Analog Integrated Circuit Device Data

Freescale Semiconductor

39

33937

FUNCTIONAL DEVICE OPERATION

PROTECTION AND DIAGNOSIS FEATURES

PROTECTION AND DIAGNOSIS FEATURES

Table 18. 33937 Fault Protection

No.

Fault

Cause

Detection

33937 Protective Action

1

Phase Output

Shorted to VSUP

(High Side FET

Shorted)

Wire harness shorted to

battery

Drain-to-Source short on the

High Side FET

• Directly sensed by ADC as voltage

• Over-current Comparator output

OC_OUT monitoring (Over-current

Error)

• Low Side Phase Error

• Direct PHASEx output monitoring

• All external FETs turned off

• Fault bit set in Status Register

• INT pin set high

• OC_OUT pin set high

2

Phase Output

Shorted to

Bypassed)

Wire harness shorted to

battery

• Desaturation Error

• High Side Phase Error

• Direct PHASEx output monitoring

• All external FETs turned off

• Fault bit set in Status Register

• INT pin set high

3

Low Side FET

Shorted

Drain-to-Source short on the

Low Side FET

• Directly sensed by the ADC as

• Over-current Comparator output

OC_OUT high (Over-current error)

• Desaturation Error

• High Side Phase Error

• Direct PHASEx output monitoring

• All external FETs turned off

• Fault bit set in Status Register

• INT pin set high

• OC_OUT pin set high

4

High Side FET

Opened

Module board assembly

issue

• Desaturation Error

• High Side Phase Error

• All external FETs turned off

• Fault bit set in Status Register

• INT pin set high

5

Low Side FET

Opened

Module board assembly

issue

• Directly sensed by ADC as voltage

• Low Side Phase Error

• All external FETs turned off

• Fault bit set in Status Register

• INT pin set high

6

Phase Output

Opened (No

Load)

Wire harness open

• Directly sensed by ADC as voltage

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.