L9907N
An external resistor R
CF
is recommended be-
tween the slider of the control and feedback po-
tentiometer.
This resistor assures that in the case of input con-
trol or input feedback wire interruption the input
differential voltage will be within the NEUTRAL
ZONE and the motor position remains frozen.
The circuit features an overvoltage disable func-
tion referred to the supply voltage V
S
higher than
18V, both outputs are forced to tristate in this con-
dition.
The thermal overload function disables the out-
puts (tristate) when the junction temperature in-
creases above the thermal shutdown threshold
temperature of min. 150擄C.
For the start of a heavy loaded motor, if the motor
current reaches the max. value it is necessary to
respect the dynamical thermal resistance junction
to ambient. The maximum output current is 0.8A.
The maximum junction temperature in this phase
should not increase above the thermal shutdown
threshold. In case of output disable due to ther-
mal overload the output remains disabled till the
junction temperature decreases under the thermal
enable threshold. This behaviour is assured with
the thermal shutdown hysteresis threshold , which
minimum value is 20擄C.
Figure 3, 5 and 7 show typical application dia-
grams for headlight adjustment applications. To
assure the safety of the circuits in the reverse bat-
tery condition a reverse protection diode D
1
, is
necessary.
The input currents in this condition are limited by
the resistors R
INC
and R
INF
. The transient protec-
tion diode D
2
must assure that the maximum rat-
ing for V
S
during the transients at V
BAT
line will be
limited to a value lower than absolute maximum
Figure 4:
Control to feedbacktransfer characteristic
for proportionalregulation with extended
V
C
operating range:
V
BAT
D95AT185A
V
S
-2V
V
F
1.5V
0
1.5V
V
C
V
S
-2V
V
BAT
Figure 5:
RecommendedApplication Circuit Diagram with L9907Nfor proportionalregulation with extended
R
INC2
鈰?/div>
V
C
:
V
C
operating range. For ideal adjusted condition V
F
=
R
INC1
+
R
INC2
MODULE
V
BAT
D1
I
Q
C
S
R
INC1
V
S
R
PR
I
INC
V
INC
R
INF
V
INF
I
INF
INF
GND
INC
PR
OUT C
R
F
D2
R
C
V
C
R
INC2
L9907N
V
M
OUT F
I
M
M
V
F
D95AT186
Note:
Recommended value of R
INC
, R
INF
(equivalent input resistance to I
NC
and I
NF
) is 5K鈩?to 10K鈩? If the motor should not change its position, when
the control signal wire become open, R
INC1
and R
INC2
should be rated so that V
INC
鈮?/div>
0.4V in this condition.
5/8
1
2
3
4
5
6
7
8
