Eliminate Large External Current-Sensing Resistors With Compact 600-V IC

March 25, 2014

Measuring high current (10 to 100 A) through a power MOSFET or IGBT typically requires a large resistor, which generates excess power losses (10 to approximately 30 W).

Staff

Measuring high current (10 to 100 A) through a power MOSFET or IGBT typically requires a large resistor, which generates excess power losses (10 to approximately 30 W). International Rectifier’s IR25750 general-purpose current-sensing IC extracts the voltage across a power MOSFET’s internal R_DS(ON)or an IGBT’s V_CE(ON)during the switch’s on-time, eliminating large external current-sensing resistors, heatsinks, and excess power losses. And it does so in a compact SOT23-5L package, significantly reducing space. The IC’s gate-drive input provide the VCC supply voltage and synchronizes the R_DS(ON)and V_CE(ON)sensing circuit to the on and off times of the MOSFET or IGBT. By employing the company’s high-voltage technology, the device features 600-V blocking capability needed to block high V_DS or V_CE voltage during the switch’s off-time. Other features include low gate input capacitance, internal filter delay at turn-on (200 ns typical), and internal 20.8-V Zener clamps on the GATE and CS pins. All inputs and outputs have electrostatic-discharge and latch immunity for rugged monolithic protection.

INTERNATIONAL RECTIFIER