Other Parts Discussed in Thread: TIDA-00449,
Hi
I'm using the reference circuit from TIDA-00449 and have a few questions I hope can be easily answered. Please refer to the attached image I've created which shows the balancing circuit for a single cell.
What I understand is
a) The N channel MOSFET is turned on by the BQ76930 which enables current to flow from Drain to Source as shown in the image. This allows the voltage of the cell to be lowered.
b) The resistor R39 is there to provide a load otherwise when the MOSFET turned on, it would result in a short-circuit (and damaged MOSFET)
c) The 10K resistor (R40) allows voltage to be applied to the MOSFET Gate but restricts current flow through the Gate - this is because MOSFETs are controlled by voltage not current.
What I do not understand and would like some help on is the following
a) What is the purpose of the 5.6V zener diode (D13)?
b) How does the BQ76930 turn on the MOSFET? Is it via VC1 or VC0, since both are connected to the MOSFET Gate?
c) What is the purpose of the 0.22uF cap (C21)?
d) What is the purpose of the 1.0K resistor (R41)?
Thanks for any help on these questions.
Cheers,
Mike