Hi guys.
I'm currently working on a project that switches a 140A semi-inductive load using a 13.2v lithium battery.
I was planning on using a 5v arduino to switch the mosfets with pwm.
My problem is connecting the gate to the positive terminal of the battery(13.2v) switches the circuit, disconnecting it turns it off. But connecting it to a 5v supply blows 1 mosfet and leaves the circuit on. Why?!
5v is above the gate threshold, it's not above Vgs. My current limiting resistor is still giving each mosfet more than 100nA. It doesn't even last until I disconnect the load so it can't be the diodes' fault.
I have 8 IRFB7437 in parallel on a large heatsink, which is overkill.
Vds: 40v
Id: 190 package limited
Vgs : +-20v
Vgs(th): 3.9v
Igss : 100nA
I also have 2 SR506 schottky diodes for extra kickback protection.
The pulldown resistor is 1kohm and the current limiting resistor is 120ohm.
Thanks
I'm currently working on a project that switches a 140A semi-inductive load using a 13.2v lithium battery.
I was planning on using a 5v arduino to switch the mosfets with pwm.
My problem is connecting the gate to the positive terminal of the battery(13.2v) switches the circuit, disconnecting it turns it off. But connecting it to a 5v supply blows 1 mosfet and leaves the circuit on. Why?!
5v is above the gate threshold, it's not above Vgs. My current limiting resistor is still giving each mosfet more than 100nA. It doesn't even last until I disconnect the load so it can't be the diodes' fault.
I have 8 IRFB7437 in parallel on a large heatsink, which is overkill.
Vds: 40v
Id: 190 package limited
Vgs : +-20v
Vgs(th): 3.9v
Igss : 100nA
I also have 2 SR506 schottky diodes for extra kickback protection.
The pulldown resistor is 1kohm and the current limiting resistor is 120ohm.
Thanks