FOD2712 — Optically Isolated Error Amplifier
©2003 Fairchild Semiconductor Corporation www.fairchildsemi.com
FOD2712 Rev. 1.0.0
December 2008
FOD2712
Optically Isolated Error Amplifier
Features
■
Optocoupler, precision reference and error amplifier in
single package
■
1.240V ± 1% reference
■
CTR 100% to 200%
■
2,500V RMS isolation
■
VDE approval 136616
■
BSI approval 8661 and 8662
■
UL approval E90700
■
CSA approval 1113643
Applications
■
Power system for workstations
■
Telecom central office supply
■
Telecom bricks
Description
The FOD2712 Optically Isolated Amplifier consists of the
popular RC431A precision programmable shunt refer-
ence and an optocoupler. The optocoupler is a gallium
arsenide (GaAs) light emitting diode optically coupled to
a silicon phototransistor. The reference voltage toler-
ance is 1%. The current transfer ratio (CTR) ranges from
100% to 200%.
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 FOD2712, power supply designers can
reduce the component count and save space in tightly
packaged designs. The tight tolerance reference elimi-
nates the need for adjustments in many applications.
The device comes in a compact 8-pin small outline
package.
Schematic Package Outline
1
2
3
4 5
6
7
8
LED
FB
COMP
GND
NC
C
E
NC
