Texas Instruments has introduced what it claims as the industry’s first zero-drift Hall-effect current sensors. The TMCS1100 and TMCS1101 enable the lowest drift and highest accuracy over time and temperature while providing reliable 3-kVrms isolation, which is especially important for AC or DC high-voltage systems such as industrial motor drives, solar inverters, energy-storage equipment and power supplies.
Ongoing demand for higher performance in industrial systems is driving the need for more precise current measurement, in addition to reliable operation, which often comes with the cost of increased board space or design complexity, says TI. The company has applied its expertise in both isolation and high-precision analog to the TMCS1100 and TMCS1101, enabling engineers to design systems that will provide consistent performance and diagnostics over a longer device lifetime, keeping its solution size compact without increasing design time.
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 aging. With an industry-leading total sensitivity drift over temperature of 0.45%, maximum, which is at least 200% lower than other magnetic current sensors, and a maximum full-scale offset drift of <0.1%, the devices provide the highest measurement accuracy and reliability across a wide range of current. Further, a 0.5% lifetime sensitivity drift, which is at least 100% lower than other magnetic current sensors, significantly reduces the performance degradation associated with system aging over time.
Additionally, the ultra-high accuracy of the TMCS1100 (1%, maximum) and TMCS1101 (1.5%, maximum) eliminates the need for device calibration, which reduces equipment maintenance over time. The devices also provide typical linearity of 0.05%, which minimizes signal distortion and helps maintain accuracy across the extended industrial temperature range (-40°C to 125°C).
The high-quality construction of the TMCS1100 and TMCS1101 provides inherent galvanic isolation capable of delivering 3-kVrms of 60-second isolation per the Underwriters Laboratories (UL) 1577 standard for demanding environmental conditions in grid-connected or power systems. Both devices support a ±600-V lifetime working voltage—up to 40% higher than competitive devices in the same 8-pin SOIC package and have been rigorously tested beyond industry-standard UL and VDE requirements for greater design margin and an extended device lifetime.
The TMCS1100 requires an external voltage reference for differential measurement, enabling engineers to optimize their design to meet the most stringent performance goals. The TMCS1101, however, integrates the voltage reference, providing high performance in a pin-to-pin industry-standard implementation to simplify designs while reducing total cost.
The TMCS1100 and TMCS1101 are now available from TI and authorized distributors in an 8-pin small-outline integrated circuit (SOIC) package. Pricing for both sensors starts at US$1.50 in 1,000-unit quantities. Full and custom quantity reels are available on TI.com and through other channels. The TMCS1100EVM and TMCS1101EVM evaluation modules (EVMs) are available for purchase on TI.com for US$59.00 each.
Texas Instruments | www.ti.com