TPS61235P: Boost Converter Not Starting Up : 0.3V output

Akshay Maharaj

Part Number: TPS61235P

Hi Guys,

I trust you are well.

I'm using the TPS61235 as part of an IOT board.I'm powering the converter from a 3.7v 21700 5Ah LiPo battery. The schematic is attached below:

I have done the following checks so far:

(1) Confirmed that the enable pin is high

(2) Vin applied is greater than the minimum Vin specified in the datasheet.

(3) Isolated the output of the regulator from the rest of the circuit to eliminate the possibility of any loading related issues preventing startup.

Do you guys have any suggestions regarding the potential causes of the output voltage being 0.3V.

Kind Regards,

over 2 years ago

0 Nini Zhong over 2 years ago

TI__Genius 15215 points

I'm a little confused what is the D13 used for? Maybe you can CHECK THE vIN PIN, WHEN GRASP THE WAVEFORM OF inductor current or SW waveforms firstly.

0 Akshay Maharaj over 2 years ago in reply to Nini Zhong

Prodigy 20 points

Hi,

Thanks for the prompt response.

D13 is used as an "ORing" diode to allow switchover to happen when the main power source is removed. However, at this point it is of no consequence as I have removed it(Point 3,above).I have attached the waveforms present on the Vin pin and SW pins on on power on:

(1) Vin

(2) SW

0 Nini Zhong over 2 years ago in reply to Akshay Maharaj

TI__Genius 15215 points

Can you try to start up under open load? then compare with the diode series?

I doubt it's because the output current too large of the characteristic of diode that lead to the phenomenon.

0 Akshay Maharaj over 2 years ago in reply to Nini Zhong

Prodigy 20 points

I have already done this.The result is the same.

0 Nini Zhong over 2 years ago in reply to Akshay Maharaj

TI__Genius 15215 points

The sw is the same with Vin, so there is no charge into the inductor. Make sure the inductor is not short. make sure the esd diode of all the pins to gnd still works.

0 Nini Zhong over 2 years ago in reply to Nini Zhong

TI__Genius 15215 points

You can contact me by e-mail:nini-zhong@ti.com if you still need help.

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TPS61235P: Boost Converter Not Starting Up : 0.3V output