TPS56C215: Power-up sequence regarding VREG5 to MODE

Daisuke Higa

Part Number: TPS56C215

Hi support team.

I received some questions from my customer about power-up sequence for TPS56C215.

1. Whitch correct the delay time of VREG5 to MODE is 100us or 200us?

2. If 200us is correct, why did the read start delay time from VREG5 to MODE change when changing the datasheet from Rev.C to D?
The delay time in the datasheet Rev.C was 100us.

Best regards,

Higa

over 4 years ago

0 Lishuang Zhao over 4 years ago

TI__Expert 7500 points

Hi Higa,

I just found there is a mismatch. I will double check which is correct and feedback to you soon.

Thanks,

Lishuang

0 Lishuang Zhao over 4 years ago in reply to Lishuang Zhao

TI__Expert 7500 points

Hi Higa,

Firstly, the delay time 200us should be correct. The description in sentence should be missed to correct.

From Rev.C to Rev.D, figure 7-2 was not only changed the delay time from 100us to 200us, but also changed the fourth signal from Vout to SS which was matched with internal design delay. Figure 7-2 power up sequence is not the right waveform on bench. Mode signal in Figure 7-2 can only show the internal MODE reference voltage to check MODE pin divider ratio.

Overall, after VREG5 crosses its UVLO, the delay time to SS ramping up should be about 300us.

Thanks,

Lishuang

0 Daisuke Higa over 4 years ago in reply to Lishuang Zhao

Genius 4340 points

Hi Zhao-san

Thank you for your reply.

I understand.

Why did you change the delay time of VREG5-MODE to 200us?
Did you change the circuit inside the device?
Or was it 200us from the beginning?

This is a question from my customer.

Best regards,

Higa

0 Lishuang Zhao over 4 years ago in reply to Daisuke Higa

TI__Expert 7500 points

Hi Higa,

No, we didn't change the circuit inside. The beginning delay should be have some mismatch/misunderstanding with the internal design so that we decided to change.

Please convince customer that there is no change within device.

Thanks,

Lishuang

0 Daisuke Higa over 4 years ago in reply to Lishuang Zhao

Genius 4340 points

Thank you for your prompt reply.

I understand.

Regards,

Higa

Power management

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TPS56C215: Power-up sequence regarding VREG5 to MODE