ANALOG DEVICES ADM8839 Service Manual
Charge Pump Regulator
www.BDTIC.com/ADI
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 μA)
Shutdown function
Option to use external LDO
APPLICATIONS
Hand-held instruments
TFT LCD panels
Cellular phones
LDO_ON/OFF
SHDN
for Color TFT Panels
ADM8839
FUNCTIONAL BLOCK DIAGRAM
C5, 2.2µF
V
ADM8839
OSCILLATOR
CONTROL
LOGIC
TIMING
GENERATOR
SHUTDOWN
CONTROL
CC
DISCHARGE
GND
Figure 1.
VOLTAGE
DOUBLER
LDO
VOLTAGE
REGULATOR
DOUBLE
VOLTAGE
TRIPLER
TRIPLE
VOLTAGE
INVERTER
C1+
C1–
VOUT
LDO_IN
+5VOUT
+5VIN
C2+
C2–
C3+
C3–
+15VOUT
C4+
C4–
–15VOUT
C1, 2.2µF
C6, 2.2µF
C7, 2.2µF
C2, 0.22µF
C3, 0.22µF
C8, 0.22µF
C4, 0.22µF
C9, 0.22µF
+5V
+15V
–15V
03075-001
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.
The ADM8839 has a power save shutdown feature. The 5 V
o
utput 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
mini
mal power consumption. The part is packaged in a 20-lead
LFCSP (lead frame chip scale package).
Rev. C
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Anal og Devices for its use, nor for any infringements of patents or ot her
rights of third parties that may result from its use. Specifications subject to change without notice. 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 owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700 www.analog.com
Fax: 781.461.3113 ©2006 Analog Devices, Inc. All rights reserved.
ADM8839
www.BDTIC.com/ADI
TABLE OF CONTENTS
Features.............................................................................................. 1
ESD Caution...................................................................................4
Applications....................................................................................... 1
Functional Block Diagram .............................................................. 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Timing Specifications .................................................................. 3
Absolute Maximum Ratings............................................................ 4
Thermal Characteristics .............................................................. 4
REVISION HISTORY
7/06—Rev. B to Rev. C
Updated Format..................................................................Universal
Changes to Table 1............................................................................ 3
Changes to Table 5............................................................................ 5
Changes to Ordering Guide.......................................................... 10
Updated Outline Dimension......................................................... 10
Pin Configuration and Function Descriptions..............................5
Typical Performance Characteristics..............................................6
Theory of Operation .........................................................................8
Power Sequencing.........................................................................8
Transient Response .......................................................................8
Boosting the Current Drive of the ±15 V Supply .....................8
Outline Dimensions....................................................................... 10
Ordering Guide .......................................................................... 10
7/05—Rev. A to Rev. B
U
pdated Ordering Guide .................................................................3
2/03—Rev. 0 to Rev. A
C
hanged Specifications.....................................................................2
Updated Outline Dimensions..........................................................8
Rev. C | Page 2 of 12
ADM8839
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SPECIFICATIONS
VCC = 3 V (+40%/−10%); TA = −40°C to +85°C; C1, C5, C6, C7 = 2.2 μF; C2, C3, C4, C8, C9 = 0.22 μF; unless otherwise noted.
Table 1.
Parameter Test Conditions Min Typ Max Unit
INPUT VOLTAGE, VCC 2.7 4.2 V
SUPPLY CURRENT, ICC Unloaded 250 500 μA
Shutdown mode, TA = 25°C 5 μA
+5 V OUTPUT
Output Voltage IL = 10 μA to 20 mA 4.9 5.0 5.1 V
Output Current 5 20 mA
Output Ripple 8 mA load 10 mV p-p
Transient Response IL stepped from 10 μA to 8 mA 5 μs
+15 V OUTPUT
Output Voltage IL = 1 μA to 150 μA 14.0 15.0 16.0 V
Output Current 1 150 μA
Output Ripple IL = 100 μA 50 mV p-p
−15 V OUTPUT
Output Voltage IL = −1 μA to −150 μA −16.0 −15.0 −14.0 V
Output Current −150 −1 μA
Output Ripple IL = −100 μA 50 mV p-p
POWER EFFICIENCY R5 V
CHARGE PUMP FREQUENCY 60 100 140 kHz
CONTROL PINS, SHDN
Input Voltage, V
SHDN
Digital Input Current ±1 μA
Digital Input Capacitance1 10 pF
LDO_ON/OFF
Input Voltage Low = External LDO 0.3 × VCC V
High = Internal LDO 0.7 × VCC V
Digital Input Current ±1 μA
Digital Input Capacitance1 10 pF
1
Guaranteed by design. Not 100% production tested.
load = 5 mA, ±15 V load = ±150 μA, VCC = 3.0 V 82 %
OUT
low = shutdown mode
SHDN
high = normal mode
SHDN
0.3 × V
0.7 × V
V
CC
V
CC
TIMING SPECIFICATIONS
VCC = 3 V, TA = 25°C; C1, C5, C6, C7 = 2.2 μF; C2, C3, C4, C8, C9 = 0.22 μF.
Table 2.
Parameter Test Conditions/Comments Min Typ Max Unit
POWER-UP SEQUENCE
+5 V Rise Time, t
+15 V Rise Time, t
−15 V Fall Time, t
Delay Between −15 V Fall and +15 V, t
10% to 90%, see Figure 14 250 μs
R5V
10% to 90%, see Figure 14 3 ms
R15V
90% to 10%, see Figure 14 3 ms
FM15V
See Figure 14 600 μs
DELAY
POWER-DOWN SEQUENCE
+5 V Fall Time, t
+15 V Fall Time, t
−15 V Rise Time, t
90% to 10%, see Figure 14 35 ms
F5V
90% to 10%, see Figure 14 10 ms
F15V
10% to 90%, see Figure 14 20 ms
RM15V
Rev. C | Page 3 of 12
ADM8839
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ABSOLUTE MAXIMUM RATINGS
TA = 25°C, unless otherwise noted.
Table 3.
Parameter Rating
Supply Voltage −0.3 V to +6.0 V
Input Voltage on Digital Inputs −0.3 V to +6.0 V
Output Short-Circuit Duration to GND 10 sec
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
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
ma
y cause permanent 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.
THERMAL CHARACTERISTICS
θJA is specified for the worst-case conditions, that is, a device
soldered in a circuit board for surface-mount packages.
Table 4. Thermal Resistance
Package Type θJA Unit
20-Lead LFCSP_VQ 31°C °C/W
ESD 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 this product 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. C | Page 4 of 12
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