Do you need any thermal compensation for the drivers in an output stage with Lateral FETs?
Since the Laterals are thermally stable with just a resistor or resistor+pot in the vbe multiplier, thermal compensation for the BJT drivers should not be needed.
From what I can see from other designs with Lat FET output stages and BJT drivers, no thermal compensation seems to be needed.
Since the Laterals are thermally stable with just a resistor or resistor+pot in the vbe multiplier, thermal compensation for the BJT drivers should not be needed.
From what I can see from other designs with Lat FET output stages and BJT drivers, no thermal compensation seems to be needed.
the original Hitachi data sheets & app notes (as well as old Hafler construction manuals) recommended 100mA per device quiescent current puts you pretty close to the zero tempco point for the lateral MOSFETs. If you do the same, you likely woon't need any fancy tempco circuitry.
My 2 cents,
I would not place the drivers on the main heatsink, this to avoid big temperature changes for the drivers.
I you place the drivers on a smaller heatsink and set the OPS bias after that the driver heatsinks reached a stable temperature, it should be fine. That's my experience.
Greetz
I would not place the drivers on the main heatsink, this to avoid big temperature changes for the drivers.
I you place the drivers on a smaller heatsink and set the OPS bias after that the driver heatsinks reached a stable temperature, it should be fine. That's my experience.
Greetz
Was talking about the BJT drivers needing thermal compensation, not the Lateral FETs.
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