QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 510
1WATT CCFL POWER SUPPLY
LTC1697
DESCRIPTION
Demonstration Circuit 510 is a 1Watt single output
CCFL inverter with internal PWM dimming and bot-
tom bulb sense feedback features. The Demo Board
consists of a LTC1697 CCFL Controller and a Royer
converter that uses bipolar transistors. The LTC1697
also features internal CCFL short circuit and over-
voltage protection. The maximum lamp current is set
by a single resistor while a 1V –2V Dimming input
allows the user to set the desired lamp current any-
where between 0 and the maximum CCFL current set
by R5.
Using the LTC1697 with the Royer topology results in
a particularly low component count design. Target
applications for this Demo Board are PDAs such as
Handheld Computers, Handheld GPSs with Map Dis-
plays, and Handheld TV\Video Monitors.
DC510 is designed to operate off a single Li-Ion cell
for a Vin range of 2.7V – 5.5V and outputs 100s of
volts at milliAmp current levels.
Design files for this circuit board are available. Call
the LTC factory.
QUICK START PROCEDURE
DC510 is easy to set up to evaluate the performance
of the LTC1697. Refer to Figure 1 for proper meas-
urement equipment setup and follow the procedure
below:
1.
Connect the LCD\CCFL across the E1 & E2 termi-
2.
Ground the LCD Casing through the DC510 GND
terminal.
3.
Apply 2.7V – 5.5V across the VIN & GND termi-
nals.
4.
Apply 1.0V – 2.0V across the VDIM & GND termi-
nals. Connect the positive CCFL wire to E2 and the
negative wire of the LCD to E1.
Warning:
There may be 100s of volts across the E1
& E2 terminals, across the capacitor C1, and on the
secondary side of the transformer T1 that can be
harmful if the user accidentally or otherwise
touches these points.
nals, measuring the CCFL current for the desired
output CCFL current.
Figure 1. Proper Measurement Equipment Setup
1
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