Hi Experts,
Please advise to the query from Cx:
I am currently planning to use the BQ24640, which I know is designed for high currents, but is able to charge at lower currents by changing the sense resistor. I am trying to determine what components play a role in reducing the efficiency at low currents, in order to see if optimization of those components would create a more efficient solution. More specifically, I'm trying to quantify how changing the sense resistor and subsequent sense current will affect the overall circuit efficiency. Our current mode of thinking is that the FETs has some function of control over this efficiency but want to get a deeper understanding of how this effects our circuit. Our two main questions are:
[1] What components have control over the system efficiency? Or what is the dominant component that controls efficiency?
[2] Is the supply charging currents a function of the FET characteristics? What role, if any, do the FET characteristics play in the switching currents present in the system?
Thank you.
Regards,
Archie A.