Datasheet IMP522EMB Datasheet (IMP)

© 2001 IMP, Inc. 408-432-9100/www.impweb.com 1

IMP522

IMP522

POWER MANAGEMENT ADVANCE PRODUCT INFORMATION

Dual EL Lam

Dual EL Lam

p Dr

p Driviverer

◆ Cellular phones

◆ PDAs/Handheld computers

◆ Toys/Consumer electronics

◆ Safety Illumination

◆ LCD modules

◆ Remote controls

◆ Drive two EL lamps independently

◆ Digital LMPSEL pin

— Activate either or both EL output drivers

◆ 220V

P-P

typical AC output voltage drives

30nF EL lamps

◆ Wide operating voltage range: 2V to 6.5V

◆ Low current consumption: 2mA maximum

◆ Disable mode extends battery life

— Disable current 2µA maximum

◆ Compact 10-pin MicroSO package

◆ High-voltage, low-cost CMOS process

Key Features

Applications

522_01.eps

–

+

Lamp
Drive

Oscillator

Three-Level Detector

Select

A Lamp

Select

B Lamp

Switch

Oscillator

V

REF

(2) R

SW-OSC

LX (4)

C

S

(3)

V

A

(8)

V

AB

(7)

V

B

(5)

Dual

Bridge

Driver

V

DD

Regulation

Control

(1) V

DD

(9) LMPSEL

(10) R

EL-OSC

(6) GND

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 VABand

the other is connected between V

B

and VAB. VABis 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 VDDto 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 VDDpin.

Designed to minimize battery current drain, the IMP522 draws 2mA maxi­mum. 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

IMP522

IMP522

2 408-432-9100/www.impweb.com © 2001 IMP, Inc.

Parameter Symbol Conditions Min Typ Max Units

ON-resistance of MOS Switch R

DS(ON)

I = 100mA 4.0 8.0 Ω

Output Voltage Regulation V

CS

VDD= 2.0 to 6.5V, 110 120 V
T = –40°C to 85°C

Output Voltage Peak-to-Peak (in regulation) VA-V

AB, VB-VAB

In Regulation 220 V

Input Current at VDDPin I

DD

LMPSEL = GND 650 µA

Powerdown Input Current I

DDQ

V

RSW–OSC

< 100mA 2 µA

V

DD

= 2.0 to 6.5

T = –40°C to 85°C

Input Crrent Plus Inductor Current I

IN

See Figure 1 30 mA
LMPSEL = GND or V

DD

LMPSEL = floating 43 mA

Output Drive Frequency f

EL

See Figure 1 250 Hz

Switching Frequency f

SW

See Figure 1 61 kHz

Switching Duty Cycle D

SW

See Figure 1 88 %

LMPSEL Low-Level Threshold V

IL

0.3 V

DD

V

LMPSEL High-Level Threshold V

IH

0.7 V

DD

V

LMPSEL Input Resistance R

LMPSEL

50 kΩ

LMPSEL Sink/Source Resistance I

LMPSEL

Floating/Hign Impedance State ± 5µA

LMPSEL Hysteresis V

hys

50 mV

4L

X

3C

S

2R

SW-OSC

1V

DD

7

LMPSEL

5V

B

6 GND

8

V

AB

9

V

A

10 R

EL-OSC

522_02.eps

IMP522

MicroSO

Part Number Input Voltage Temperature Range Pins- Package

IMP522EMB 2.0V to 6.5V –40°C to +85°C 10-MicroSO

VDD, R

SW-OSC

and R

EL-OSC

. . . . . . . . . . . . . . . . . –0.5V to +7.0V

C

S

, LX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5V to +120V

Operating Temperature Range . . . . . . . . . . . . –40°C to +85°C

Storage Temperature Range . . . . . . . . . . . . . . –65°C to +150°C

Power Dissipation (MicroSO) . . . . . . . . . . . . . 500mW

V

A

, V

B, VAB

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5V to VCS(pin 3)

Unless otherwise noted, VDD= 3.0V, RSW= 910kΩ, REL= 2.7MΩ, L = 220µH 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.

Add /T to ordering part number for Tape and Reel.

Ordering Information

Pin Configuration

Absolute Maximum Ratings

Electrical Characteristics

IMP522

IMP522

© 2001 IMP, Inc. Electroluminescent Lamp Drivers 3

Pin Descriptions

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Figure 1. Test Circuit

Application Information

+

–

+

V

DD

R

SW-OSC

C

S

L

X

R

EL-OSC

V

A

V

AB

LMPSEL

V

B

GND

10

9

8

7

EL LAMP
10nF

EL LAMP
10nF

1

2

3

4

65

IMP522

R

EL

Enable/Disable Strobe

V

DD

FDLL400

L

522_04.eps

ON = V

DD

OFF = 0V

R

SW

C

S

0.1µF10µF

L = 220µH

R

EL

= 2.7MΩ

R

SW

= 910kΩ

IMP522

IMP522

4 408-432-9100/www.impweb.com © 2001 IMP, Inc.

Application Information

EL Lamp Drive

The outputs VA– VABand VB– VABare configured as H-bridges,
driven by the EL oscillator. Each output is switched between C

S

and ground on alternate phases, creating peak-to-peak signals
across the EL lamps of twice the regulated voltage.

