AME, Inc.
AME9003
y
inar
lim
Pre
CCFL Backlight Controller
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General Description
The AME9003 is AME’ s next generation direct drive
CCFL controller. Like its cousins, the AME9001 and
AME9002, the AME9003 controller provides a cost effi-
cient means to drive single or multiple cold cathode fluo-
rescent lamps (CCFL), driving 3 external MOSFETs that,
in turn, drive a wirewound transformer that is coupled to
the CCFL.
The AME9003, like the AME9002 includes extra cir-
cuitry that allows for a special one second start up pe-
riod wherein the voltage across the CCFL is held at a
higher than normal voltage to allow older tubes (or cold
tubes) a period in which they can” warm up” . During
this one second startup period the driving frequency is
adjusted off of resonance so that the tube voltage can be
controlled. As soon as the CCFL
”
strikes” the special
start up period ends and the circuit operates in its normal
mode. However the AME9003 uses an extra capacitor to
accurately set the start up interval. In addition to that the
AME9003 features a soft start AND soft finish on each
dimming cycle edge in order to minimize any audible
vibrations during the dimming function.
The AME9003 also includes features such as, dimming
control polarity selection, undervoltage lockout and fault
detection. It is designed to work with input voltages from
7V up to 24V. When disabled the circuit goes into a zero
current mode.
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Pin Configuration
24
23
22
21
20
19
18
17
16
15
14
13
AME9003
1
2
3
4
5
6
7
8
9
10
11
12
AME9003
1. VREF
2. CE
3. SSC
4. RDELTA
5. SSC1ST
6. RT2
7. VSS
8. OVPH
9. OVPL
10.FCOMP
11.CSDET
12.BATTFB
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
OUTC
OUTAPB
OUTA
VBATT
BRPOL
VDD
CT1
FB
COMP
BRIGHT
SSV
PNP
Evaluation Board Available !!
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System Block Diagram
Controller
External
Components
CCFL Array
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Features
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Small 24 pin QSOP package
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24 pin PDIP/SOIC also available
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Drives multiple tubes
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Special 1 second start up mode
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Automatically checks for common fault
conditions
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7.0V < Vbatt < 24V
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Low component count
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Low Idd < 3.5mA
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<1uA shutdown mode
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Battery UV lockout
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Brightness polarity select
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Soft-start, soft-finish dimming
AME
9003
LIGHT
+
Resistors
+
Capacitors
N
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Applications
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Notebook computers
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LCD/TFT displays
1
AKM [ ASAHI KASEI MICROSYSTEMS ]
