Biasing circuit suitable for differential current steering DAC (Digital-to-Analog Converter)

The invention discloses a bias circuit suitable for a differential current steering DAC (Digital-to-Analog Converter), which belongs to the field of integrated circuit design and comprises a clamping voltage generation module and a gate end bias voltage generation module. The clamping voltage generation module generates clamping voltage through an operational transconductance amplifier OTA and a current mirror network, serves as input of a transimpedance amplifier and is used for clamping voltage at the output end of a differential DAC switch current source array, it is guaranteed that when different digital signals are input, the voltage at the drain end of a current mirror tube of the current source array is kept unchanged, and the voltage at the output end of the differential DAC switch current source array is kept unchanged. The matching performance of the DAC current source array and the reference current source is improved; and the gate end bias voltage generation module generates the gate end bias volt