TPS61201: TPS61201 can't output 3.3V when input>0.3V.

lee Peng

Part Number: TPS61201

My project is harvesting the radio frequency energy and store it in a capacitor. After the capacitor is a TPS61201. According to the datasheet, the input range is 0.3-5V, when I using a 1.5V 3A battery to test the booster, the output is 0.25V only!! Here is my circuit.

over 6 years ago

0 Minqiu Xie over 6 years ago

TI__Mastermind 21565 points

Hi Peng：
Does issue happen with no load?

Please share the part number of the inductance better with its datasheet.

0 lee Peng over 6 years ago in reply to Minqiu Xie

Intellectual 720 points

No load. The inductor is 0805 chip inductor which has not datasheet.

0 Minqiu Xie over 6 years ago in reply to lee Peng

TI__Mastermind 21565 points

Hi Peng:
Please change the inductance with similar parameter recommenced in Table 3 of the datasheet.
If it doesn't work, please catch the waveform of the Vin, Vout, SW, and share you layout. Thank you.

0 lee Peng over 6 years ago in reply to Minqiu Xie

Intellectual 720 points

you mean I must use the LPS3015-222ML from Coilcraft? Actually, I am using a 0805 chip iductor(2.2uh), the symbol in the picture is not right.

0 Minqiu Xie over 6 years ago in reply to lee Peng

TI__Mastermind 21565 points

No, not just Coilcraft.
I just recommend to use similar parameter inductance with 2.2uH, Isat>1.2A.

0 lee Peng over 6 years ago in reply to Minqiu Xie

Intellectual 720 points

I had renewed the schematic . And if the booster works well, will the output change as the load change? Can this booster output 3.3v at 0.3v input or 0.5v input at least?

0 Minqiu Xie over 6 years ago in reply to lee Peng

TI__Mastermind 21565 points

Hi Peng:
I think it's another question.

1. And if the booster works well, will the output change as the load change?
In normal work mode, the output will be regulate at target value.

2. Can this booster output 3.3v at 0.3v input or 0.5v input at least?
Yes, it could. But it may support small load.

0 lee Peng over 6 years ago in reply to Minqiu Xie

Intellectual 720 points

Ok. Thx. I will try to change the inductor. Please keep this forum open, I will feedback after the test.

0 Minqiu Xie over 6 years ago in reply to lee Peng

TI__Mastermind 21565 points

Hi Peng:
You're welcome. If you have any supplement, just post below.

0 lee Peng over 6 years ago in reply to Minqiu Xie

Intellectual 720 points

I had found an inductor(Isat=1A) from Wurth Elektronik, also found somewhere of the booster IC poorly contact. In these picture, CH1=VOUT,CH2=VOUT.

C17 is the storage capacitor. Please ignore R1 and R2. The value of other components are the same as the example in the datasheet.

After welding again, the Vout reaches 3.3V but it is very noisy as the first figure shows. Now the booster can work so that I start to test.

Firstly, I charge a 470uf capacitor to 2V, and then connect it to the booster but the Vout is even lower than 2V. Is that because the capacitor discharge too quickly?

And I wonder, what is the practical minimum input voltage which can get 3.3v output? I had used a power supplier to test, the voltage didn't reach 3.3V until the input = around 1.2V!

Many thanks

0 Minqiu Xie over 6 years ago in reply to lee Peng

TI__Mastermind 21565 points

Hi Peng:
Please show the schematic for me. Especially the partnumber of the Cin/Cout.
What what's the load during the test?

0 Minqiu Xie over 6 years ago in reply to Minqiu Xie

TI__Mastermind 21565 points

Hi Peng:
Long time not hear from you. I assume you have solved the issue. If not, just reply below~ Thank you.

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TPS61201: TPS61201 can't output 3.3V when input>0.3V.