LXM1640.pdf

Not Recommended for New Design
LXM1640-01
D I R E C T D R I V E Q U A D L A M P CCFL I N V E R T E R M O D U L E
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Production Data Sheet
N N O VA T I O N
DESCRIPTION
erating at near normal brightness in the
event that a lamp fails. This allows the
display to remain "on-line" until lamp replacement is convenient.
Quad Module Uses Standard Power
Supply. The LXM1640 module uses a standard 12V input supply. It also ensures
nominal power consumption with 4 lamps
requiring only 16 watts. Lamp current is
fully regulated with respect to input voltage and output impedance variations.
Dimming Features. The LXM1640 modules are equipped with a dimming input
that permits brightness control from an
external potentiometer or DC voltage. In
addition, the sleep input reduces module
power to a few microwatts in shut down
mode. All LXM1640 modules feature both
output open and short-circuit protection.
The Most Efficient and Cost-effective
Backlight Inverter for Desktop/Industrial Applications. Linfinity's proprietary
Direct Drive architecture is the highest efficiency, small form factor solution for all
multiple lamp applications. The LXM1640
is fully customizable (electronically and mechanically) to specific customer requirements.
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Drive Four Lamps With One Module
Small, Compact Size
High Efficiency
Multiple Output Connectors Provide Easy
LCD Connections
Low EMI And Noise
Low Power Sleep Mode
Output Short And Open Circuit Protection
3:1 Dimming Control
Adjustable Lamp Current Up To 6.0mA Per
Lamp
Long Lamp Life With Soft-Start And
Accurate Lamp Current Regulation
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The Quad Output Module Ideal for
Desktop and Industrial Applications.
The LXM1640 Direct DriveTM Cold Cathode
Fluorescent Lamp (CCFL) Inverter is a single
module designed to drive four lamps and
is targeted for use with desktop Liquid Crystal Display (LCD) and industrial LCD panels typically ranging in size from 14-inches
to 21-inches. This four output inverter is
the ideal solution to power virtually any
four lamp application.
Direct Drive Technology. The module design is based on a new Direct Drive
topology, which provides a number of cost
and per for mance advantages. The
LXM1640-01 Direct Drive inverters eliminate
the classic resonant inductor and capacitors, thus reducing cost and allowing a substantial reduction in module size.
Fixed-Frequency Operation. Other
benefits of this new topology are fixed-frequency operation and secondary-side
strike-voltage regulation. Strike-voltage
regulation minimizes corona discharge in
the output transformer and related circuitry,
providing longer life and higher reliability.
Fail-safe Feature For Multiple Lamp
Applications. Our multi-output inverters
are designed to keep your application op-
K E Y F E AT U R E S
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A P P L I C AT I O N S
■ Desktop LCD Monitors And Panels
■ Industrial LCD Panels
■ Hi-Brite Displays
BENEFITS
■ Cool Operation
■ Smooth, Easy-To-Use Brightness Control
■ Single 12 Volt Supply
IMPORTANT: For the most current data, consult LinFinity's web site: http://www.linfinity.com.
PRODUCT HIGHLIGHT
LXM1640 "U N I V E R S A L " M O D U L E C O N N E C T I O N O P T I O N S
CN7
CN3
CN6
CN1
CN2
LXM1640-01
CN5
CCFL Lamps
CN4
CN7
CN3
Dual Connector Configuration
CN5
CCFL Lamps
CN6
CN1
LXM1640-01
O
CN2
CN4
Quad Connector Configuration
Desktop Display
Desktop Display
M O D U L E O R D E R I N F O R M AT I O N
LXM1640-01
Protected By U.S. Patents: 5,923,129; 5,930,121; Patents Pending
Copyright © 1998
Rev. 1.0
LINFINITY MICROELECTRONICS INC.
11861 W ESTERN A VENUE, G ARDEN G ROVE, CA. 92841, 714-898-8121, F AX: 714-893-2570
PRODUCT DATABOOK 1996/1997
LXM1640-01
D I R E C T D R I V E Q U A D L A M P CCFL I N V E R T E R M O D U L E
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A B S O L U T E M A X I M U M R AT I N G S
(Note 1)
Input Supply Voltage (VIN)....................................................................................................................................................... -0.3V to 16V
Output Voltage, no load .............................................................................................................................. Internally Limited to 1800VRMS
Output Current (per Lamp) ........................................................................................................................ 10.0mARMS (Internally Limited)
Output Power (per Lamp) .................................................................................................................................................................... 6.0W
Input Signal Voltage, (SLEEP and BRITE Inputs) ..................................................................................................................... -0.3V to VIN
Ambient Operating Temperature, zero airflow ........................................................................................................................ 0°C to 40°C
Storage Temperature Range ................................................................................................................................................... -40°C to 85°C
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Note 1. Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground. Currents are positive into, negative
out of the specified terminal.
