The UCC21732 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 so on. 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. The UCC21732 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 3.3 V to 5 V, and the device level
shifts the signal to output side through reinforced isolation barrier. The device
has wide output power supply range from 13 V to 33 V 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 12-V 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.
The UCC21732 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.
- 2-level 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.
- Analog signal seensing with isolated analog to PWM signal feature. This feature
allows the device to sense the temperature of the semiconductor from the thermal
diode or temperature sensing resistor, or dc bus voltage with resistor divider.
A PWM signal is generated on the low voltage side with reinforced isolated from
the high voltage side. The signal can be fed back to the microcontroller for the
temperature monitoring, voltage monitoring and so on.
- 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