EL Lamp Selection: LMPSEL

The digital input pin LMPSEL allows either or both EL lamps to
be active. Lamp A is active when LMPSEL is LOW and lamp B is
active when LMPSEL is HIGH. When LMPSEL is left floating or
driven by a three-state driver in the high impedance state, both
lamp driver outputs are active.

The logic HIGH signal level is defined as greater than 0.7V

DD

and

logic LOW is defined as less than 0.3V

DD

. A floating level is rec-

ognized with the signal level between 0.3V

DD

and 0.7VDD, or
when the output impedance of the driving voltage signal source
is infinite (driver in OFF state).

Both drivers are OFF if the IMP522 is disabled.

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EL Driver Output Overvoltage Regulator

The IMP522 maximum VCSoutput voltage is between 110V and
120V. The internal overvoltage regulator skips the inductor
switching whenever the voltage on the C

S

pin exceeds the regula­tion threshold. The internal overvoltage detection trip point has a
hysterisis of 1V and a range of 110V to 120V at room temperature.

PWM Circuit Switching

The switching MOSFET is driven by the PWM signal (nominally
61kHz). During the first 88% of the period, the switch is ON,
providing a low impedance path (<8Ω) from L

X

to ground. This
causes the external inductor to charge. In the last 12% of the
period, the MOSFET is turned OFF. This causes the voltage on
the output of L

X

to rise up to a high value. At some point, this will
forward-bias the external diode, thus pumping charge into the
storage capacitor C

S

. The voltage on CSincreases each cycle to
between 110V and 120V. When the internal regulation trip-point is
reached, the overvoltage regulator turns the MOSFET switch OFF
to conserve power.

IMP522

IMP522

© 2001 IMP, Inc. Electroluminescent Lamp Drivers 5

Power Sequencing

To power up the chip, the R

SW-OSC

pin is connected to VDDthrough

the external R

SW

resistor. The voltage on the pin will charge up to

V

DD

/2. An internal threshold detector circuit monitors the pin
voltage and when it exceeds the threshold range (0.2V to 0.9V) it
powers up the oscillator and internal bias modules. This starts a
delay counter which is one half of the EL oscillator period, after
which power to the high voltage internal modules is applied. The
IMP522 is then operating fully.

To power down the chip, R

SW

is driven to ground via a switch or
logic gate. When the voltage on the driver side of the resistor falls
below V

DD

/2, there will be no input bias current into the R

SW-OSC

pin. This immediately powers down the internal high-voltage
circuits, which effectively shuts the lamp off. At this point the
oscillator and bias modules still draw quiescent current, but oscil­lations have ceased. As the R

SW-OSC

pin voltage falls below 0.1, the

oscillator and bias modules are also fully powered down.

Figure 1. Driver Waveforms

522_03.eps

IN (Pulse)

I

LX

V

LX

Power Saving Disable Mode

The IMP522 can be powered up and down with R

SW-OSC

. In

normal operation, this resistor on the R

SW-OSC

pin is connected to

V

DD

or another voltage source. To power down (disable) the

IMP522, R

SW

is connected to ground.

When disabled, the IMP522 quiescent current drops to typically 20nA.

In die form, an extra pin ENABLE is available (contact factory).
Connecting this pad to V

DD

disables the chip. The ENABLE signal

can be driven by a microcontroller.

Oscillator Frequency Adjustment

The EL lamp drive and PWM boost converter oscillation frequen­cies can be programmed independently.

The R

SW

resistor, connected between the R

SW-OSC

pin and VDD,
determines the Inductor Switching (or PWM-) frequency. For the
recommended nominal resistor value of 910kΩ, the frequency is
61kHz. For other resistor values, the frequency is inversely pro­portional to the resistor value. Increasing the resistance will lower
the frequency.

The R

EL

resistor, connected between the R

EL-OSC

pin and VDD,
determines the EL lamp drive frequency. For the recommended
nominal resistor value of 2.7MΩ, the frequency is 250Hz. For
other resistor values, the frequency is inversely proportional to
the resistor value: increasing the resistance will lower the fre­quency.

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Application Information

IMP, Inc.
Corporate Headquarters
2830 N. First Street
San Jose, CA 95134-2071
Tel: [phone]
Fax: [phone]
e-mail: [e-mail]
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.

©

2001 IMP, Inc.
Printed in USA
Publication #: 2007
Revision: E
Issue Date: 03/16/01
Type: Advance Info

IMP522

IMP522

Package Dimensions

e

b

D

E1 E

a

L

+

C

D

0.10mm

0.004in

A1

A2

A

MicroSO (10-Pin).eps

MicroSO (10-Pin)

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1A0200.09500.0050.051.0

2A7030.00730.087.049.0
b9500.08900.051.052.0
C1500.01900.031.032.0
D2411.00221.009.201.3
eCSB7910.0CSB05.0
E0991.01781.050.550.5

1E2411.00221.009.201.3
L7510.06720.004.007.0
a °0 °6 °0 °6

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θ

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14 ° W/C

θ

AJ

311 ° W/C

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