Analog Devices ADM8839 a Datasheet

Charge Pump Regulator

for Color TFT Panels

ADM8839

FEATURES
3 Voltages (+5 V, +15 V, –15 V) from

a Single 3 V Supply

Power Efficiency Optimized for Use

with TFT in Mobile Phones
Low Quiescent Current
Low Shutdown Current (<5 A)
Shutdown Function
Option to Use External LDO

APPLICATIONS
Hand-held Instruments
TFT LCD Panels
Cellular Phones

LDO_ON/OFF

SHDN

FUNCTIONAL BLOCK DIAGRAM

C5, 2.2␮F

CC

VOLTAGE

DOUBLER

LDO

VOLTAGE

REGULATOR

DOUBLE

VOLTAGE

TRIPLER

TRIPLE

VOLTAGE

INVERTER

GND

C1+

C1–

VOUT
LDO_IN

+5VOUT
+5VIN

C2+

C2–

C3+

C3–

+15VOUT

C4+

C4–

–15VOUT

ADM8839

OSCILLATOR

CONTROL

LOGIC

TIMING

GENERATOR

SHUTDOWN

CONTROL

V

DISCHARGE

C1, 2.2␮F

C6, 2.2␮F

+5V

C7, 2.2␮F

C2, 0.22␮F

C3, 0.22␮F

+15V

C8, 0.22␮F

C4, 0.22␮F

–15V

C9, 0.22␮F

GENERAL DESCRIPTION

The ADM8839 is a charge pump regulator used for color thin film
transistor (TFT) liquid crystal displays (LCDs). Using charge
pump technology, the device can be used to generate three
voltages (+5 V ± 2%, +15 V, –15 V) from a single 3 V supply.
These voltages are then used to provide supplies for the LCD
controller (5 V) and the gate drives for the transistors in the
panel (+15 V and –15 V). Only a few external capacitors are
needed for the charge pumps. An efficient low dropout (LDO)
voltage regulator ensures that the power efficiency is high and
provides a low ripple 5 V output. This LDO can be shut down
and an external LDO can be used to regulate the 5 V doubler
output and drive the input to the charge pump section that
generates the +15 V and –15 V outputs, if required by the user.

REV. A

Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective companies.

The ADM8839 has a power save shutdown feature. The 5 V
output consumes the most power, so power efficiency is also
maximized on this output with an oscillator enabling scheme
(Green Idle™). This effectively senses the load current that is
flowing and turns on the charge pump only when charge needs
to be delivered to the 5 V pump doubler output.

The ADM8839 is fabricated using CMOS technology for minimal
power consumption. The part is packaged in a 20-lead LFCSP
(lead frame chip scale package).

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] © 2003 Analog Devices, Inc. All rights reserved.

(VCC = 3 V – 10%, 40%; TA = –40C to +85C; C1, C5, C6, C7 = 2.2 F; C2, C3,

ADM8839–SPECIFICATIONS

C4, C8, C9 = 0.22 F; unless otherwise noted.)

Parameter Test Conditions Min Typ Max Unit

INPUT VOLTAGE, V

CC

SUPPLY CURRENT, I

CC

Unloaded 250 500 ␮A

2.7 4.2 V

Shutdown Mode, TA = 25°C 5 ␮A

+5 V OUTPUT

Output Voltage IL = 10 ␮A to 8 mA 4.9 5.0 5.1 V
Output Current 58 mA
Output Ripple 8 mA Load 10 mV p-p
Transient Response IL Stepped from 10 ␮A to 8 mA 5 ␮s

+15 V OUTPUT

Output Voltage I

= 1 ␮A to 150 ␮A 14.0 15.0 16.0 V

L

Output Current 1 150 ␮A
Output Ripple IL = 100 ␮A50mV p-p

–15 V OUTPUT

Output Voltage I

= –1 ␮A to –150 ␮A –16.0 –15.0 –14.0 V

L

Output Current –150 –1 ␮A
Output Ripple IL = –100 ␮A50mV p-p

POWER EFFICIENCY R5V

Load = 5 mA, 82 %

OUT

⫾15 V Load = ⫾150 ␮A,
V

= 3.0 V

CC

CHARGE PUMP FREQUENCY 60 100 140 kHz
CONTROL PINS, SHDN

Input Voltage, V

SHDN

SHDN Low = Shutdown Mode 0.3 ⫻ V
SHDN High = Normal Mode 0.7 ⫻ V

CC

CC

V
V

Digital Input Current ⫾1 ␮A
Digital Input Capacitance* 10 pF

LDO_ON/OFF

Input Voltage Low = External LDO 0.3 ⫻ V

High = Internal LDO 0.7 ⫻ V

CC

CC

V
V

Digital Input Current ⫾1 ␮A
Digital Input Capacitance* 10 pF

*Guaranteed by design. Not 100% production tested.

Specifications are target values and are subject to change without notice.

TIMING SPECIFICATIONS

(VCC = 3 V, TA = 25C; C1, C5, C6, C7 = 2.2 F; C2, C3, C4, C8, C9 = 0.22 F.)

Parameter Test Conditions/Comments Min Typ Max Unit

POWER-UP SEQUENCE

+5 V Rise Time, t

R5V

+15 V Rise Time, t
–15 V Fall Time, t

FM15V

R15V

10% to 90%, Figure 1 250 ␮s
10% to 90%, Figure 1 3 ms
90% to 10%, Figure 1 3 ms

Delay between –15 V Fall

and +15 V, t

DELAY

Figure 1 600 ␮s

POWER-DOWN SEQUENCE

+5 V Fall Time, t
+15 V Fall Time, t
–15 V Rise Time, t

Specifications are subject to change without notice.

F5V

F15V

RM15V

90% to 10%, Figure 1 35 ms
90% to 10%, Figure 1 10 ms
10% to 90%, Figure 1 20 ms

REV. A–2–

ADM8839

ABSOLUTE MAXIMUM RATINGS*

(TA = 25°C, unless otherwise noted.)

Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +6.0 V

THERMAL CHARACTERISTICS

20-Lead LFCSP Package:

= 31°C/W

␪

JA

Input Voltage on Digital Inputs . . . . . . . . . . . –0.3 V to +6.0 V

Output Short-Circuit Duration to GND . . . . . . . . . . . . .10 sec

ORDERING GUIDE

Output Voltage

+5 V Output . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 V to 7.0 V

–15 V Output . . . . . . . . . . . . . . . . . . . . . . . . –17 V to +0.3 V

+15 V Output . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +17 V

Model Temperature Range Package Option

ADM8839ACP –40°C to +85°C CP-20

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

Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 mW

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

ESD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Class I

*Stresses above those listed under Absolute Maximum Ratings may cause perma-

nent damage to the device. This is a stress rating only; functional operation of the
device at these or any other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.

CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection. Although the
ADM8839 features proprietary ESD protection circuitry, permanent damage may occur on devices
subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended
to avoid performance degradation or loss of functionality.

REV. A

–3–