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Electronics => Beginners => Topic started by: 404notfound on February 17, 2025, 12:38:12 pm

Title: Help with TPS61023
Post by: 404notfound on February 17, 2025, 12:38:12 pm

Hi all,

I am having some issues with a TPS61023 from Texas Instrument.

I am using WEBENCH Power Designer from TI to design my power supply. (Link  https://webench.ti.com/appinfo/webench/scripts/SDP.cgi?ID=596F065B4F17B3A1  (https://webench.ti.com/appinfo/webench/scripts/SDP.cgi?ID=596F065B4F17B3A1) to "my" design).

In theory, I can work from ~1.5V to 3.6V to boost voltage up to 3.3V.

However, below 2.5V, the IC "shuts off"...

I checked the feedback pin, it ranged from 0.3V bellow 2.5V input to 0.4;0.6V with input voltage above 3V.

This "power supply" powered an ESP 12F. You can check my PCB design here: https://pro.easyeda.com/editor#id=a962e7a75ae043559788beba2e07cb2e

Is there an obvious problem?
Thanks !

Title: Re: Help with TPS61023
Post by: xvr on February 18, 2025, 11:29:52 am

Output capacitor placed too far from IC. Datasheet says:

Quote

The most critical current path for all boost converters is from the switching FET, through the rectifier FET, then
the output capacitors, and back to ground of the switching FET. This high current path contains nanosecond rise
and fall time and must be kept as short as possible. Therefore, the output capacitor not only must be close to the
VOUT pin, but also to the GND pin to reduce the overshoot at the SW pin and VOUT pin.

Also input bulk capacitor recomended:

Quote

The device is designed to operate from an input voltage supply range between 0.5 V to 5.5 V. This input supply
must be well regulated. If the input supply is located more than a few inches from the converter, additional bulk
capacitance may be required in addition to the ceramic bypass capacitors. A typical choice is a tantalum or
aluminum electrolytic capacitor with a value of 100 μF.

Title: Re: Help with TPS61023
Post by: CaptDon on February 18, 2025, 01:27:53 pm

Operates from .5v to 5.5v and the input must be well regulated???? That seems like a stupid spec for a buck / boost converter. If by well regulated they mean lots of bulk capacitance it should state that parameter, which I think they do. The operating input voltage varies over a decade, I wouldn't call that 'well regulated'.