Electrical specification

L9911

16/20

DocID10990 Rev 13

Note:

The diagnostic result is disabled during the Soft-start delay time t_ST 0...3 and the soft-start

/ soft attack timing t_SL 0...3

Figure 14. DF monitor electrical configuration

Figure 15. Short circuit drivers' protection

Field driver, DFMon driver and Relay driver are protected in switching mode (not linear),

with a retry time less than 25 ms.

Lamp driver is protected in linear mode, with a retry time of 1 s.

Table 10. Fault detection

Root cause

Signal

Effect

Test detect

Alternator belt breaking

P

Alternator disexcitation

VP<VPHH1 & VB+<Vreg

Brushes open

P

Alternator disexcitation

VP<VPHH1 & VB+<Vreg

Field driver open

P

Alternator disexcitation

VP<VPHH1 & VB+<Vreg

Field interruption

P

Alternator disexcitation

VP<VPHH1 & VB+<Vreg

Field short circuit to the battery

F+

Overvoltage

VF+>VS1 & VB+ > Vov-d

Field short circuit to the ground

P

Alternator disexcitation

VP<VPHH1 & VB+<Vreg

Battery discharge

B+

Undervoltage

VB+<Vuv