ESP8266 Community Forum

- Mon Jun 29, 2015 2:06 pm #21998 I ordered some of these because they were mentioned on the forum...
http://www.ebay.com/itm/310788623921?rmvSB=true
"mini DC-DC Converter Step Down buck Power Supply Module for Flight Control Car"

Update: In my application I am using them to step down 6.0 to 3.3v but I am finding that they occasionally reset themselves down to about 1 V output! Have not figured out what's causing it, or if the devices just "don't work right".

The numbers on the chip are
MP23070N
AC805239
MPS810

Which I suppose is this: MP2307 http://www.datasheet4u.com/download_new.php?id=596551.

Oh well, at least they were cheap.

Any ideas welcome...

- Mon Jun 29, 2015 6:22 pm #22012 Hi

Peter Scargill http://tech.scargill.net/ blogged that he had problems with such buck convertors. He put it down to the esp8266 not drawing enough current for the device to work correctly.

- Mon Jun 29, 2015 7:38 pm #22014 Did you bump the table or otherwise move the regulator when the voltage dropped? 1V is pretty close to the chips reference voltage, which makes me wonder, if that flimsy trim pot on the board might have a loose connection.
On my boards, the pot is connected to ground, so if it were disconnected, the regulators reference pin would only be connected to the positive output (via some resistor), which would cause the regulator to adjust for 0.925V output.

- Tue Jun 30, 2015 6:33 am #22051 That step down power supply uses about 15mA - 18mA quiescent current.
I suggest these about $1 for 1 and a better deal if you buy 5.
I've used them without problems in all my ESP8266 and Arduino projects that need to step down the voltage.
If other devices will be powered from the same 6V supply, put a diode in series with the positive IN of the module and a 470 uF cap across the INPUT of the module.
*The quiescent current of the modules I linked is less then 1mA.