26

NXP Semiconductors

80310

5.9

Protection and diagnosis features

5.9.1

Fault detection

General Notes

All fault reporting passes through a 400 ms digital filter to avoid false indication problems, and transition from one fault type to another

should be “clean”.

5.9.2

Mechanical fault (F_MEC)

The phase is off (Low Phase RPM below stop_regulation threshold). Reported in Alternator A/B read data field (ID=11, 13), byte 1.

5.9.3

Electrical fault (F_EL)

If one of these faults appear:

• The number of “1”s in all the OTP bits, NVM[80:1] is not ODD. The parity bit is included in the calculation

• The Phase is on (Low Phase RPM above stop_regulation threshold) but High Phase 1 is not detected

• B+A reaches 16.5 V with EXC at 100% DC

• Short circuit excitation load

• B+A stays at 75% of the target voltage when LRC is off

Note: This 5th additional condition is enabled only when the NVM bit “Low Voltage Threshold” is enabled. Reported in Alternator A/B

read data field (ID=11, 13), byte 1.

5.9.4

Electrical fault (HP Mask)

A fault detection when High phase signal is cut is reported on the electrical fault. Option (OTP) available to remove this fault detection.

5.9.5

Thermal fault (F_HT)

A thermal fault is reported when the die temperature exceeds the programmed threshold. Reported in Alternator A/B read data field

(ID=11, 13), byte 1.

The programmed threshold in hexadecimal corresponds to the following temperature in degrees:

• 6'b110010;//135degres

• 6'b110100;//145degres

• 6'b110110;//150degres

• 6'b111001;//160degres

5.9.6

Additional errors

LIN bus timeout

Check two timeouts:

• Activity on RXD is below 3 or 8 seconds (depending on the OTP bit)

• Time between two consecutive valid messages is below 3 or 8 seconds (depending on the OTP bit)

This flag is reset once the microcontroller sends MID 11 for ALTA, or MID 13 for Alt B. Reported in Alternator A/B read data field (ID=11,

13), byte 2.

Comm error

Checks the ID parity bits + Checksum byte + (TXD = RXD when responding) + LIN Physical layout not in over-current limitation. Reported

in Alternator A/B read data field (ID=11, 13), byte 2.