IMP522 Datasheet, PDF (1/6 Pages) IMP, Inc – Dual EL Lamp Driver

IMP522
POWER MANAGEMENT
ADVANCE PRODUCT INFORMATION
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 4.0Ω 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 2µA maximum.
The IMP522 is available in a compact 10-pin MicroSO package and in die form.
Block Diagram
Key Features
N Drive two EL lamps independently
N Digital LMPSEL pin
— 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
— Disable current 2µA maximum
N Compact 10-pin MicroSO package
N High-voltage, low-cost CMOS process
Applications
N Cellular phones
N PDAs/Handheld computers
N Toys/Consumer electronics
N Safety Illumination
N LCD modules
N Remote controls
L_X (4)
(2) R_SW-OSC
Switch
Oscillator
Regulation
Control
C_S (3)
(1) V_DD
(9) LMPSEL
V_REF
Select
A Lamp
Three-Level Detector _Select
B Lamp
V_DD
Dual
Bridge
Driver
V_A (8)
V_AB (7)
(10) R_EL-OSC
(6) GND
© 2001 IMP, Inc.
Lamp
Drive
Oscillator
408-432-9100/www.impweb.com
V_B (5)
522_01.eps
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