Zero drift Hall-effect current sensors are an industry first, says Texas Instruments
Engineers can achieve consistent, accurate measurements over time and temperature in high-voltage systems, using the TMCS1100 and TMCS1101 Hall-effect current sensors. They are claimed to be the first zero drift Hall-effect current sensors and to enable the lowest drift and highest accuracy over time and temperature while providing reliable 3kVrms isolation. These characteristics make them particularly suitable for AC or DC high voltage systems such as industrial motor drives, solar inverters, energy-storage equipment and power supplies.
The zero-drift architecture and real-time sensitivity compensation of the TMCS1100 and TMCS1101 enable extremely high performance, even under operational conditions such as temperature changes and equipment ageing. Texas Instruments claims that the total sensitivity drift over temperature of 0.45 per cent, maximum, is at least 200 per cent lower than other magnetic current sensors. Maximum full scale offset drift of up to 0.1 per cent enables the devices to provide the highest measurement accuracy and reliability across a wide range of current, adds the company. A 0.5 per cent lifetime sensitivity drift is at least 100 per cent lower than other magnetic current sensors, says Texas Instruments, which reduces the performance degradation associated with system ageing over time.
The high accuracy of the TMCS1100 (one per cent, maximum) and the TMCS1101 (1.5 per cent, maximum) eliminates the need for device calibration, which reduces equipment maintenance over time. The current sensors also provide typical linearity of 0.05 per cent, which minimises signal distortion and helps maintain accuracy across the extended industrial temperature range (-40 to +125 degrees C).
The construction of the TMCS1100 and TMCS1101 provides inherent galvanic isolation capable of delivering 3kVrms of 60 second isolation per the UL 1577 standard for demanding environmental conditions in grid-connected or power systems.
Both current sensors support a ±600V lifetime working voltage. This is up to 40 per cent higher than competitive devices in the same eight-pin SOIC package, reports Texas Instruments.
The TMCS1100 requires an external voltage reference for differential measurement, and the TMCS1101 integrates the voltage reference, providing a pin-to-pin industry-standard implementation to simplify designs while reducing total cost, Texas Instruments explains.
The TMCS1100EVM and TMCS1101EVM evaluation modules (EVMs) are also available.