9.1 Application Information

The UCC21736-Q1 device is very versatile because of the strong drive strength, wide range of output power supply, high isolation ratings, high CMTI and superior protection and sensing features. The 1.5-kVRMS working voltage and 12.8-kVPK surge immunity can support up both SiC MOSFET and IGBT modules with DC bus voltage up to 2121V. The device can be used in both low power and high power applications such as the traction inverter in HEV/EV, on-board charger and charging pile, motor driver, solar inverter, industrial power supplies and etc. The device can drive the high power SiC MOSFET module, IGBT module or paralleled discrete device directly without external buffer drive circuit based on NPN/PNP bipolar transistor in totem-pole structure, which allows the driver to have more control to the power semiconductor and saves the cost and space of the board design. UCC21736-Q1 can also be used to drive very high power modules or paralleled modules with external buffer stage. The input side can support power supply and microcontroller signal from 3.3V to 5V, and the device level shifts the signal to output side through reinforced isolation barrier. The device has wide output power supply range from 13V to 33V and support wide range of negative power supply. This allows the driver to be used in SiC MOSFET applications, IGBT application and many others. The 12V UVLO benefits the power semiconductor with lower conduction loss and improves the system efficiency. As a reinforced isolated single channel driver, the device can be used to drive either a low-side or high-side driver.

UCC21736-Q1 device features extensive protection and monitoring features, which can monitor, report and protect the system from various fault conditions.

• Fast detection and protection for the overcurrent and short circuit fault. The feature is preferable in a split source SiC MOSFET module or a split emitter IGBT module. For the modules with no integrated current mirror or paralleled discrete semiconductors, the traditional desaturation circuit can be modified to implement short circuit protection. The semiconductor is shutdown when the fault is detected and FLTb pin is pulled down to indicate the fault detection. The device is latched unless reset signal is received from the RST/EN pin.
• Soft turn-off feature to protect the power semiconductor from catastrophic breakdown during overcurrent and short circuit fault. The shutdown energy can be controlled while the overshoot of the power semiconductor is limited.
• UVLO detection to protect the semiconductor from excessive conduction loss. Once the device is detected to be in UVLO mode, the output is pulled down and RDY pin indicates the power supply is lost. The device is back to normal operation mode once the power supply is out of the UVLO status. The power good status can be monitored from the RDY pin.
• Active short circuit feature creates phase to phase short circuit in three-phase inverter to protect the battery from overvoltage breakdown.
• The active miller clamp feature protects the power semiconductor from false turn on by driving an external MOSFET. This feature allows the flexibility of the board layout design and the pulldown strength of miller clamp FET.
• Enable and disable function through the RSTb/EN pin.
• Short circuit clamping.
• Active pulldown.