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LX1691_06 Datasheet, PDF (1/2 Pages) Microsemi Corporation – Enhanced Multi-Mode CCFL Controller | |||
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LX1691
TM
®
Enhanced Multi-Mode CCFL Controller
PRODUCTION DATA SHEET
DESCRIPTION
Microsemiâs LX1691 is a cost
reduced, enhanced feature set, Direct
Drive CCFL (Cold Cathode Fluorescent
Lamp) Controller. Its architecture is
based on the very popular LX1689. By
limiting VDDP to 5.5V and using
advanced processing, die size and
package pin count is decreased while
improving dimming precision.
LX1691 based inverter modules can
be designed for virtually any CCFL
appliance from digital cameras and
PDAâs to big screen monitors and
driver viewable automotive displays.
New versatile dimming circuitry can
accept digital and analog control inputs
and provides six different dimming
modes that control both lamp current
amplitude and duty cycle, either simul-
taneously or separately. Designers can
select normal or reverse polarity
dimming and precisely program mini-
mum and maximum lamp currents with
resistors. The LX1691 fault shutdown
feature is enhanced to include regu-
lation and shutdown for over voltage
and over current conditions.
Microsemiâs proven and patented
Direct Drive architecture works with
system voltages from 3 volts to more
than 50 volts, limited only by the
external power FETâs that drive the high
voltage transformer.
The LX1691 includes the Microsemi
proven and patented strike method that
allows significant efficiency gains while
guaranteeing strong striking power at all
operating temperatures. Our method
sweeps strike frequency smoothly up to
the unloaded resonant frequency of the
lamp and high voltage transformer.
This, coupled with the LX1691âs active
high output voltage regulation, produces
just enough strike voltage without
generating unpredictable high voltage
spikes that cause arcing and component
failures. Competitive devices that
simply switch to a higher frequency for
striking do not have this âreal timeâ
control over output voltage, and require
much more attention to transformer
design.
IMPORTANT: For the most current data, consult MICROSEMIâs website: http://www.microsemi.com
Protected by U.S. Patents: 5,615,093; 5,923,129; 5,930,121; 6,198,234; Patents Pending
KEY FEATURES
 Simultaneous Amplitude And
Duty Cycle Dimming Modes
 Resistor Programmable Min and
Max Lamp Currents
 Digital Dimming Can Synch To
External Or Internal Clocks
 100 ms Power On Delay
 Open Or Shorted Lamp
Regulation & Shutdown
 âOn Chipâ Full Wave Lamp
Current & Voltage Rectifiers
 16 Pin TSSOP Package
 Very Stable Oscillator with On-
Chip Timing Capacitor
 Soft Start-Up Striking
 Enhanced Digital Dimming
Resolution
BENEFITS
 Low Component Count / Module
Cost / And Size
 High âNits/Wattâ Efficiency
 Operates Directly From a Single
Li-Ion Cell
 Industries Safest And Highest
Performing Strike Voltage
Generation (Patented)
 Tight Operating Frequency
Tolerance For Easier System
Level RFI Control
Traditional Analog
2
BRITE_IN
PRODUCT HIGHLIGHT
Lamp Current (mA)
+
External Digital
2
BRITE_IN
Lamp Current (mA)
+
+3V
0
T1
T2 DD_CLK
Internal Digital
2
BRITE_IN
+3V
0
T
DD_CLK
T = 512 / Lamp Frequency
_
T1
T2
Lamp Current (mA)
+
0
T
DD_CLK
T = 512 / DD_CLK Frequency
Direct PWM (Analog)
2
BRITE_IN
_
T
Lamp Current (mA)+
_
0
T1
T
T2 DD_CLK
_
T1
T2
Four of Six Dimming Modes
Copyright © 2003
Rev. 1.2, 8/30/2006
PACKAGE ORDER INFO
TA (°C)
-40 to +85
MIN VDDP
2.8V
MAX VDDP
5.5V
Plastic TSSOP
PW 16-PIN
RoHS compliant / Pb-free
LX1691IPW
Note: Available in Tape & Reel. Append the letters âTRâ to the part number. (i.e. LX1691IPW-TR)
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
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