Page 1
© 2001 IMP, Inc. 408-432-9100/www.impweb.com 1
IMP528
IMP528
POWER MANAGEMENT
Block Diagram
High-
High-VV
olt
olt
ag
ag
e EL Lam
e EL Lam
p Dr
p Driviverer
– 220 V
– 220 V
PP
PP
DrDrivive
e
◆ GPS units/Pagers/Cellular phones
◆ PDAs/Handheld computers
◆ Safety illumination
◆ Portable instrumentation
◆ Battery-operated displays
◆ LCD modules
◆ Toys
◆ 220V peak-to-peak typical AC output voltage
◆ Low Power: 420µA typical V
DD
current
◆ Wide operating voltage range -from 2.0V to 6.5V
◆ Large output load capability - drives lamps
with more than 50nF capacitance
◆ Eliminates external protection resistor in series
with EL lamp
◆ Adjustable output lamp frequency for control of
lamp color, lamp life, and power consumption
◆ Adjustable converter frequency to minimize
power consumption
◆ High-Voltage CMOS Process
◆ MicroSO package option
Key Features
Applications
–
+
528_01.eps
V
DD
1
L
X
4
C
S
3
V
A
7
V
B
6
R
SW-OSC
2
Switch
Oscillator
Regulation
Control
IMP528
Bridge
Output
Driver
Q
Q
Q
V
REF
Lamp Drive
Oscillator
C
GND
5
R
EL-OSC
8
Q
The IMP528 is an Electroluminescent (EL) lamp driver with the four EL
lamp driving functions on-chip. These are the switch-mode power supply, its high-frequency oscillator, the high-voltage H-bridge lamp driver
and its low-frequency oscillator. The IMP528 drives EL lamps of up to
50nF capacitance to high brightness; EL lamps with capacitances greater
than 50nF can be driven, but will be lower in light output. The typical
regulated output voltage that is applied to the EL lamp is 220V peak-topeak. The circuit requires few external components; a single inductor,
single diode, two capacitors and two resistors. Two of these resistors
set the frequency for two internal oscillators.
Unlike other EL lamp drivers, the IMP528 does not require an external
protection resistor in series with the EL lamp.
The IMP528 operates over a 2.0V to 6.5V supply voltage range. A
regulated, low-power source can supply the low quiescent current of the
IMP528. The inductor may be driven from an independent, unregulated
supply voltage in dual supply applications.
An internal circuit shuts down the switching regulator when the lamp
drive voltage reaches 220V peak-to-peak. This conserves power and
extends battery life.
The IMP528 is available in MicroSO and SO-8 packages and in die or
wafer form.
Page 2
IMP528
IMP528
2 408-432-9100/www.impweb.com © 2001 IMP, Inc.
Electrical Characteristics
Absolute Maximum Ratings
Ordering Information
Pin Configuration
Parameter Symbol Conditions Min Typ Max Units
ON-resistance of MOS Switch R
DS(ON)
I = 100mA 3.0 8 Ω
Output Voltage Regulation V
CS
VDD= 2.0 to 6.5V 110 V
Output Voltage Peak-to-peak (in regulation) VA-V
B
VDD= 2.0 to 6.5V 220 V
Input Current at VDDPin I
DD
VDD= 3.0V, See Figure 1 420 700 µA
Input Current at VDDPin I
DD
VDD= 5.0V 500 750 µA
Quiescent VDDSupply Current, Disabled I
DDQ
V
RSW-OSC
< 100mV 20 200 nA
Input Current: IDDPlus Inductor Current I
IN
VDD= 3.0V, See Figure 1 21 31 mA
V
A-B
Output Drive Frequency f
EL
VDD= 3.0V, See Figure 1 250 Hz
Switching Frequency f
SW
VDD= 3.0V, See Figure 1 61 kHz
Switching Duty Cycle D
SW
VDD= 3.0V, See Figure 1 88 %
4L
X
3C
S
2R
SW-OSC
1V
DD
5 GND
6V
B
7V
A
8R
EL-OSC
528_02.eps
IMP528
SO/ MicroSO
Part Number Input Voltage Regulated Output Voltage Temperature Range Pins-Package
IMP528ESA 2.0V to 6.5V Yes – 40°C to +85°C 8-SO
