March 19, 2014, Seoul – Infineon Technologies (Korea CEO Seung-soo Lee) has launched the TLI4970, a high-precision current sensor that requires only about one-sixth of the board space of existing sensors on the market.

The TLI4970 can measure AC and DC up to +/-50A. This fully digital sensor requires no external calibration and features stray magnetic field suppression technology, making it highly robust against external magnetic fields. The sensor can continue measurements with absolute precision and maintain efficiency even after years of continuous operation, while maintaining the control quality level of the application. Additionally, it offers extra features such as rapid overcurrent detection at pre-configurable levels. The TLI4970 is ideal for controlling electric drives and energy-saving LED lighting devices, as well as for use in solar inverters, charging and power supply units. Samples of the TLI4970 are already available, and series mass production is scheduled to begin in May 2014.

The measurement principle of the TLI4970 is based on Infineon's proven Hall effect technology. Since this technology involves detecting the magnetic field of a current-carrying conductor using an essential Hall probe, the TLI4970 does not require a conventional field concentrator. As a result, hysteresis effects, which cause inaccurate measurements, do not occur.

The differential measurement principle implemented in the TLI4970 suppresses interference caused by external magnetic fields. As a result, the sensor achieves a very low offset of only 25mA. In the case of conventional current measurement principles, measurement accuracy is always affected by ambient conditions such as temperature. Furthermore, in practice, non-deterministic drift and aging phenomena negatively impact the accuracy of current measurements, requiring preventive measures in system design. The TLI4970 integrates separate structures for measuring temperature and mechanical stress, eliminating dependence on such external conditions. Since the sensor measures both variables individually during operation, it is possible to ensure continuous and efficient compensation. This forms the basis for long-term measurement stability and reliable, cost-optimized inverters and motors with high efficiency.

In addition to high-precision current measurement, the sensor provides high-efficiency protection at the power output stage. For example, in the case of an external short circuit, dangerous overcurrents can occur. To maintain extremely short delay times, the TLI4970 provides a parallel signal path. This enables error conditions detected by the sensor to be processed directly at the driver stage or microcontroller with an extremely short delay of less than 3µs. System developers can finely tune overcurrent thresholds to meet application requirements by programming both the sensor's current value and filtering.

The SMD package integrates a current bar, making it possible to bring the sensor to a perfectly calibrated state. As a result, customers do not need to perform the time-consuming subsequent calibration process during assembly.

The TLI4970 is one of the first current sensors to transmit measured values via an SPI interface. The sensor is equipped with a differential amplifier, filter, and signal processing functions, and can perform galvanic isolation measurements with an operating voltage of up to 600V and a test voltage of up to 3,600V.

The TLI4970 is available in an ultra-small TISON (Thin Interstitial Small Outline No leads) SMD package measuring just 7x7x1mm. Cost-effective automated component placement is possible with TISON SMD packages.