l9468 STMicroelectronics, l9468 Datasheet - Page 5

• Manufacturer Part Number: l9468
• Description: All Silicon Voltage Regulator
• Manufacturer: STMicroelectronics

3
The following table lists the conditions that cause the fault lamp driver to function. To prevent lamp flicker, spe-
cific faults are required to be present for TDELAY seconds before the lamp driver is activated. This delay is
indicated in the table.
Table 7.
Table 8. Regulation Features
Notes:
1. Key-on (wiring check), lamp stays on for 1 ± 0.15 sec regardless
2. V
3. V
4. Phase Voltage < VP2 AND VGO / S < setpoint
5. Phase frequency < f
6. No connection between Battery and VGO
7. FAILSAFE
Symbol
FSDF
V
V
other conditions
LRC
I
f
V
V
f
LON
LRC
IFR
LON
LCB
GO
GO
I
FAULT
P1
P2
6.
7.
8.
9.
10. Cut-back occurs when both the "L" and "I" terminals are LOW . If the "I" terminal is disconnected it will assume a logic LOW
P
/ S> V
/ S < undervoltage threshold voltage AND Phase frequency > f
Lamp and Ignition are cooperative. Either can turn on the device when the other is left open or held low. When both go below
their minimum thresholds the L9468 goes into "L" Terminal Control (LTC). The L9468 will remain in LTC until the phase (P) voltage
drops below VP2 and the frequency drops below fIRF at the VP1 threshold then the L9468 is disabled.
This threshold on the phase signal is used to detect the phase frequency, fIFR, for the Initiation of field regulation.
This threshold on the phase signal is used to sense the presence of the phase for fault detection purposes.
This is the time duration the L9468 takes to rump up from 0 % to 100% duty cycle in response to an increased load on the enerator.
The LRC ratio is set 1:4 and the Vreg comparator status is latched at foundamental frequency rate.
allowing the "L" terminal to perform the function alone. In cut-back, to prevent the loss of phase signal, a 31.25% duty cycle is
applied to field output when phase drops below Vp2
Lamp term turn on threshold
Lamp term current sensitivity
Initiation of regulation detection
phase voltage threshold
Fault detection phase voltage
threshold
Sinking current @ P terminal
Initiation of field regulation
frequency
Field Strobe Duty Factor
Load Response Control rate
LRC transition frequency
"L" term. Cut-Back Setpoint
OV
8
Parameter
IFR
7
9
6
V
I
V
@ "power up" with f
LRC is enabled below this value
"L" = 0V, "I" = 0V
Conditions
P
L
P
= 1mA (sinking current)
= 1.5V
= 1 V to Vsp
Test Condition
10
PHASE
LRC
< f
IFR
53.04
2.125
263.5
Min.
20%
0.09
V
0.8
2.5
0.5
7
S
-
31.25
Typ.
25%
310
V
2.5
61
1
3
8
1
S
-
V
70.15
2.875
356.5
Max.
S
1.15
0.78
3.5
1.8
-30%
9
Delay
Yes
Yes
Yes
Yes
Yes
No
No
L9468
Unit
mA
mA
Hz
Hz
%
V
V
V
V
s
5/8