Hi there,
I've put together a circuit to drive a P-Channel MOSFET from an Arduino Uno. My first mistake is that I got the PCB upside down and all my surface mount components face the Uno, making troubleshooting difficult. My second mistake I cannot identify, but it involved smoke that wasn't related to a BBQ or fireplace.
I've inserted the circuit below (the section I was testing and smoking).
The top connector, J7, had a 12V sealed lead acid battery connected.
The lower connector, J8, had my benchtop power supply connected.
Line 3 coming in from the left is an Auduino digital pin. I set it low to turn on the FET, high to turn off the FET.
Capacitor C9 on the solar line was not installed, as the capacitors I have are all 16V (no good for a 12V nominal solar panel).
When I increased the voltage on my benchtop power supply to 17V (current limit at 2.2A), a lot of smoke started coming out.
Once I'd isolated all power and confirmed no active flame, it became apparent that the Si8261BAD-C-IS isolated gate driver was the victim (U39 in image). The driver side has the case rupture, the signal side looks ok still (+1 to isolation).
I can't for the life of me work out why the gate driver fried. Datasheet says that VDD can go up to 30V. The FQP7P06 shouldn't take much if any gate current (they don't do they?), so the low output current of the gate driver shouldn't matter surely?
Please don't judge my soldering, I'm way out of practice.
The bottom connector in the photo (2 pins, connector on other side) is teh battery. The top one is the solar input.
The trace from solar going elsewhere is simply a potential divider into the ADC.
The battery trace going elsewhere is simply driving an 8V linear regulator and a potential divider into the ADC. The battery trace also drives another FET outside the image for load control, but I haven't tested this yet.
If anyone can see anything obvious, I'd really appreciate the assistance.
Cheers,
Andrew
I've put together a circuit to drive a P-Channel MOSFET from an Arduino Uno. My first mistake is that I got the PCB upside down and all my surface mount components face the Uno, making troubleshooting difficult. My second mistake I cannot identify, but it involved smoke that wasn't related to a BBQ or fireplace.
I've inserted the circuit below (the section I was testing and smoking).
The top connector, J7, had a 12V sealed lead acid battery connected.
The lower connector, J8, had my benchtop power supply connected.
Line 3 coming in from the left is an Auduino digital pin. I set it low to turn on the FET, high to turn off the FET.
Capacitor C9 on the solar line was not installed, as the capacitors I have are all 16V (no good for a 12V nominal solar panel).
When I increased the voltage on my benchtop power supply to 17V (current limit at 2.2A), a lot of smoke started coming out.
Once I'd isolated all power and confirmed no active flame, it became apparent that the Si8261BAD-C-IS isolated gate driver was the victim (U39 in image). The driver side has the case rupture, the signal side looks ok still (+1 to isolation).
I can't for the life of me work out why the gate driver fried. Datasheet says that VDD can go up to 30V. The FQP7P06 shouldn't take much if any gate current (they don't do they?), so the low output current of the gate driver shouldn't matter surely?
Please don't judge my soldering, I'm way out of practice.
The bottom connector in the photo (2 pins, connector on other side) is teh battery. The top one is the solar input.
The trace from solar going elsewhere is simply a potential divider into the ADC.
The battery trace going elsewhere is simply driving an 8V linear regulator and a potential divider into the ADC. The battery trace also drives another FET outside the image for load control, but I haven't tested this yet.
If anyone can see anything obvious, I'd really appreciate the assistance.
Cheers,
Andrew