Hi Jeff,
1. Is the mid point of R5 and R7 supposed to connect to pin 13 CELLS/FB? If so, for 12.6V, R5 needs to be 2X R7. Equation is VBAT=2.1V *(1+R5/R7).
- It's just the voltage divider thank you :-). Also forgot to connect it. For 12.45V, I choose 49.3k and 10k with 0.1% tolerance. Shouldn't they both be quite precise and also thinfilm?
2. Does your battery have a thermistor? If not, R8 and R9 need to be sized so that TS see 1/2 of 3.15 volts.
- both are 10k now.
3. Your ISET resistors are close the values for your desired charge and termination currents but slightly below. Choosing resistors closer to the calculated value per design equations 17 and 18 on datasheet page 4.
I_Charge = 100 mV / 0.43 Ohm = 0.233 A
RISET1 = (1000 x 1.0) / ( 0.43 Ohm x 0.233 A) = 9981,01 -> 10 kOhms
RISET2 = (1000 x 1.0) / ( 0.43 Ohm x 0.233 A) = 9981,01 -> 10 kOhms
is there anything wrong with this?
4. I recommend adding a pull up resistor (maybe LED) to STAT if for no other reason than to help debug issues.
very good idea. thanks.
