Hello, Whats the difference if we have current sources that drives the gates of mosfet versus voltage sources ?? Thanks in advance, Su
MOSFET: current sources versus voltage sources that drives the gates of mosfet
Jul 16, 2009
2 Replies
Never heard of this before. Why do you want to drive a MOSFET with a current source?
A MOSFET requires a voltage across its gate and source to switch it on (VGS). Looking into the gate, it looks like a capacitance. There will be an inrush current to charge the capacitance, but this will decay to zero once the capacitor is charged.
If you switch on a FET with a current source, the voltage across the current source will rise up to try to maintain the current into the gate and probably over-voltage the Vgs spec.
Use a voltage source instead. Much easier
Bill
www.electronworks.co.uk
Electronic Kits for Education and Fun
Could it be the poster is referring to bipolar technology to drive the gates?
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