MC33927 Datasheet, PDF (36/44 Pages) Freescale Semiconductor, Inc – Three-Phase Field Effect Transistor Pre-Driver

FUNCTIONAL DEVICE OPERATION
PROTECTION AND DIAGNOSIS FEATURES
PROTECTION AND DIAGNOSIS FEATURES
Table 18. 33927 Fault Protection
No.
Fault
Cause
Detection
33927 Protective Action
1
Phase Output
Wire harness shorted to ^{• Directly sensed by ADC as}
Shorted to VBAT
(High-Side FET
Shorted)
battery
voltage across R_SENSE
• All external FETs turned off
Drain-to-Source short on the ^{• Overcurrent Comparator output} _{• Fault bit set in Status Register}
High-Side FET
OC_OUT monitoring
(Overcurrent Error)
• INT pin set high
• Low-Side Phase Error
• OC_OUT pin set high
• Direct PHASEx output
monitoring
2
Phase Output
Wire harness shorted to ^{• Desaturation Error}
Shorted to
battery
• High-Side Phase Error
Ground (R_SENSE
Bypassed)
• Direct PHASEx output
monitoring
• All external FETs turned off
• Fault bit set in Status Register
• INT pin set high
3
Low-Side FET
Drain-to-Source short on the ^{• Directly sensed by the ADC as}
Shorted
Low-Side FET
voltage across R_SENSE
• Overcurrent Comparator output ^{• All external FETs turned off}
OC_OUT high (Overcurrent • Fault bit set in Status Register
error)
• INT pin set high
• Desaturation Error
• OC_OUT pin set high
• High-Side Phase Error
• Direct PHASEx output
monitoring
4
High-Side FET
Module board assembly _{• Desaturation Error}
Opened
issue
• High-Side Phase Error
• All external FETs turned off
• Fault bit set in Status Register
• INT pin set high
5
Low-Side FET
Module board assembly ^{• Directly sensed by ADC as}
• All external FETs turned off
Opened
issue
voltage across R_SENSE
• Fault bit set in Status Register
• Low-Side Phase Error
• INT pin set high
6
Phase Output
Opened (No
Load)
Wire harness open
• Directly sensed by ADC as
voltage across R_SENSE
NOTE: Other protective actions should be taken at the system level by the controlling microcontroller or DSP. It is possible
to disable all automatic shutdowns except for VLS undervoltage. Even when masked, faults will be registered by the status
registers.
33927
36
Analog Integrated Circuit Device Data
Freescale Semiconductor