Current sensors simplify design

Texas Instruments (TI) has unveiled a new portfolio of current sensors, targeting a broad range of common-mode voltages and temperatures. Designed to help engineers simplify their designs and improve accuracy, the new products include a lowest-drift isolated Hall-effect current sensor for high-voltage systems and a line of current shunt monitors that eliminate the need for an external shunt resistor for non-isolated voltage rails.

Targeting high-voltage systems, TI claims the new TMCS1123 Hall-effect current sensor offers the industry’s highest reinforced isolation and highest accuracy over lifetime and temperature. For non-isolated systems up to 85 V and 75 A_RMS, the new EZShunt portfolio touts the industry’s smallest fully integrated current shunt monitor and the industry’s highest-accuracy 75-A integrated shunt solution.

Cost, size, accuracy and speed

The new devices address four key factors – cost, size, accuracy and speed – when selecting a current-sensing solution, said TI. The TMCS1123, for example, offers fast and accurate control in high-voltage systems, while the EZShunt portfolio offers both cost-optimized and high-accuracy options as well as a smaller solution by eliminating the need for an external shunt resistor.

TI said that Hall-effect current sensors have typically been overlooked for high-voltage systems, including for electric-vehicle chargers and solar inverters, due to their high drift over lifetime.

Applications for current sensors (Source: Texas Instruments)

The TMCS1123 Hall-effect current sensor claims the highest reinforced isolation working voltage of 1,100 V_DC. It also features a maximum sensitivity error of ±0.75% with 50 ppm/°C drift over temperature and ±0.5% drift over lifetime, along with a low propagation delay of 600 ns and bandwidth of 250 kHz, which delivers faster control loops and lower noise to help increase efficiency.

“With this high accuracy, the TMCS1123 enables designers to optimize system performance while simplifying design,” said TI. “The high precision and stability over lifetime remove the need to recalibrate equipment, reducing costly and time-consuming maintenance.”

The EZShunt portfolio eliminates the need for a shunt resistor, offering fully integrated current-sensing solutions in a 1206 package. In addition to offering cost-optimized and high-accuracy options, the line offers drift as low as 25 ppm/°C, in a variety of packages and shunt values. As examples, the INA700 is claimed as the industry’s smallest integrated current shunt monitor, enabling a reduction in the size of current-sensing solutions by as much as 84%, while the INA781 touts the industry’s highest-accuracy 75-A integrated shunt solution, which supports common-mode voltages up to 85 V.

Preproduction quantities of the TMCS1123 Hall-effect current sensor are available now, only on TI.com, in a 10.3 × 10.3-mm, 10-pin SOIC package. Pricing starts at $2.37 in quantities of 1,000. The TMCS1123EVM evaluation module is priced at $49.99.

Preproduction quantities of EZShunt products are available now, only on TI.com, in a variety of package options as small as 1.319 × 1.239-mm. Pricing starts at $0.80. Pricing for evaluation modules starts at $49.99.

Higher bandwidth and automotive-qualified versions of the TMCS1123 are expected to be available in the fourth quarter of 2023 and second quarter of 2024, respectively. Analog and automotive versions of EZShunt products are expected to be available in the second quarter of 2024.