for SPI, a better solution would be the SN74AXC4T774-Q1.

0 Chuqiang Wen over 3 years ago in reply to Clemens Ladisch

TI__Expert 5825 points

Hi Clemens,

Thanks for your quickly reply.

Clemens Ladisch said:
Differences up to 0.5 V are harmless.

You mean if VCCA>VCCB within 0.5V is harmless for TXB0104-Q1? Do we have some test data can share regarding this?

Clemens Ladisch said:
Anyway, for SPI, a better solution would be the SN74AXC4T774-Q1.

For SN74AXC4T774-Q1, I don't see any limited on VCCA and VCCB. Is it correct? I discussed with customer for this device, Bidirectional device would be better.

BTW, why are you saying SN74AXC4T774-Q1 is a better solution?

Thanks!

Ethan Wen

0 Clemens Ladisch over 3 years ago in reply to Chuqiang Wen

Guru 316640 points

See Biasing Requirements for TXS, TXB, and LSF Auto-Bidirectional Translators.

To allow auto-bidirectionality, the TXB has very strict requirements on the input signal drive strength and the output load. The AXC device has proper buffers.

Logic

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TXB0104-Q1: VCCA<VCCB