SLUA963B June 2020 – October 2022 UCC21710-Q1 , UCC21732-Q1 , UCC5870-Q1
The system impact of various failures are shown as given in Table 2-2 may be prevented using integrated and auxiliary circuits around the gate driver. Table 3-1 shows these system impacts and potential failures along with the integrated and auxiliary circuits of the gate driver circuitry that can be used to prevent them.
The potential failure location(s) within the system block are as shown in Figure 3-2, classified as (F1) PMIC failure, (F2) MCU failure, (F3) Driver failure, or (F4) Motor/Mechanical failure.
System impact | Associated driver and/or inverter failures | Potential failure location(s) | UCC217xx-Q1 integrated features | External circuit features |
---|---|---|---|---|
Torque disturbance | Over or under voltage of driver power supply | F1 | UVLO + interrupt signal | OVLO + interrupt signal |
Unintended commutation | Gate driver pulse width skew | F2 or F3 | Low-delay capacitive isolation barrier and proven process | N/A |
Unintended motor shutdown / Torque disturbance | Power switch short circuit | F2 or F4 | DESAT/OC detection and interrupt | DESAT (UCC21750) or OC (UCC21732/10) self-test UVLO/OVLO self-test |
Unintended motor shutdown / Torque disturbance | Gate shorted to ground or VDD | F2 or F3 | N/A | VGE monitoring and compare to PWM with interrupt |
Unintended motor shutdown | Power switch shoot-through due to false gate signal or dv/dt-induced current | F2 | Anti-shoot-through logic and Miller clamp (internal or external | N/A |
Torque disturbance | Power switch over-voltage | F2 | Two-level turn-off and/or soft turn-off | VCE/VDS monitoring |
Torque disturbance | Power switch over-temperature | F1, F2, or F4 | Integrated isolated sensing with integrated bias current | N/A |
Torque disturbance | Power switch gate oxide breakdown | F2 or F4 | Short circuit clamping to VDD | N/A |
Torque disturbance | Power switch false turn-on when input power is floating | F1 or F2 | Active pulldown | N/A |
Torque disturbance / Unintended motor shutdown | Power system DC bus over/under voltage | F1 or F4 | Integrated isolated sensing | N/A |