| 摘要 |
PURPOSE:To obtain a driving circuit which has a low power consumption and is made small-sized easily and has a high-speed operation, by providing a means, which flows an excess current only for a short time from the conversion time of switching of a PIN diode from backward to forward, in a constant current circuit. CONSTITUTION:Driving signals which are inputted to terminals 1 and 1' and have phases opposite to each other are amplified in a differential pulse amplifier 17 and are applied to the base of a transistor (TR) 11 through the base of a TR9 and a capacitor C10. The TR9 is operated as a low impedance circuit, and the TR11 is operated as a constant current circuit by applying a proper potential to the base. During the transition time of switching of a PIN diode D13 from forward to backward, the emitter voltage of the TR9 is changed from a positive voltage to a negative voltage in accordance with the change of the base voltage, and the TR9 is cut off, an the TR11 flows a large current for a short time, and the electric charge due to the barrier capacity of the D13 is discharged. Simultaneously, the electric charge in an I layer of the D13 is set to the steady state quickly, and all of the current supplied from the TR11 is flowed to the D13, and a constant forward current is flowed to the D13 in the steady state. |
