.38 Watt LCD Single Series DC/DC Converters
Features
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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
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.
The LCD series converts 3 or 5 volt inputs to an isolated 25
volts DC at up to 750 milliwatts of power. The simple 4 terminal
operation allows for quick system design.
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.
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擄
to 85擄C industrial temperature range.
Model
Selection Chart
Input Range
VDC
Min
3S25.015LCD
5S25.030LCD
Load Regulation,
25% to 100% Load
Line Regulation
Efficiency
Operating Temperature Range
(Case)
3.0
4.5
Nom
3.3
5.0
Max
3.6
5.5
25% Typical
1.3% / % VIN Typical
60% Typical
-40擄 to 85擄C
Output
VDC
25
25
mA
15
30
Specifications subject to change without notice.
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 碌F tantalum capacitor. For lower noise operation,
especially at low temperatures this value may be increased to
10 or 20 碌F as required.
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.
A
Figure 1.
The output of the LCD series should be bypassed with a 4.7 to 20碌F
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.
The input should be bypassed if it is more than about 1 or
2 inches from the input supply or if the input source impedance
is large. A 1 to 20 碌F tantalum works well for the input bypass.
Figure 2.
The LCD series may be connected to supply either a positive or
negative LCD bias voltage as shown.
2401 Stanwell Drive 鈥?Concord, California 94520 鈥?Ph: 925/687-4411 or 800/542-3355 鈥?Fax: 925/687-3333 鈥?www.calex.com 鈥?Email: sales@calex.com
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eco: 010918-2, 9/2001
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