A3938

A3938 Three-Phase Power MOSFET Controller FEATURES AND BENEFITS ▪ Drives a wide range of N-channel MOSFETs ▪ Low-side synchronous rectification ▪ Power MOSFET protection ▪ Adjustable dead time for cross-conduction protection ▪ Selectable coast or dynamic brake on power-down or RESET input ▪ Fast/slow current decay modes ▪ Internal PWM current control ▪ Motor lead short-to-ground protection ▪ Internal 5 V regulator ▪ Fault diagnostic output ▪ Thermal shutdown ▪ Undervoltage protection Package 38-pin TSSOP (suffix LD): Not to scale DESCRIPTION The A3938 is a three-phase, brushless DC motor controller. It has a high-current gate drive capability that allows driving of a wide range of power MOSFETs and can support motor supply voltages to 50 V. The A3938 integrates a bootstrapped high-side driver to minimize the external component count required to drive N-channel MOSFET drivers. Internal fixed off-time, PWM current-control circuitry can be used to regulate the maximum load current to a desired value. The peak load current limit is set by the user’s selection of an input reference voltage and external sensing resistor. A userselected external RC timing network sets the fixed off-time pulse duration. For added flexibility, the PWM input can provide speed/torque control where the internal current control circuit sets a limit on the maximum current. The A3938 includes a synchronous rectification feature. This shorts out the current path through the power MOSFET reverse body diodes...