I'm not monitoring temps, so I have a 10k resistor on the THERM pin as=20
recommended.
Rprog is 2K ... battery is 500mAH, and for now I'm charging at 1C.

So the batteries on specify the nominal 3.7V... not much else.  I've=20
found similar-sized units on aliexpress but also with not much other=20
data available.

I'm using the MSOP version, which has no exposed thermal pad.

Cheers,
-Neil.




On 11/27/2018 5:58 AM, RussellMc wrote:
> On Tue, 27 Nov 2018 at 19:29, Neil <picdude3@narwani.org> wrote:
>
>> I'm using an MCP73833-AMI for charging a 1-cell Lipo in a project. This
>> specific charger is looking for a charge voltage of 4.2V, but the
>> voltage never gets to over about 4.09V to 4.13V (tested over several
>> batteries).
>>
>>
> Datasheet:  http://ww1.microchip.com/downloads/en/DeviceDoc/22005b.pdf
>
> uChip evaluation kit manual:
> http://ww1.microchip.com/downloads/en/DeviceDoc/51626a.pdf
>
> uChip Reference Design:
> http://ww1.microchip.com/downloads/en/DeviceDoc/51746a.pdf
>
> What thermistor (or what else) is on THERM pin?  [data sheet / spec]
> (Lack of thermistor MAY alter voltage substantially).
>
> What value of Rprog?
> What charge current.
> What cell used (datasheet/type/...?)
>
> What package?
> Is exposed thermal pad connected to Vss?
>
> ____________________
>
> Related
>
> uChip Portable Power Conversion Design Guide
>
>         http://ww1.microchip.com/downloads/en/DeviceDoc/30009610F.pdf
>
> Cousin - 73831/2
>
>              http://ww1.microchip.com/downloads/en/DeviceDoc/20001984g.pd=
f
>
>
>
>
>        Russell

--=20
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