IMP528EMA 2.0V to 6.5V Yes – 40°C to +85°C 8-MicroSO
IMP528/D* 2.0V to 6.5V Yes 25°C Dice
IMP528/D1** 2.0V to 6.5V Yes 25°C Dice
VDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5V to +7.0V
V
RSW-OSC
and V
REL-OSC
. . . . . . . . . . . . . . . . . . . –0.5V to V
DD
+0.3V
V
CS
, LX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5V to +120V
Operating Temperature Range . . . . . . . . . . . . –40°C to +85°C
Storage Temperature Range . . . . . . . . . . . . . . –65°C to +150°C
Power Dissipation (SO) . . . . . . . . . . . . . . . . . . 400mW
Power Dissipation (MicroSO) . . . . . . . . . . . . . 300mW
V
A
, VB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5V to VCS(pin 3)
Unless otherwise noted, VDD= 3.0V, RSW= 910kΩ, REL= 2.7MΩ, and TA= 25°C.
Note: All voltages are referenced to GND.
These are stress ratings only and functional operation is not
implied. Exposure to absolute maximum ratings for prolonged
time periods may affect device reliability.
Pin Compatible With IMP803 and IMP560
* Disable pad not active
** Disable pad active
Add /T to ordering part number for Tape and Reel.
Page 3
IMP528
IMP528
© 2001 IMP, Inc.
Electroluminescent Lamp Driver
3
Pin Descriptions
External Components
Pin Number Name Function
1V
DD
Positive voltage supply for the IMP528. Inductor L may be connected here or to a
separate unregulated supply.
2R
SW-OSC
Switch-mode resistor pin. Switching frequency is determined by an external resistor, RSW.
3C
S
Boost converter storage capacitor. The voltage across the EL lamp is equal to twice the
voltage at CS.
4L
X
Connection to flyback inductance, L.
5 GND Ground pin.
6V
B
EL lamp drive. The lamp is connected in a high-voltage bridge circuit with VBproviding
the complementary connection to V
A
. The peak-to-peak AC voltage across the EL lamp is
thus two times VCS.
7V
A
EL lamp drive. (See above)
8R
EL-OSC
The EL lamp oscillator frequency setting pin. The oscillator frequency is controlled
by external resistor R
EL
.
External Component Description and Selection Guide
Diode Catch diode. A fast reverse recovery diode, with BV > 150V, such as an FDLL400 (150V).
Capacitor C
S
This is the high voltage capacitor that stores the inductive energy transferred through the
catch diode. A capacitor with WV > 120V between 10nF and 100nF is recommended.
Resistor R
EL
The EL lamp oscillator frequency setting resistor. This resistor, connected between the
R
EL-OSC
pin and VDD, provides an oscillator frequency inversely proportional to REL;
as RELincreases, the EL lamp frequency decreases along with the current drawn by the lamp.
Lamp color is also determined by this frequency. A 2.7MΩ resistor between the R
EL-OSC
pin and
the VDDsupply results in a lamp frequency around 250Hz.
Resistor R
SW
Switching Oscillator frequency setting resistor. The switching oscillator resistor is connected
between the R
SW-OSC
pin and the VDDsupply. The switching frequency is inversely proportional
to the resistor value, dropping as the resistance increases.
Inductor L The inductor provides the voltage boost needed by means of inductive “flyback”. The internal
MOSFET switch alternately opens and closes the ground connection for the inductor at the
LXpin. When this internal switch opens, the inductor potential will forward-bias the catch
diode and the current will pass through the storage capacitor CS, charging it to a high voltage.
