Temperature-Compensated $\beta$ -Multiplier Current Reference Circuit

Abstract

This brief presents the new simple schematic for the temperature stable current references based on the well-known $\boldsymbol {\beta }$ -multiplier circuit. The proposed reference utilizes only four MOS transistors and two lateral PNP transistors, which are usually available in standard CMOS technologies along with one well resistor. The temperature-compensation technique has a low process dependence and needs no trimming. However, resistor trimming can be used to precisely set the output current value. The circuit implementation of the proposed technique was fabricated in a standard 0.35- ${\mu }\text{m}$ CMOS process to source a 16- ${\mu }\text{A}$ current. The digital calibration circuit allows setting of the output current in 32 100 nA-steps. The proposed current reference achieves the supply sensitivity of several %/V without the use of the external bandgap voltage reference for the supply regulation. The measured temperature coefficient is 105 ppm/°C over the temperature range from 0 to 110 °C.