A ± 36A integrated current-sensing system with 0.3% gain error and 400µA offset from −55°C to +85°C

Abstract

This paper presents an integrated shunt-based current-sensing system (CSS) capable of handling ±36A currents, the highest ever reported. It also achieves 0.3% gain error and 400μA offset, which is significantly better than the state-of-the-art. The heart of the system is a robust 260μΩ shunt made from the lead-frame of a standard HVQFN plastic package. The resulting voltage drop is then digitized by a ΔΣ ADC and a bandgap reference (BGR). At the expense of current handling capability, a ±5A version of the CSS uses a 10mΩ on-chip metal shunt to achieve just 4μA offset. Both designs were realized in a standard 0.13μm CMOS process.