TPS61089: Reducing the high frequency noise by slowing down the turn-on of the MOSFET in an integrated boost converter

Nick Alexeev

Part Number: TPS61089

Folks,

I'm figuring out how to design a boost converter with low levels of noise. I've read this TI app note about reducing EMI from TPS61088 .

I've also read this Microchip app note (AN1466), which suggests to slow down the turn-on of the integrated MOSFET. This is a fairly common technique, and it's usually implemented by adding a small resistance in series with a MOSFET gate. This is easy to do if one has a controller with an external MOSFET. But what to do with converter ICs which have an integrated MOSFET? The microchip app note suggests to add a resistor in front of the power supply pin which powers the gate driver.

my question: Would a resistor in series with the BOOT pin on the TPS61089 be a viable way of reducing EMI?
The value of the resistor I have in mind is between 10Ω and 100Ω .

Any suggestion, insight or reference is really appreciated!

Cheers,
- Nick

over 5 years ago

0 Helen chen over 5 years ago

TI__Mastermind 40080 points

Dear Sir,

To deduce the EMI suggest you refer to the app note: TI app note about reducing EMI from TPS61088

Unlike the buck converter, add resistor in series with the boot cap doesn't helpful. Because the SW ring is determined by the low side FET. while the boot capacitor is for the high side FET.

The EMI of the TPS61089 is quite good, there's no customer complain about its EMI performance.

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TPS61089: Reducing the high frequency noise by slowing down the turn-on of the MOSFET in an integrated boost converter