Comparator and a control circuit for a power MOSFET
AssigneeNEC Corporation
InventorMitsuru Yoshida
Life of this patent
Estimating the term…
Abstract
A control circuit for a power MOSFET includes a voltage divider for dividing an input voltage, a fixed voltage generator for generating a fixed voltage, a comparator having a differential pair including first and second depletion transistors each receiving the divided voltage or the fixed voltage and a current mirror including first and second enhancement transistors connected in series with the first and second depletion transistors, respectively, an inverter for receiving the output from the comparator, and a power MOSFET controlled for the ON/OFF control thereof by the inverter.
Claims8
A comparator comprising:
- a differential pair including a pair of depletion transistors each having a gate for receiving one of an input signal pair;
- and
- a current mirror including a pair of enhancement transistors each connected in series with a corresponding one of said depletion transistors, a drain of one of said enhancement transistors forming an output terminal for outputting a result of comparison between said signal pair by said comparator.
A control circuit comprising:
- a voltage divider for diving an input voltage to output a divided voltage;
- a fixed voltage generator for generating a fixed voltage:
- a differential pair including first and second depletion transistors, said first depletion transistor having a gate for receiving said divided voltage, said second depletion transistor having a gate for receiving said fixed voltage,
- a current mirror including first and second enhancement transistors, said first enhancement transistor being connected in series with said first depletion transistor, said second enhancement transistor being connected in series with said second depletion transistor, a drain of one of said first and second enhancement transistors outputting a result signal indicating a result of comparison between said fixed voltage and said divided voltage;
- and
- a first MOSFET having a gate controlled by said result signal.
Dependencies are inferred from the claim text.