TPS65400-Q1: TPS65400 Design questions

user5913722

Part Number: TPS65400-Q1
Other Parts Discussed in Thread: TPS65400

1>. if no I2C control, default only one PGOOD output? so can't use PGOOD to control power up sequence

2>. when VIN=12V, VO=1V, what is the highest Fsw? when i set one of outputs to 0.9V, webench set the fsw as 1MHZ, but your TON min is 150ns.

3>. how to calculate the compensation parts? any documents?

4>. if no I2C controller, need sequence control, any special attention?

0 Sam(MPAA) Zhang over 6 years ago

Hi,

1. Yes, by default there is only one PG pin available.

2. Please follow the information on datasheet. Highest Fsw can be calculated by Ton_min/Duty

3. You can take any of materials talking about the loop compensation of current mode DCC converter. Or just use Webench to get the reference results.

4. You may use resistor divided previous channel Vout to enable the following channel.

Thanks!

Regards,

Hao

0 user5913722 over 6 years ago in reply to Sam(MPAA) Zhang

thanks for your reply，another question here.

when i set one of outputs at 1.0V, webench tell me, can't create design and its min output is 0.8V.

I plan to set 500kHZ, VIN=12V, Vo=1V/0.6A, caculate from min Ton=150ns, TPS65400 shall support 1v Vo.

Can u confirm whether it support 1v output? webench setting as followings.

0 Sam(MPAA) Zhang over 6 years ago in reply to user5913722

Hi,

I've tried on Webench by myself. Seems 12V to 1V at 500kHz operating condition is good to generate a design.

Any way, please just follow the information on datasheet. (1/12)*(2us)=166ns > 150ns. So there should be no problem here.

Thanks!

Regards,

Hao

Power management forum