IMP522
P
OWER
M
ANAGEMENT
A
DVANCE
P
RODUCT
I
NFORMATION
Key Features
N
Drive two EL lamps independently
N
Digital LMPSEL pin
鈥?Activate either or both EL output drivers
N
220V
P-P
typical AC output voltage drives
30nF EL lamps
N
Wide operating voltage range: 2V to 6.5V
N
Low current consumption: 2mA maximum
N
Disable mode extends battery life
鈥?Disable current 2碌A maximum
N
Compact 10-pin MicroSO package
N
High-voltage, low-cost CMOS process
Dual EL Lamp Driver
The IMP522 is a dual-output, high-voltage electroluminescent (EL) lamp
driver. Either or both EL lamp driver outputs can be turned ON with the
LMPSEL select pin. One EL lamp is connected between V
A
and V
AB
and
the other is connected between V
B
and V
AB
. V
AB
is a common pin for both
lamps. With an input supply voltage between 2.0V and 6.5V, the typical
regulated lamp drive voltage is 220V peak-to-peak.
The device uses a single inductor and a minimum number of passive
components: a storage capacitor, a fast recovery diode and two resistors
to set the PWM and EL drive frequencies. These can be independently
set to optimize brightness and minimize power consumption. R
SW
is
connected between the R
SW-OSC
pin and the supply pin V
DD
to set the
frequency for the internal 4.0鈩?switching MOSFET. The switch duty cycle
is 88%. The EL lamp driver frequency is set by R
EL
connected between the
R
EL-OSC
pin and the V
DD
pin.
Designed to minimize battery current drain, the IMP522 draws 2mA maxi-
mum. A power-saving shutdown mode reduces current to 2碌A maximum.
The IMP522 is available in a compact 10-pin MicroSO package and in die form.
Applications
N
N
N
N
N
N
Cellular phones
PDAs/Handheld computers
Toys/Consumer electronics
Safety Illumination
LCD modules
Remote controls
L
X
(4)
Block Diagram
(2) R
SW-OSC
V
REF
(1) V
DD
Three-Level Detector
(9) LMPSEL
Select
A Lamp
Select
B Lamp
V
DD
Lamp
Drive
Oscillator
(10) R
EL-OSC
(6) GND
漏 2001 IMP, Inc.
408-432-9100/www.impweb.com
鈥?/div>
V
A
(8)
V
AB
(7)
Dual
Bridge
Driver
V
B
(5)
522_01.eps
Switch
Oscillator
Regulation
Control
+
C
S
(3)
1
1
2
3
4
5
6