R E C O M M E N D E D O P E R AT I N G C O N D I T I O N S (R.C.)
This module has been designed to operate over a wide range of input and output conditions. However, best efficiency and performance
will be obtained if the module is operated under the condition listed in the 'R.C.' column. Min. and Max. columns indicate values beyond
which the inverter, although operational, will not function optimally.
Parameter
Symbol
Input Supply Voltage Range (Functional)
Output Power (per Lamp)
Brightness Control Input Voltage Range
Lamp Operating Voltage
Lamp Current (Full Brightness - per Lamp)
Operating Ambient Temperature Range
Recommended Operating Conditions
Min.
R.C.
Max.
VIN
PO
10.8
VBRT ADJ
VLAMP
IOLAMP
TA
0.0
300
12
4
Units
13.2
5
5.0
800
675
6.0
0
V
W
V
VRMS
mA RMS
°C
40
ELECTRICAL CHARACTERISTICS
Unless otherwise specified, these specifications apply over the recommended operating conditions and 25°C ambient temperature for the LXM1640.
Parameter
Symbol
Test Conditions
LXM1640-01
Min. Typ.
Max.
Units
Output Pin Characteristics
Full Bright Lamp Current (per Lamp)
Minimum Lamp Current (per Lamp)
(Note 2)
Lamp Start Voltage
Operating Frequency
IL (MAX)
I L (MIN)
VBRT ADJ = 5.0VDC, SLEEP = HIGH, VIN = 12VDC
VBRT ADJ = 0VDC, SLEEP = HIGH, V IN = 12V DC
5.4
V LS
fO
0°C < TA < 40°C, VIN ≥ 10.8V DC
VBRT ADJ = 5.0VDC, SLEEP = HIGH, VIN = 12VDC
1500
52
IBRT
VC
VC
VBRT ADJ = 0VDC
IO (LAMP) = 100%
IO (LAMP) = Minimum
6.0
0.5
57
6.6
mA RMS
mA RMS
1800
62
VRMS
KHz
33
µADC
VDC
VDC
VDC
VDC
µADC
µADC
BRITE Input
O
Input Current
Input Voltage for Max. Lamp Current
Input Voltage for Min. Lamp Current
27
30
5.0
0
SLEEP Input
RUN Mode
SLEEP Mode
Input Current
VSLEEP (HI)
VSLEEP (LO)
ISLEEP
SLEEP = 5.0V
2.2
-0.3
90
110
VIN
0.8
150
0
10
500
Power Characteristics
Sleep Current
IIN (MIN)
VIN = 12VDC , SLEEP = 0VDC
Note 2. Minimum lamp current required to maintain even light output may vary with display panel.
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Copyright © 1998
Rev. 1.0 1/05
PRODUCT DATABOOK 1996/1997
LXM1640-01
D I R E C T D R I V E Q U A D L A M P CCFL I N V E R T E R M O D U L E
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FUNCTIONAL PIN DESCRIPTION
Pin
Description
CN1-1
CN1-2
VIN
Input Power Supply. (10.8V ≤ VIN ≤ 13.2V)
CN1-3
CN1-4
GND
Power Supply Return.
CN1-5
SLEEP
ON/OFF Control. (2.2V < SLEEP < VIN = ON, -0.3V < SLEEP < 0.8V = OFF)
CN1-6
CN1-7
CN1-8
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Conn.
CN1
BRITE
Brightness Control (-0.3V to 5.0VDC ).
N.C.
No Connect.
N.C.
No Connect.
5.0VDC gives maximum lamp current.
CN2 and CN3: Refer to Figure 1
PHYSICAL DIMENSIONS
LXM1640-01
All dimensions are in inches (mm)
6.89 (175)
0.016
(4)
6.73 (171)
0.016 (4)
Ø 0.118 (3.0) Mtg. Hole, 2 Places
CN3
CN2
0.94
(24)
CN7
CN6
CN1
0.33 (8.5)
CN5
CN4
0.32 (8.25)
0.06 (1.52)
O
0.46 (11.8)
Copyright © 1998
Rev. 1.0 1/05
3
PRODUCT DATABOOK 1996/1997
LXM1640-01
D I R E C T D R I V E Q U A D L A M P CCFL I N V E R T E R M O D U L E
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R E L I M I N A R Y
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A T A
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H E E T
C O N N E C T O R S C H E M AT I C
CN4
3
2
CN5
1
2
CN1
1
CN6
8
N.C.
