DS90UB933-Q1: power up sequence

Jiawei Hu1

Part Number: DS90UB933-Q1

Hi team,

For 933 power up sequence, does the VDDIO & VDD18 rise time must be larger than 1ms? It seems too long.

935 and 953 doesn't need such long time.

Jiawei

0 Casey McCrea over 2 years ago

Jiawei,

Is your question about 933 or 934? The screenshot of the power sequence is from the 934 datasheet

Best Regards,

Casey

0 Jiawei Hu1 over 2 years ago in reply to Casey McCrea

Hi Casey,

Sorry for the misunderstanding, it's the question about 934. Thanks!

Jiawei

0 Casey McCrea over 2 years ago in reply to Jiawei Hu1

Jiawei,

The spec is that the rise time of the rails should be greater than 1ms. This is to prevent the ESD cell in the pins from triggering

Best Regards,

Casey

0 Jiawei Hu1 over 2 years ago in reply to Casey McCrea

Casey,

Thanks for your reply, could you kindly tell me how to achieve 1ms? Typically VDDIO and VDD18 are got from LDO, it's hard to achieve.

Jiawei

0 Casey McCrea over 2 years ago in reply to Jiawei Hu1

Hello Jiawei,

Also within TI we have LDOs with integrated soft start for example: TPS74701-Q1

Best Regards,

Casey

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