(A) multi-node CMOS temperature sensor with the compensation of the reverse early effect error

Abstract

This paper presents a CMOS temperature sensor which provides the multi-node sensing and adopts the proposed compensation method for the reverse Early effect error in a 0.18um CMOS process. The BJT-based temperature sensor suffers from the non-linearity errors in the temperature. The sources of the non-linearity error are described. The reverse Early effect error which is the dominant source of the non-linearity errors is compen-sated by the proposed analog method. The sensor error appears $-0.2 ^\circ C$ to $1.5 ^\circ C$ before the compensation and $-0.08 ^\circ C$ to $0.32 ^\circ C$ after the compensation over the temperature range of $-50 ^\circ C$ to $150 ^circ C$. The compensated sensor output can be applied to the analog application directly with high accuracy. It is also utilizable in the digital application with a usual ADC. Therefore, this temperature sensor is available in both of the analog and the digital application.