Digital control attenuator

Abstract

Abstract PURPOSE:To control an analog signal in equal digital step with a simple constitution, by supplying an input signal to the input of the 1st stage through cascade connection of a plurality of signal attenuators, controlling it with a digital control signal and obtaining an output signal from the final stage. CONSTITUTION:Input ternimals 4-1-4-4 of a digital control signal in 4-bit binary have weight of 2<0>, 2<1>, 2<2>, 23. Buffer amplifiers 5-1-5-4 are provided corresponding to each bit of the digital control signal to drive corresponding switches SWP1- SWP4. Inverters 6-1-6-4 drive switches SWS1-SWS4 which invert the outputs of each amplifier, and when the voltage at terminals 4-N (where: N=1-4) is ''0'', the switch SWSN is turned on and the switch SWPN is turned off, and when the voltage is ''1'', the switch SWSN is turned off and the switch SWSN turns on. Thus, the amplitude of analog input signal can be outputted into equal digital step control with a simple constitution.

Inventors

• 👤 Masaru Uya

Bibliographic Details