VHI1
1
VHI2
Inverter
Output 2
VHI3
Inverter
Output 3
CN7
1
2
1
N.C.
VHI4
Inverter
Output 4
3
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Inverter
Output 1
2
1
2
3
4
CN2
1
2
3
4
CN3
FIGURE 1 — LXM1640-01 Connector Schematic
Connectors:
CN1 = MOLEX 53261-0890
Mates With:
Pins: 50079-8100*, Housing: 51021-0800
CN2, CN3 = JST SM04(4.0)B-BHS-1-TB
JST BHR-04VS-1
CN4, CN7 = JST SM03(4.0)B-BHS-1-TB
JST BHR-03VS-1
CN5, CN6 = JST SM02(8.0)B-BHS-1-TB
JST BHR-03VS-1
* Loose (-8000, Chain) Recommended #26 AWG wiring
Connection Rules
1. Always install four (4) lamps. Operating with out all lamps may overdrive lamp current at maximum brightness settings.
2. Verify lamp wiring before connecting lamps to the inverter module. Connecting more than one lamp to one of the four inverter output
circuits will result in reduced brightness. The LXM1640-01 module connectors are wired per industry standard. The lamp hot wires
(high voltage wires) are always on pin 1 or 2, and the cold wire (low voltage wire) is always on pin 3 or 4.
F A I L S A F E F E A T U R E F O R M U L T I P L E L A M P O P E R AT I O N S
O
Our multi-output inverters are designed to keep your application
operating at near normal brightness in the event that a lamp fails.
This allows the display to remain "on-line" until lamp replacement
is convenient.
Linfinity "pairs" the lamps so that if one lamp in the pair breaks,
most of its current is added to the good lamp. CCFLs will respond
with more brightness for a period of time. Operating time in this
mode will be a function of the lamps age but should be typically
in the order of hundreds of hours.
This operating characteristic can provide adequate display
performance for a limited, but useful period of time. Shortening
of the lamp life in this mode is typically not a concern as it is
recommended that all lamps in a display be replaced at the same
time.
Lamps
IS
FIGURE 2 — Quad Output Stage
4
Copyright © 1998
Rev. 1.0 1/05
PRODUCT DATABOOK 1996/1997
LXM1640-01
D I R E C T D R I V E Q U A D L A M P CCFL I N V E R T E R M O D U L E
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DIRECT DRIVE OUTPUT ARCHITECTURE
If no current flows in the CCFL return path because of an
unstruck or failed lamp, the inverter applies full strike voltage
potential. The output voltage feedback loop (VSNS) takes control
and regulates output voltage to 1650VRMS. This insures lamps will
ignite under worst case temperature and aging conditions.
Because output voltage is actively regulated, it will never exceed
component and panel insulation ratings. This prevents destructive
corona discharge to insure long term reliability of the system.
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Direct Drive architecture includes two load feedback control loops
to provide uncompromised CCFL ignition and operation characteristics.
Lamp current is regulated in the CCFL return lead (ISNS loop) to
insure constant light output with changing lamp parameters and
power supply voltage. This also allows accurate and repeatable
brightness control. Dimming ratio with the LX1640 analog dimming
inverters is typically 6:1 when driving quad LCD lamp panels.
High Voltage
Transformer
VHI1
SLEEP
Controller
GND
LAMP 1
BRITE
Transformer
Driver
VSENSE
ISENSE
VLO
FIGURE 3 — LXM1640 Block Diagram
(Only one lamp shown)
T Y P I C A L A P P L I C AT I O N S
10.8VDC- 13.2VDC
5.0VDC
0V
SLEEP
GND
Lamp 4
5V
LXM1640-01
Lamp 3
O
BRITE
Lamp 1
≤10k
VHI4
VHI3
VHI2
VHI1
Lamp 2
VIN
VLO
FIGURE 4 — Potentiometer Brightness Control
PRELIMINARY DATA - Information contained in this document is pre-production data, and is proprietary to LinFinity. It may
not modified in any way without the express written consent of LinFinity. Product referred to herein is offered in sample form
only, and Linfinity reserves the right to change or discontinue this proposed product at any time.
Copyright © 1998
Rev. 1.0 1/05
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