| 摘要 |
PURPOSE:To obtain a programmable variable attenuator which is small in size and responds at a high speed, by storing the variable resistance characteristics of a variable resistance element in a control circuit which controls the variable resistance element. CONSTITUTION:A control section 16 is composed of a storage section 13, DA converter 14, and reference voltage source 13. When external data are inputted in external data input terminals 12a-12n, parameters corresponding to the external data are outputted from the storage section 13. The DA converter 14 converts the parameters into analog information, namely, analog information corresponding to the control current-resistance value characteritics of a variable resistance element 6 and outputs the analog information. As a result, a desired control current is outputted from a control terminal 16a. Therefore, the attenuation quantity of the variable resistance element 6 can optionally be set at a high response. Therefore, a programmable variable attenuator which is small in size and responds at a high speed can be obtained. |
