Electrical specification L9915B
14/20 DocID027541 Rev 1
To convert phase frequency (Hz) to rotation speed (rpm) according to alternator poles pair
number (N), use the following equation: rotation speed (rpm) = phase frequency (Hz) * 60 / N.
Principle of phase regulation
When VB is above the set-point voltage, the field driver is controlled to keep phase peak
voltage from falling below VPprTh. If phase peak voltage drops below VPLTh, phase
regulation does not work.
Figure 9. Principle of phase regulation
3.3.5 Pin ‘F’
fP
SS
Self start frequency threshold
-
255 300 345 Hz
fP
LRC
Frequency threshold to exit/enter in
LRC
238 280 322 Hz
VP
prTh
Phase regulation voltage threshold - 6.7 7.7 8.7 V
Table 9. Electrical characteristics - Pin ‘PH’ (continued)
Symbol Parameter Test condition Min Typ Max Unit
'!0'03
6"
T
T
T
,OADREMOVAL
6OLTAGEJUMP
0HASEREGULATIONPULSE
6&
60(
60
PR4H
Table 10. Electrical characteristics - Pin ‘F’
Symbol Parameter Test condition Min Typ Max Unit
VF
sat
Field driver saturation voltage
T
j
= 130 °C; I
sunk
= 4.5 A - - 0.6 V
T
j
= 25 °C; I
sunk
= 7 A - - 0.55 V
VF
diode
Freewheeling diode I
sourced
= 5 A -2 - - V
IF
leak
Field leakage current VB = 24 V; VF = 0 - - 5 μA
IF
OVP
Field driver over-current
protection
T
j
= -40 °C 9 - 15 A
T
j
= 25 °C 8.5 - 15 A
T
j
= 130 °C 8.5 - 15 A
TF
retry
Retry time in case of over-
current
30 40 50 ms
