Power supply circuit and power supply apparatus
A power supply circuit includes: a depression mode transistor that includes a field plate; an enhancement mode transistor to which a source electrode and a drain electrode of the depression mode transistor are coupled; and a constant current source that is coupled to a connection node between the depression mode transistor and the enhancement mode transistor.
1. A power supply circuit, comprising:
a depression mode transistor that includes a field plate;
an enhancement mode transistor to which a drain electrode and a source electrode of the depression mode transistor are coupled; and
a constant current source that is coupled to a connection node between the depression mode transistor and the enhancement mode transistor.
2. The power supply circuit according to claim 1 ,
wherein the depression mode transistor is formed of a compound semiconductor device including nitrogen.
3. The power supply circuit according to claim 1 ,
wherein the field plate is a source field plate coupled to the source electrode of the depression mode transistor.
4. The power supply circuit according to claim 1 ,
wherein the constant current source flows a current of 1×10 −11 to 1×10 −2 of a rated current of the depression mode transistor.
5. A power supply apparatus, comprising:
a DC-DC converter; and
a power supply circuit configured to supply power to the DC-DC converter,
wherein the power supply circuit includes
a depression mode transistor that includes a field plate,
an enhancement mode transistor to which a drain electrode and a source electrode of the depression mode transistor are coupled, and
a constant current source that is coupled to a connection node between the depression mode transistor and the enhancement mode transistor.