2025-05-20 10:36 AM
I have a been looking at the STBC08 to charge a very small Li Ion battery (Seiko MS-920) which accepts a very small charging current. Is it possible to increase the size of Rprog resistor to accommodate a charge current of ~1mA? From what I read, the maximum value of Rprog is around 12kOhm. Is the primary concern of increasing the value of this resistor feedback loop stability?
Thanks!
2025-05-21 6:26 AM
The data sheet of the STBC08 does not mention an upper limit for Rprog, but a charging current of 1mA would require an Iprog of 1µA and thus an Rprog of 1Mohms (see data sheet, section 6.5 and 6.6). I'm afraid that the leakage currents, for example, are already in the order of magnitude, so I suspect that you can use a maximum of approx. 100kohms for Rprog, which corresponds to 10mA charging current. But you are welcome to test whether 1Mohm also works and gives the required results.
Regards
/Peter