TPS92691: Separate power, boost MOSFET gate driver

Roman Simonyan

Intellectual 440 points

Part Number: TPS92691

Hi. I have 2 questions.

We plan to use TPS92691 in boost topology. Vin 20-50V, Vout 54-58V. Iout 5A.

To minimize loses:

1. Can I use separate 12V for Vin and 48V for boost converter.

2. Can I use a MOSFET gate driver?

If anything will not work, please explain why.

Thank you,
Roman

over 6 years ago

0 Tuan Tran74 over 6 years ago

TI__Mastermind 18890 points

Hi Roman,

1. Yes, you can use a 12V input if it's readily available into the TPS92691 to minimize loses on the internal VCC linear regulator.
2. The TPS 92691 has an internal gate drive designed to drive external FET's already so please look at it's drive capability. There is leading edge blanking on the TPS92691 (103nS - 188nS) to do current sensing on IS so if you use an external gate driver you will need to consider the external gate driver delay time.

Thanks Tuan

0 Roman Simonyan over 6 years ago in reply to Tuan Tran74

Intellectual 440 points

Thanks, Tuan.

I plan using a driver which has 15ns delay. So, it should be ok, right?

Roman

0 Tuan Tran74 over 6 years ago in reply to Roman Simonyan

TI__Mastermind 18890 points

Hi Roman,

That should be fine. What frequency are you plan to switching at? Why do you feel you need an external FET driver? Is our internal FET drive not strong enough for your external FET?

Thansk Tuan

0 Roman Simonyan over 6 years ago in reply to Tuan Tran74

Intellectual 440 points

We plan using 400kHz. Qgtot will be 60-80nC.

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TPS92691: Separate power, boost MOSFET gate driver