Hello,
I am planning on using the BQ24450 to charge two 12V 3.4Ah SLA batteries. When trying to calculate the component values Im having difficulty with the following equation:
Vboost = Vref × (RA + RB + RC//RD) ÷ RC//RD → RD = 474.3kΩ.
Using numbers from the example and substituting (Ra+Rb=92.8kohm = 92800ohm, and x = Rd):
2.45V=2.3V*(92800+((46400*x))/(x+46400))/((46400*x)/(x+46400))
plugging this formula into wolfram alpha to solve for x we get:
x = Rd = -47964
note that the answer in the datasheet is 474.3kohm
The answer I got would be close but it seems that the decimal place is off, if converter from 47964 to kilo-ohms it would be 47.964kohm which is 10 times less than the data sheet value.
Any help in determining what I did wrong would be great help! Thank you :)