| 摘要 |
PURPOSE:To perform the A/D conversion with a required resolution over a wide range of level by obtaining the result of A/D conversion from an attenuation of a variable attenuator or a sum of fluctuations in a gain variable amplifier. CONSTITUTION:A high-frequency signal is inputted from an input terminal 1, amplified by an amplifier 2, an output signal of variable attenuators 101-10N is detected by a detector 3 and a detecting voltage is obtained. This detecting voltage is compared with a reference voltage 11 by a voltage comparator 5, and until the said detecting voltage is coincident with the reference voltage, a controller 6 and a register 7 change over the attenuation of the variable attenuators 101-10N. When the said detecting voltage is coincident with the reference voltage, the output of the voltage comparator 5 stops the operation of the controller 6 and the register 7, and the A/D conversion is finished. N sets of the variable attenuators 101-10N can be replaced with N sets of gain variable amplifiers. |
