.38 Watt LCD Single Series DC/DC Converters
Features
!
3 or 5 Volt Inputs
!
Positive or Negative LCD Bias Output
!
Simple 4 Terminal Operation
!
Low Cost
!
Small Sealed SIP Package
!
5 Year Warranty
Description
Selection Chart
Input Range
VDC
The LCD Series of DC/DC converters provides a low cost way
to derive the bias voltage for LCD displays in systems where
only 3 or 5 volt digital voltages are available.
Output
Model
Min
Nom
Max
VDC
mA
The LCD series converts 3 or 5 volt inputs to an isolated 25
voltsDCatupto750milliwattsofpower. Thesimple4terminal
operation allows for quick system design.
3S25.015LCD
5S25.030LCD
3.0
4.5
3.3
5.0
3.6
5.5
25
25
15
30
Load Regulation,
25% to 100% Load
25% Typical
The isolated output allows the LCD converter to be
connected in either a positive output mode for color displays
or as a negative bias for monochrome displays.
Line Regulation
Efficiency
1.3% / % VIN Typical
60% Typical
The LCD series is packaged in an environmentally rugged
plastic case. The use of special potting compounds allows the
converters to be water washed and operate over the full -40°
to 85°C industrial temperature range.
Operating Temperature Range
(Case)
-40° to 85°C
Specifications subject to change without notice.
For a positive LCD Bias voltage connect pin 3 to pin 2 and
take the positive bias voltage from pin 4. For a negative bias
voltage connect pin 4 to pin 2 and take the negative bias
voltage from pin 3. These connections are shown in figure 2.
Applications Information
Connecting To Your System
Figure 1 shows the input and output connections for the LCD
series of converters. The output should be bypassed with at
least a 4.7 µF tantalum capacitor. For lower noise operation,
especially at low temperatures this value may be increased to
10 or 20 µF as required.
A
Figure 1.
The output of the LCD series should be bypassed with a 4.7 to 20µF
tantalum. The input may need to be bypassed if the converter is
more than 1 to 2 inches from the input source or if the source
impedance is high.
Figure 2.
The input should be bypassed if it is more than about 1 or
2inchesfromtheinputsupplyoriftheinputsourceimpedance
is large. A 1 to 20 µF tantalum works well for the input bypass.
The LCD series may be connected to supply either a positive or
negative LCD bias voltage as shown.
2401 Stanwell Drive
•
Concord, California 94520
•
Ph: 925/687-4411 or 800/542-3355
•
Fax: 925/687-3333
•
www.calex.com
•
Email: sales@calex.com
eco: 010918-2, 9/2001
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