I have designed a boost converter based around the TPS61200 chip. This is a low voltage boost converter with a varying input of around 1.5V and 400mA.
The output of the circuit is 3.3V. However, when I connect a load (3.3V fan that draws 60mA) the voltage drops to 1.5V output. When I connected a motor (3V that draws 18mA) the voltage dropped to 50mV output!
I've also purchased an off the shelf module which experiences the same issue, so it's probably not my circuit design.
The components I'm using on the board are the following:
- Boost IC - TPS61200 (https://www.ti.com/lit/ds/symlink/tps61200.pdf?ts=1598365314165&ref_url=https%253A%252F%252Fwww.ti.com%252Fstore%252Fti%252Fen%252Fp%252Fproduct%252F%253Fp%253DTPS61200DRCR)
- 1MOhm resistor - RCC04021M00FKED (https://www.vishay.com/docs/20066/rcce3.pdf)
- 180kOhm resistor - RTT03184JTP (https://datasheet.lcsc.com/szlcsc/1811081933_RALEC-RTT03184JTP_C103362.pdf)
- 2.2uH inductor - CKCS5040-2.2uH/M-2131 (https://datasheet.lcsc.com/szlcsc/1912111437_CENKER-CKCS5040-2-2uH-M-2131_C354604.pdf)
- 10uF capacitor - RDEC71H106K3K1H03B (https://www.mouser.co.uk/datasheet/2/281/RDE_X7R_X7S_25V-100V_E-1671041.pdf)
- 1uF capacitor - RDER72A105K2M1H03A (https://www.mouser.co.uk/datasheet/2/281/c49e-506.pdf)
The off-the-shelf board is from SparkFun: https://www.sparkfun.com/products/10255 I shorted the UVLO as I didn't need it, and set it to 3.3V. I've also tried it on 5V and had the same issue.
Thanks all for your help in advance. Cheers!