Infineon Technologies AG has announced precision current sensor TLI4970 to measure alternating and direct currents up to +/-50A. The digital sensor which does not require external calibration is not affected by external magnetic fields. While maintaining the precision after years of use, this sensor offers additional functions such as fast overcurrent detection at a pre-configurable level. The TLI4970 is designed for use in solar inverters, charging devices and power supplies as well as for electric drives and for controlling energy-saving LED lighting units. Samples of the TLI4970 are already available. Series production is due to commence in May 2014.
The Hall effect based sensor uses integral Hall probes to detect the magnetic field of a current-carrying conductor. The TLI4970 is not affected by hysteresis effects, which would lead to measuring inaccuracies.
The differential measuring principle helps this sensor to suppress interference caused by external magnetic fields and consume low offset of just 25mA.
The TLI4970 uses separate structures for measuring the temperature and the mechanical stress, so that long-term measurement stability is achieved.
TLI4970 is also fast in sensing current by providing a parallel signal path. This allows the error condition detected by the sensor to be processed with an extremely short delay of less than 3 µs directly in the driver stage or in the microcontroller. To fine-tune the overcurrent threshold to the requirements of the application, the system developer can program both the current value and the subsequent filtering in the sensor, as per Infineon.
Other features explained by Infineon includes:
The integration of the current bar in the SMD package permits complete calibration of the sensor on delivery. This also dispenses with the need for a subsequent, time-consuming calibration process by the customer during assembly.
The TLI4970 is one of the first current sensors to transmit the measured values via the digital SPI interface. It integrates e.g. differential amplifiers, filters and signal processing and permits the implementation of a galvanically isolated measurement up to 600V operating voltage and up to 3,600V test voltage.
SMD package for automatic component placement
The TLI4970 will be offered in an extremely compact TISON (Thin Interstitial Small Outline No leads) SMD package with dimensions of just 7x7x1mm. Thanks to the TISON SMD package, automatic cost-efficient component placement is possible.
Samples of the TLI4970 are available. Series production is scheduled to begin in May 2014.