ashugtiwari
Full Member level 4
Hello,
I have a battery charge balancing circuit which has issue with MOSFET always getting burnt when I connect both the batteries.
As from figure, if G1>G2, PWM1 is on with 12.5% duty cycle, during this time the current from G1 and input current goes through U$10 to charge G2 for balancing charge for both batteries.
if G2>G1, PWM2 on with 12.5% duty cycle during which, current through G1 and from G2 will pass through U$11 to balance charge.
if G1==G2, mosfets are off and batteries will charge as usual.
L7 is used to limit current spike and CT is used to find current value.
The PWM is running at 250kHz.
Now, in any of above conditions, even if both mosfets are off; as soon as i connect both batteries, the mosfets get hot and burnt within few seconds. If only one mosfet is present in circuit, the circuit works fine with charge balancing.PWM's are driven through mosfet driver.
What can be the issue?
I have a battery charge balancing circuit which has issue with MOSFET always getting burnt when I connect both the batteries.
As from figure, if G1>G2, PWM1 is on with 12.5% duty cycle, during this time the current from G1 and input current goes through U$10 to charge G2 for balancing charge for both batteries.
if G2>G1, PWM2 on with 12.5% duty cycle during which, current through G1 and from G2 will pass through U$11 to balance charge.
if G1==G2, mosfets are off and batteries will charge as usual.
L7 is used to limit current spike and CT is used to find current value.
The PWM is running at 250kHz.
Now, in any of above conditions, even if both mosfets are off; as soon as i connect both batteries, the mosfets get hot and burnt within few seconds. If only one mosfet is present in circuit, the circuit works fine with charge balancing.PWM's are driven through mosfet driver.
What can be the issue?