AME9002 Datasheet, PDF (1/37 Pages) Asahi Kasei Microsystems – CCFL Backlight Controller

AME, Inc.
AME9002
Preliminary
CCFL Backlight Controller
n General Description
The AME9002 is AME’s next generation direct drive
CCFL controller. Like its cousin, the AME9001, the
AME9002 controller provides a cost efficient means to
drive single or multiple cold cathode fluorescent lamps
(CCFL), driving 3 external MOSFETs that, in turn, drive a
wirewound transformer that is coupled to the CCFL.
However the AME9002 includes extra circuitry that al-
lows for a special one second start up period 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 reso-
nance 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.
The AME9002 includes features such as soft start, duty
cycle dimming control, dimming control polarity selec-
tion, undervoltage lockout and fault detection. It is de-
signed to work with input voltages from 7V up to 24V.
When disabled the circuit goes into a zero current mode.
n Pin Configuration
24 23 22 21 20 19 18 17 16 15 14 13
AME9002
1 2 3 4 5 6 7 8 9 10 11 12
AME9002
1. VREF
2. CE
3. SSC
4. RDELTA
5. FAULTB
6. RT2
7. VSS
8. OVPH
9. OVPL
10.FCOMP
11.CSDET
12.BATTFB
13. OUTC
14. OUTAPB
15. OUTA
16. VBATT
17. BRPOL
18. VDD
19. CT1
20. FB
21. COMP
22. BRIGHT
23. SSV
24. PNP
n System Block Diagram
n Features
l Small package: 24 pins for QSOP/ SOIC/
PDIP packages
l Drives multiple tubes
l Special 1 second start up mode
l Automatically checks for common fault
conditions
l 7.0V < Vbatt < 24V
l Low component count
l Low Idd < 3.5mA
l <1uA shutdown mode
l Battery UV lockout
l Brightness polarity select
Controller
External
Components
CCFL Array
AME
9002
+
Resistors
+
Capacitors
N
n Applications
l Notebook computers
l LCD/TFT displays
LIGHT
1