May 2020

INDUSTRY NEWS 13 www.power-mag.com Issue 2 2020 Power Electronics Europe SiC MOSFET Driver Achieves AEC-Q100 Automotive Qualification The SIC1182KQ (1200 V) and SIC1181KQ (750 V) SCALE-iDriver devices are optimized for driving SiC MOSFETs in automotive applications, exhibiting rail-to-rail output, fast gate switching speed, unipolar supply voltage supporting positive and negative output voltages, integrated power and voltage management and reinforced isolation. Critical safety features include Drain to Source Voltage (V DS ) monitoring, SENSE readout, primary and secondary Undervoltage Lock-out (UVLO), current-limited gate drive and Advanced Active Clamping (AAC) which facilitates safe operation and soft turn-off under fault conditions. AAC in combination with V DS monitoring ensures safe turn- off in less than 2 µs during short-circuit conditions. Gate-drive control and AAC features allow gate resistance to be minimized. Functional description The gate drivers provide up to 8 A and suit SiC MOSFETs with standard gate-emitter voltages from +15 V, with various negative voltages in the range from -3 V to -15 V. Devices exhibit high external magnetic field immunity, and are available in a compact eSOP package that provides ≥ 9.5 mm of creepage and clearance, using material that has the highest CTI level (CTI =600 per IEC 60112). The logic input (PWM) command signal applied via IN and the primary supply voltage supplied via V CC are both referenced to GND. The working status of the semiconductor device and SCALE- iDriver is monitored via SO. Command signals are transferred from the primary (IN) to secondary- side via FluxLink isolation technology. GH supplies a positive gate voltage and charges the semiconductor gate during the turn-on process. GL supplies a negative gate voltage and discharges the gate during turn-off process. Short-circuit protection as well as over-voltage limitation can be implemented by connecting a network between SNS and drain terminal of the semiconductor device. In case of a turn-on event SNS senses short-circuits, which will lead to a driver initiated turn-off to protect the semiconductor device from short-circuit damage. In case of a turn-off event SNS senses turn-off over-voltages and limits them by AAC to a save value below the semiconductor devices blocking voltage. In case the semiconductor device offers a current-sense terminal, an adjustable over-current detection can be realized as alternative to a short- circuit monitoring. The SIC118xKQ is equipped with an integrated power and voltage failure management. These features control IC power and voltage. It also generates and regulates secondary-side bipolar supply voltage. The input (IN) logic is designed to work directly with controllers using 5 V CMOS logic. It is recommended to use a pull-down resistor close to the input pin. During normal operation, when there is no fault detected, the SO pin stays at high impedance (open drain). Any fault is reported by connecting the SO pin to GND. SO stays low as long as V VCC (primary-side) stays below UVLO VCC . If a short- circuit is detected or the supply voltage VV ISO , (secondary-side) drops below UVLO VISO , the SO status changes with a delay time t FAULT and keeps status low for a time defined as t SO . In case of a fault condition the driver applies the off-state (GL is connected to COM). During the t SO period, command signal transitions from IN are ignored. A new turn-on command transition is required before the driver will enter the on-state. The gate of the semiconductor device to be driven can be connected to the SCALE-iDriver output via GH and GL, using two different resistor values. Turn-on gate resistor R GON needs to be connected to the GH pin and turn-off gate resistor R GOFF to GL. If both gate resistors have the same value, GL and GH can be connected together. The SCALE-iDriver data sheet defines the R GH and R GL values as total resistances connected to the respective GH and GL. In addition to R GINT, external resistor devices R GON and R GOFF are specified to setup the gate current levels to the application requirements. Consequently, R GH is the sum of R GON and R GINT . Careful consideration should be given to the power dissipation and peak current associated with the external gate resistors. The GH pin output current source (I GH ) is capable of handling up to 7.8 A during turn-on, and the GL pin output current source (I GL ) is able to sink up to 7.3 A during turn-off. If the gate resistors for SCALE-iDriver attempt to draw a higher peak Power Integration’s SIC118xKQ SCALE-iDriver™, a high-efficiency, single-channel gate driver for SiC MOSFETs, is now certified to AEC-Q100 for automotive use. Devices can be configured to support gate-drive voltage requirements of commonly used SiC MOSFETs and feature sophisticated safety and protection features. AEC-Q100 certified SiC MOSFET SCALE- iDriver™ PCB for ABB power module