Patent attributes
A constant current source apparatus is provided that includes a complementary switching section that selectively outputs a reference voltage or a driving voltage according to a control signal and a constant current source circuit that causes a constant current determined by the reference voltage to flow to a load in a case where the reference voltage is received from the complementary switching section and cuts off the current flowing to the load in a case where the driving voltage is received from the complementary switching section. The complementary switching section includes a first FET in which one of either a source or a drain is connected to the driving voltage, the other source or drain is connected to an output end of the complementary switching section, and a gate receives the voltage according to the control signal and a second FET that switches to an opposite polarity of the first FET in which one of either a source or a drain is connected to the reference voltage, the other source or drain is connected to the output end of the complementary switching section, and a gate receives the voltage according to the control signal.