Current sense amplifier delivers precision in 100V switching systems
High-precision current measurement in noisy power systems becomes easier with the TSC240 from STMicroelectronics, a bidirectional current sense amplifier combining a wide common-mode handling, low offset, and rejection of pulse-width modulation noise.
Accurate shunt measurement becomes difficult when fast switching edges, wide bus voltages, and small shunt drops coexist. The TSC240 addresses this challenge with a zero-drift architecture for high-side and low-side bidirectional sensing, and enhanced rejection of pulse-width modulation transients.
The TSC240 can sense current via a shunt resistor across a wide common-mode voltage range from -4V to 100V while operating from a separate 2.7V to 5.5V supply. A preset gain of 20V/V simplifies the design. This makes the TSC240 suitable for current measurement, over-current protection, monitoring, and feedback loops in motor drives, power stages, telecom equipment, and automotive electronics.
Precision is the key feature. The TSC240 offers excellent 132dB dc common-mode rejection (CMRR), a maximum gain error of 0.2%, a maximum gain drift of 2.5ppm/°C, and a maximum input offset voltage of ±20µV, in addition to maximum offset drift of 150nV/°C. This level of accuracy enables the use of lower-value shunt resistors, which reduces power loss while maintaining measurement accuracy.
Dynamic behavior also suits fast-switching environments. The current sense amplifier offers up to 560kHz bandwidth. Controlled recovery from 12V, 48V, and 100V common-mode steps supports stable sensing in switching converters and motor-control systems.