LT1182/LT1183/LT1184/LT1184F
CCFL/LCD Contrast
Switching Regulators
FEATURES DESCRIPTION
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Wide Input Voltage Range: 3V to 30V The LT 1182/LT1183 are dual current mode switching
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Low Quiescent Current regulators that provide the control function for Cold Cath-
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High Switching Frequency: 200kHz ode Fluorescent Lighting (CCFL) and Liquid Crystal Display
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CCFL Switch: 1.25A, LCD Switch: 625mA (LCD) Contrast. The LT1184/LT1184F provide only the
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Grounded or Floating Lamp Configurations CCFL function. The ICs include high current, high efficiency
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Open-Lamp Protection switches, an oscillator, a reference, output drive logic,
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Positive or Negative Contrast Capability control blocks and protection circuitry. The LT1182 per-
mits positive or negative voltage LCD contrast operation.
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APPLICATIONS The LT1183 permits unipolar contrast operation and pins
out an internal reference. The LT1182/LT1183 support
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Notebook and Palmtop Computers
grounded and floating lamp configurations. The LT1184F
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Portable Instruments
supports grounded and floating lamp configurations. The
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Automotive Displays
LT1184 supports only grounded lamp configurations. The
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Retail Terminals
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
90% Efficient Floating CCFL Configuration with Dual Polarity LCD Contrast
UP TO 6mA
ALUMINUM ELECTROLYTIC IS RECOMMENDED FOR C3B WITH AN
CCFL BACKLIGHT APPLICATION CIRCUITS CONTAINED IN THIS
LAMP
C2
ESR 0.5 TO PREVENT DAMAGE TO THE LT1182 HIGH-SIDE
DATA SHEET ARE COVERED BY U.S. PATENT NUMBER 5408162
27pF
SENSE RESISTOR DUE TO SURGE CURRENTS AT TURN-ON.
AND OTHER PATENTS PENDING
3kV
10 6
C1 MUST BE A LOW LOSS CAPACITOR, C1 = WIMA MKP-20
L1
Q1, Q2 = ZETEX ZTX849 OR ROHM 2SC5001
L1 = COILTRONICS CTX210605
3
2 1 4 5
BAT
L2 = COILTRONICS CTX100-4
+ 8V TO 28V
C3B
+
C3A
2.2F
L3 = COILTRONICS CTX02-12403
C5
2.2F
EITHER NEGCON OR POSCON
R2
35V
1000pF 35V MUST BE GROUNDED.
220k
*DO NOT SUBSTITUTE COMPONENTS
GROUNDING NEGCON GIVES
R1
COILTRONICS (407) 241-7876
VARIABLE POSITIVE CONTRAST
C1*
750
FROM 10V TO 30V.
0.068F
0A TO 45A ICCFL
+
C12
GROUNDING POSCON GIVES
CURRENT GIVES
2.2F
VARIABLE NEGATIVE CONTRAST
0mA TO 6mA
R3
35V
FROM 10V TO 30V.
100k
BULB CURRENT.
Q2* Q1*
THIS IS EQUAL TO
POSCON
D5
0% TO 90% DUTY
D3
L3
BAT85
CYCLE FOR THE
1N5934A
6
C11
+
PWM SIGNAL. L2
4
D1
24V
22F
100H
1N5818
35V
R4
D2
1
16
2
9
CCFL
46.4k
CCFL V
1N914
SW
PGND
R5, 43.2k, 1%
V (PWM)
1% NEGCON
2
15
0V TO 5V
I
BULB
N = 1:2
CCFL
D4
1kHz PWM
+
1N914
C6
3
14
DIO
BAT
2.2F
C7, 1F
R12
LT1182
4
13
V
IN
20k
CCFL V
ROYER
C
3V
+
C4
5
12
R13
AGND
V
2.2F
IN
8.45k
1%
6
11
SHUTDOWN
SHDN
FBP
C8, 0.68F C9, 0.01F
R14
7
10
C10
1.21k
LCD V FBN
C
0.01F
1%
R7, 10K
8
9
LCD
LCD V
SW
PGND
R9, 4.99k, 1% R10, 10k, 1% R11, 20k, 1%
5V
1182/3 TA01
1
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ULT1182/LT1183/LT1184/LT1184F
DESCRIPTION
LT1184/LT1184F pin out the reference for simplified pro-
current. An active low shutdown pin typically reduces total
gramming of lamp current.
supply current to 35A for standby operation. A 200kHz
switching frequency minimizes the size of required mag-
The LT1182/LT1183/LT1184/LT1184F operate with input
netic components. The use of current mode switching
supply voltages from 3V to 30V. The ICs also have a
techniques with cycle-by-cycle limiting gives high reliabil-
battery supply voltage pin that operates from 4.5V to 30V.
ity and simple loop frequency compensation. The LT1182/
The LT1182/LT1183 draw 9mA typical quiescent current
LT1183/LT1184/LT1184F are all available in 16-pin nar-
while the LT1184/LT1184F draw 6mA typical quiescent
row SO packages.
ABSOLUTE MAXIMUM RATINGS
LT1183/LT1184/1184F: REF Pin Source Current .... 1mA
V , BAT, Royer, Bulb .............................................. 30V
IN
Junction Temperature (Note 1)............................ 100C
CCFL V , LCD V ............................................... 60V
SW SW
Operating Ambient Temperature Range ..... 0C to 100C
Shutdown ................................................................. 6V
Storage Temperature Range ................. 65C to 150C
I Input Current .............................................. 10mA
CCFL
Lead Temperature (Soldering, 10 sec).................. 300C
DIO Input Current (Peak, < 100ms) .................... 100mA
LT1182: FBP, FBN, LT1183: FB Pin Current......... 2mA
PACKAGE/ORDER INFORMATION
TOP VIEW TOP VIEW
ORDER PART ORDER PART
CCFL V
CCFL V
CCFL PGND
1
16
CCFL PGND
1
16
SW SW
NUMBER NUMBER
BULB
BULB
I
2
15
I
2
15
CCFL CCFL
BAT
BAT
DIO
3
14
DIO
3
14
LT1182CS LT1183CS
ROYER
ROYER
CCFL V
4
13
CCFL V
4
13
C C
V
V
AGND
5
12
AGND
5
12
IN IN
FBP
REF
SHUTDOWN
6
11
SHUTDOWN
6
11
FBN
FB
LCD V
7
10
LCD V
7
10
C C
LCD V LCD V
LCD PGND 8 9 LCD PGND 8 9
SW SW
S PACKAGE
S PACKAGE
16-LEAD PLASTIC SO 16-LEAD PLASTIC SO
T = 100C, = 100C/W
T = 100C, = 100C/W
JMAX JA
JMAX JA
TOP VIEW TOP VIEW
ORDER PART
ORDER PART
CCFL PGND
1
16
CCFL V
CCFL PGND
CCFL V
NUMBER
SW NUMBER 1
16
SW
I
2
15
BULB
I
BULB
2
15
CCFL CCFL
DIO
3
14
BAT
DIO
BAT
3
14
LT1184FCS
LT1184CS
CCFL V
4
13
NC
CCFL V
ROYER
4
13
C C
AGND
5
12
V
AGND
V
IN 5
12
IN
SHUTDOWN
6
11
REF
SHUTDOWN
REF
6
11
NC
7
10
NC
NC
NC
7
10
NC 8 9 NC NC NC
8 9
S PACKAGE
S PACKAGE
16-LEAD PLASTIC SO 16-LEAD PLASTIC SO
T = 100C, = 100C/W T = 100C, = 100C/W
JMAX JA JMAX JA
Consult factory for Industrial and Military grade parts
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