IMP803
Dual Supply Operation with 1.5V Battery
The circuit of Figure 5 thus allows operation with batteries that are
below the 2V minimum specification or above the 6.0V maximum
operating voltage.
The IMP803 can also be operate from a single battery cell when a
regulated voltage higher than 2.0V is also available. This dual
supply configuration, shown in Figure 5, uses the regulated
voltage to operate the IMP803 while the energy for the high-
voltage boost circuit comes from the battery.
Regulated Voltage
(2.0V to 6.5V)
ON = VDD
OFF = 0V
REL
1
VDD
RSW-OSC
CS
REL-OSC
8
7
6
5
RSW
RCL
L
2
3
4
V
A
EL lamp
VB
1N4148
CS
+
Battery
Voltage
LX
GND
VIN
–
0.1µF
100V
0.1µF*
IMP803
* Larger values may be required
depending upon supply impedance
803_13.eps
Figure 5. Dual Supply Operation
Switch Resistance
30
The IMP803 inductor switch resistance is typically below 3.5Ω, as
shown in Figure 6.
25
20
15
10
5
0
1
2
3
4
5
6
7
V
(V)
525_14.eps
DD
Figure 6. Boost Switch On Resistance
© 2000 IMP, Inc.
Electroluminescent Lamp Driver
7
IMP [ IMP, INC ]
