Littelfuse, Inc.
Overcurrent protection by depletion mode MOSFET and bi-metallic temperature sensing switch

Abstract:

Circuits for providing overcurrent and overvoltage protection are disclosed herein. The circuits feature a depletion mode MOSFET (D MOSFET) as a current limiter, the D MOSFET being connected to a bi-metallic switch, where the bi-metallic switch acts as a temperature sensing circuit breaker. In combination, the D MOSFET and bi-metallic switch are able to limit current to downstream circuit components, thus protecting the components from damage.