| 摘要 |
PROBLEM TO BE SOLVED: To prevent breakdown when supplying power to an amplifier requiring positive and negative power supplies as a drive power supply such as MMIC. SOLUTION: When power is turned on, a positive power supply circuit 1 is turned on, a negative power supply circuit 2 starts operating at a first reference voltage or higher, and a negative voltage rises to a nearly constant voltage at a second reference voltage. A negative voltage detection circuit 4 detects the negative voltage until this point and outputs a negative voltage detection signal. Also, the negative voltage is directly applied to a negative voltage supply terminal 7b of an MMIC 7. When the positive voltage further rises to a third reference voltage, a positive voltage detection circuit 5 operates and outputs a positive voltage detection signal. A judgment circuit 6 turns on a switch circuit 3 when both negative and positive voltages are inputted and applies a positive voltage to a positive voltage supply terminal 7a of the IC 7, thus preventing the positive voltage from being applied before supplying the negative voltage. When a power supply is interrupted, the positive voltage is turned off before the negative voltage stops. |
