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From my knowledge, BJTs need to be biased to control its linearity and gain, usually with resistors on the base and collector. Suppose I want a FET in saturation acting as a high-side switch.

Do FETs need to be biased? If so, why? (assume n-channel enhancement)

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  • \$\begingroup\$ Switches doesn’t have to be biased, they just have to be driven with appropriate voltage and current. \$\endgroup\$ Feb 16 at 8:36

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Suppose I want a FET in saturation acting as a high-side switch

I'm assuming that "FET" means an enhancement mode MOSFET (commonly used as a high-side switch). I'm also assuming that when you refer to a high-side switch, you are using an appropriate gate-source driver circuit.

Biasing is used to set a quiescent current from drain to source. If you want a MOSFET to act like a switch, you don't want any gate/base signal present when you want the device to be "off" so, no, in your application, MOSFETs don't need to be biased.

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