Patent Number: 6,683,549

Title: Digital-to-analog converter

Abstract: A digital-to-analog converter which can be used with multi-bit digital codes without increasing the module size thereof, as well as a current source and a differential amplifier, which are preferably used in the digital-to-analog converter. A constant current source supplies a current corresponding to the LSB in a digital code to be converted, resistors generate voltages corresponding to bits other than the LSB in the digital code, and as the generated voltages are applied to the gate terminals of MOSFETs, the MOSFETs permit passage of the currents corresponding to the bits other than the LSB in the digital code. A current source, together with the resistors, provides voltages to be applied to the gate terminals of the MOSFETs, which voltages make the MOSFETs operate in a sub-threshold region, and also make the MOSFETs permit passage of the currents corresponding to the bits.

Inventors: Kinugasa; Yukihisa (Tokyo, JP)

Assignee: Oki Electric Industry Co., Ltd.

International Classification: H03M 1/74 (20060101); H03M 001/00 ()

Expiration Date: 01/27/2012