Re: ESR meter to measure internal gate resistance of mosfet/igbt to mOhm accuracy

I think one realistic way to measure it is to assume the gate is a capacitor and apply a small current pulse to it and measure the voltage drop. And do this during the off-state of the transistor.

As long as the voltage drop stays below the threshold voltage there shouldnt be a problem. I could even use a negative current to stop this happening. The issue is that the gate capacitances are maybe 50nF maximum, which means the current is going to need to be in the mA or less range and for...

Re: ESR meter to measure internal gate resistance of mosfet/igbt to mOhm accuracy

Yes I want to see how it evolves over temperature, load current, swithcing frequency etc. Essentially I do not care about the accuracy of the measurement within reason, I care about the repeatability and the resolution of the measurement. I want the highest resolution possible, but I dont mind if I measure say 4.0567ohms if the 'real' value is 1.0546 - as long as my measurement is very repeatable. This is the number 1 criteria. In this way I will be able to look at the changes over operating conditions....

Hi

I am looking to try to measure the internal gate resistance of a power transistor WHILE it is operating in a power converter.

Is it possible with an ESR meter? I know this is done for datasheets (sometimes) using an LCR meter, this can be seen by jedec standards or just through the annotations for frequency and Vac, but the transistor is out of circuit obviously. eg


However I want to try to measure this in circuit, while it is in operation, and to miliohm precision. Let's say the MOSFET/igbt is in a 5kHz single phase inverter, so the measurement...

Re: New Members - please post your introductions here

Hi

I'm here to try to design a system capable of measuring the internal gate resistance of power transistors while they are operating in a power converter.