TPS65131-Q1: control OUTPUT delay time

Hello Lawrence,

 You can modify the capacitor however it is part of the regulation loop and will affect these.

I have seen application with CP = 22 nF that worked fine however a three times larger capacitance can and will operate differently.

You will need to check the load transient on both rails and check if it will works stable under all operating conditions.

• What is your maximum output current?
• What delay time (VNEG-PG to VPOS-PG) do you need?

Thank you.

Best Regards.

Ilona

Hi, Ilona

 PVOS output current as below chart.

1. maximum output current 820mA/ 6.45V 

2. VNEG-PG to VPOS-PG need delay time 3.2ms.

Thank you,

Best regards,

Lawrence.

Hello Lawrence,

Could you please explain why you want to change the CP cap to achieve a later startup of VPOS? Why not just delaying ENP compared to ENN without touching the regulation loop?

Best regards,
Brigitte

Hi, Brigitte

our client change CP cap want delay output time 3.2ms, becausse want to control output current shunt and we fine tune ENP compared to ENN .
and we fine tune add RC compont but output delay time was not working.

If any question , Please advise me.

Thanks,

Best regards,

Lawrence.

Hello Lawrence,

Could you prove your statements with a scope plot? Please measure the start-up behavior including the output voltage VPOS and VNEG and the ENP and ENN pin.

Thank you.
Best Regards.
Ilona

Hello Lawrence,

Is this issue still topical or have you managed to solve it? Please give us a short note.

Thank you.
Best Regards.
Ilona

Hi, Ilona

Our client changing CP cap from 10nF to 68nF  and test load transient on both rails and check if it will works stable under all operating conditions.

Thanks,

Best regards,

Lawrence.