Smaller inductors are preferred to prevent saturation. As the value of the inductor
increases (and the series DC resistance of the inductor decreases), the switching frequency
set by R
SW
should be increased to prevent saturation. In general, smaller value inductors that
can handle more current are more desirable when larger area EL lamps must be driven.
Page 4
IMP528
IMP528
4 408-432-9100/www.impweb.com © 2001 IMP, Inc.
+
–
V
DD
R
SW-OSC
C
S
L
X
R
EL-OSC
V
A
V
B
GND
8
7
6
5
1
2
3
4
IMP528
2.7MΩ
R
EL
910kΩ
220µH
1
VIN = 3.0V
0.1µF
2
FDLL400
L
LEN
3
EL lamp
10nF
(3 in2 lamp)
Note:
1. Murata part # LQH4N221K04 (DC resistance <5Ω)
2. Larger values may be required depending upon supply impedance.
3. EN is connected to VDD to enable and to GND to disable.
528_03.eps
10nF
200V
R
SW
C
S
Figure 1. 3.0V Application
Test and Application Circuit, 3.0V
Figure 1 shows the IMP528 configured to drive an EL lamp with a
3.0V input.
Dual Supply Operation with 1.5V Battery
The IMP528 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 2, uses the regulated
voltage to operate the IMP528 while the energy for the highvoltage boost circuit comes from the battery.
+
–
EN
2
V
DD
R
SW-OSC
C
S
L
X
R
EL-OSC
V
A
V
B
GND
8
7
6
5
1
2
3
4
IMP528
R
EL
Regulated Voltage
(2.0V to 6.5V)
R
SW
V
IN
L
Battery
Voltage
0.1µF
1
FDLL400
EL lamp
528_04.eps
1. Larger values may be required depending upon supply impedance.
2. EN is connected to VDD to enable and to GND to disable.
10nF
200V
C
S
Figure 2. Dual Supply Operation
Application Information
Page 5
IMP528
IMP528
© 2001 IMP, Inc.
Electroluminescent Lamp Driver
5
High–Voltages Present
Switch Resistance
The IMP528 inductor switch resistance is typically below 3.5Ω, as
shown in Figure 3.
On Resistance (Ω)
VDD (V)
528_05.eps
1234567
0
5
10
15
20
25
30
Figure 3. Boost Switch ON-Resistance
The IMP528 generates high voltages and caution should
be exercised.
Page 6
IMP, Inc.
Corporate Headquarters
2830 N. First Street
San Jose, CA 95134-2071
Tel: 408-432-9100
Fax: 408-434-0335
e-mail: [email protected]
http://www.impweb.com
The IMP logo is a registered trademark of IMP, Inc.
All other company and product names are trademarks of their respective owners.
© 2000 IMP, Inc.
Printed in USA
Publication #: 2004
Revision: C
Issue Date: 04/13/01
Type: Product
IMP528
IMP528
SO (8-Pin)
Package Dimensions
MicroSO (8-Pin)
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niMxaMniMxaM
*)niP-8(OS
A350.0960.053.157.1
1A400.0010.001.052.0
B310.0020.033.015.0
C700.0010.091.052.0
e050.072.1
E051.0751.008.300.4
H822.0442.008.502.6
L610.0050.004.072.1
D981.0791.008.400.2
**)niP-8(OSorciM
A ––––– 3340.0 –––– 01.1
1A0200.09500.0050.051.0
2A5920.04730.057.059.0
b8900.07510.052.004.0
C1500.01900.031.032.0
D2411.00221.009.201.3
eCSB6520.0CSB56.0
ECSB391.0CSB09.4
1E2411.00221.009.201.3
L7510.06720.004.007.0
a °0 °6 °0 °6
AA210-SMgniwarDCEDEJ*
AA781-OMgniwarDCEDEJ**
3ta.10t_825
0°– 8°
L
H
E
D
A
e
B
A1
E1 E
D
e
A2
A
0.10mm
D
0.004in
A1
b
C
SO (8-Pin).eps
a
+
C
MicroSO (8-Pin).eps
L
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