A Digitally Calibrated Current-Voltage Feedback Transconductor in 0.13-μm CMOS Process

Abstract

A digitally calibrated transconductor for high-speed operation with its linearity enhanced by negative feedback is proposed. This voltage-to-current converter is mainly composed of two parts: an operational transconductance amplifier (OTA) and a pair of feedback resistors. The measured spurious free dynamic range (SFDR) of the transconductor is 72.6 dB when the input frequency is 100 MHz. To compensate common-mode deviation due to process variation, digital calibration circuits are added. Fabricated in TSMC 0.13-μm CMOS process, the transconductor occupies 250 × 200 μm2 active area and consumes 5.06 mW from a 1.2-V supply.