Digital/analog converter

Abstract

Abstract PURPOSE:To attain analog digital conversion with high conversion accuracy by constituting the titled converter by an analog switch circuit whose on- resistance forms a ladder type resistance circuit, an analog switch circuit changing the connection of the ladder type resistance circuit in response to a digital code signal input value, a reference voltage source and an operational amplifier. CONSTITUTION:The titled device consists of an analog switch circuit S1 whose onresistance forms a ladder type resistance circuit, an analog switch circuit S to change the connection of the ladder type resistance circuit in response to the digital code signal input, the reference voltage source Vref supplying a voltage to the ladder type resistance circuit and an operational amplifier OP receiving the output voltage of the ladder type resistance circuit. Then the on-resistance of the analog switch circuits S,S1 is used as resistors R, 2R in the ladder type resistance circuit. Thus, it is not required to select the on- resistance to be a small value and the highly accurate ladder type resistance circuit is obtained by the combination of the on-resistance and the other resistors.

Inventors

• 👤 Yutaka Awata
• 👤 Kinji Kawada

Bibliographic Details