FOD2741A, FOD2741B, FOD2741C
Optically Isolated Error Amplifier
Features
Description
■ Optocoupler, precision reference and error amplifier in
The FOD2741 Optically Isolated Amplifier consists of the
popular KA431 precision programmable shunt reference
and an optocoupler. The optocoupler is a gallium arsenide (GaAs) light emitting diode optically coupled to a
silicon phototransistor. It comes in 3 grades of reference
voltage tolerance = 2%, 1%, and 0.5%.
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■
■
■
■
■
single package
2.5V reference
CTR 100% to 200%
5,000V RMS isolation
UL approved E90700, Volume 2
CSA approval 1296837
VDE approval 40002463
BSI approval 8702, 8703
Low temperature coefficient 50ppm/°C max.
FOD2741A: tolerance 0.5%
FOD2741B: tolerance 1%
FOD2741C: tolerance 2%
Applications
■ Power supplies regulation
The Current Transfer Ratio (CTR) ranges from 100% to
200%. It also has an outstanding temperature coefficient
of 50 ppm/°C. It is primarily intended for use as the error
amplifier/reference voltage/optocoupler function in isolated AC to DC power supplies and DC/DC converters.
When using the FOD2741, power supply designers can
reduce the component count and save space in tightly
packaged designs. The tight tolerance reference eliminates the need for adjustments in many applications.
The device comes in a 8-pin dip white package.
■ DC to DC converters
Functional Bock Diagram
NC
Package Outlines
1
8 LED
C
2
7 FB
E
3
6 COMP
8
1
8
NC
4
©2004 Fairchild Semiconductor Corporation
FOD2741A, FOD2741B, FOD2741C Rev. 1.0.1
5 GND
8
1
1
www.fairchildsemi.com
FOD2741A, FOD2741B, FOD2741C — Optically Isolated Error Amplifier
August 2008
