TDP0604: Power on sequence query

Jaden Yue

Part Number: TDP0604

Hi Team,

Could you please help explain the function of internal POR, EN and Reset signal for power on timing requirement? I did not find too many information about internal POR in datasheet. It seems like the internal POR is active low. According to the datasheet Reset signal is the logical AND of internal POR and EN pin, also as informed by datasheet TDP0604 will be held in reset when low. Does it mean the TDP0604 during red marked interval at below snap is in reset status?

Best Regards,

Jaden Yue

over 2 years ago

0 David (ASIC) Liu over 2 years ago

TI__Guru**** 161026 points

Jaden

TDP0604 is in reset state when EN pin is high (red marked interval). The important thing to remember is to hold EN pin low until VCC and VIO is up and stable. There is an internal 250k pullup to VIO on EN pin, so all you need is an external pulldown capacitor on EN. The external pulldown and internal pullup will create a RC constant time delay to make sure the EN pin will go from low to high after the VCC/VIO is up and stable. You can change the capacitor value to decrease/increase the delay time.

Thanks

David

0 Jaden Yue over 2 years ago in reply to David (ASIC) Liu

TI__Expert 5825 points

Hi David,

Thanks for your explanation. Still a bit confused about the reset function. If EN pin is high for reset state, do you mean after power on the TDP0604 is always in reset state? So what will happen in reset state?

Best Regards,

Jaden Yue

+1 David (ASIC) Liu over 2 years ago in reply to Jaden Yue

TI__Guru**** 161026 points

Jaden

No, TDP0604 is in reset state when EN is low. TDP0604 is in normal state when EN is high.

As long as you can guarantee that EN goes high after VCC and VIO ramps up and becomes stable, then TDP0604 is OK.

Thanks

David

0 Jaden Yue over 2 years ago in reply to David (ASIC) Liu

TI__Expert 5825 points

Hi David,

Do you recommend EN pin external pulldown or controlled by processor?

Best Regards,

Jaden Yue

0 Brian Zhou over 2 years ago in reply to Jaden Yue

TI__Guru*** 126730 points

prefer controlled by processor.

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TDP0604: Power on sequence query