IMP IMP527EMA, IMP527ESA Datasheet

© 2000 IMP, Inc. 408-432-9100/www.impweb.com 1

IMP52

IMP5277

POWER MANAGEMENT

Sing

Sing

le Cell Batt

le Cell Batterer

y P

y Poowwerer

ed

ed

Electr

Electr

oluminescent Lam

oluminescent Lampp

Dr

Driviv

er/In

er/Invverertterer

◆ Audio/TV remote control units

◆ Pagers/Cellular phones

◆ PDAs

◆ Clocks and radios

◆ Portable GPS receivers

◆ LCD modules

◆ Toys

◆ Wide operating voltage range - from 0.9V to 2.5V

◆ Simple design requires few passive components

◆ 180V peak-to-peak typical AC output voltage

◆ Adjustable output frequency controls lamp

color and power consumption

◆ Adjustable converter frequency minimizes
circuit power consumption

◆ Disable mode extends battery life

◆ Disable current 1µA typical

◆ Compact MicroSO package option

Key Features

Applications

Block Diagram

–

+

527_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

IMP527

Bridge
Output

Driver

Q

Q

Q

V

REF

Lamp Drive

Oscillator

C

GND

5

R

EL-OSC

8

Q

The IMP527 is an Electroluminescent (EL) lamp driver designed for
systems that must operate down to 1 volt and below. The input supply
voltage range is 0.9V to 2.5V. Typical output lamp drive voltage is 180V.
All four EL lamp-driving functions are on-chip. These are the switch­mode power supply, its high-frequency oscillator, the high-voltage
H-bridge lamp driver and its low-frequency oscillator. EL lamps of up to
6nF capacitance can be driven to high brightness.

The circuit requires few external components; one inductor, one diode,
one capacitor and two resistors. The resistors set the frequency for the
two oscillators.

A disable mode puts the chip into a low current-drain state. When dis­abled, quiescent current drops to 1µA typical with a V

DD

of 1.5V. The chip

can be disabled by connecting R

SW

, the oscillator frequency setting resis­tor, to ground. A disable pad (active low), accessible only on the die, can
also be used to disable the driver.

An internal circuit shuts down the switching regulator when the lamp
drive voltage exceeds 180V peak-to-peak. This conserves power and
extends battery life.

The IMP527 is available in MicroSO and SO-8 packages and in die form.

IMP52

IMP5277

2 408-432-9100/www.impweb.com © 2000 IMP, Inc.



Parameter Symbol Conditions Min Typ Max Units

ON-resistance of MOS Switch R

DS(ON)

I = 50mA 15 Ω

Operating Voltage 0.9 2.5 V
Output Voltage at C

S

V

CS

VDD= 1.5V, See Figure 1, Table 1 80 90 V

Output Voltage at C

S

V

CS

VDD= 0.9V, See Figure 1, Table 2 50 V

Output Voltage Peak-to-Peak VA-V

B

V

DD

= 1.5V, See Figure 1 180 V

P-P

Quiescent VDDSupply Current, Disabled I

QDIS

Disable = HIGH 70 nA

(Disable pin available on die only)
Quiescent V

DD

Supply Current, Disabled I

QDIS

R

SW-OSC

= GND 1.0 2.0 µA

VDD= 1.5V

Input Current at VDDPin I

DD

VDD= 0.9V to 1.5V 1.5 mA

Input Current: IDDPlus Inductor Current I

IN

VDD= 1.5V, See Figure 1, Table 1 26 32 mA

V

A-B

Output Drive Frequency f

EL

VDD= 1.5V, See Figure 1, Table 1 500 Hz

Boost Converter Switching Frequency f

SW

VDD= 1.5V, See Figure 1, Table 1 26 kHz

Switching Duty Cycle D

SW

VDD= 1.5V, See Figure 1 87.5 %

Disable Input LOW Voltage V

DISL

GND 0.2 V

(Disable pin available on die only)
Disable Input HIGH Voltage V

DISH

VDD-0.5V V

DD

V

(Disable pin available on die only)

Ordering Information

Pin Configuration

4L

X

3C

S

2R

SW-OSC

1V

DD

5 GND

6V

B

7V

A

8R

EL-OSC

527_02.eps

IMP527

SO/MicroSO

Part Number Input Voltage Regulated Output Voltage Temperature Range Pins-Package

IMP527EMA 0.9V to 2.5V YES – 40°C to +85°C 8-MicroSO

IMP527ESA 0.9V to 2.5V YES – 40°C to +85°C 8-SO

IMP527/D* 0.9V to 2.5V YES 25°C Dice

IMP527/D1** 0.9V to 2.5V YES 25°C Dice

Absolute Maximum Ratings

Supply Voltage, VDD, V

RSW-OSC

and V

REL-OSC

. . – 0.5V to +3.5V

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

Power Dissipation (SO package) . . . . . . . . . . . . 400mW

Power Dissipation (MicroSO package) . . . . . . . 300mW

Unless otherwise noted, V

DD

= 1.5V, RSW= 1MΩ, REL= 1MΩ, 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.

Electrical Characteristics

* Disable pad not active

** Disable pad active

IMP52

IMP5277

© 2000 IMP, Inc.

Electroluminescent Lamp Driver

3

Typical Characteristics

Frequency (Hz)

REL (MΩ)

EL Lamp Drive Frequency

527_08.eps

VDD= 1.5V

TA= 25°C

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

0

400

800

1200

1600

2000

2400

Frequency (kHz)

RSW (MΩ)

527_10.eps

0 0.5 1.0 1.5 2.0 2.5 3.0

0

25

50

75

100

125

150

Boost Converter

Switching Frequency

VDD= 1.5V

TA= 25°C

Period (ms)

REL (MΩ)

527_07.eps

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

0

1

2

3

4

5

6

7

8

EL Lamp Drive Period

VDD= 1.5V

TA= 25°C

Period (ms)

RSW (MΩ)

527_09.eps

0 0.5 1.0 1.5 2.0 2.5 3.0

0

25

50

75

100

Boost Converter

Switching Period

VDD= 1.5V

TA= 25°C