May 2010
FODM8071
3.3V/5V Logic Gate Output Optocoupler with
High Noise Immunity
Features
Description
■ High noise immunity characterized by common mode
The FODM8071 is a 3.3V/5V high-speed logic gate
output Optocoupler, which supports isolated communi-
cations allowing digital signals to communicate between
systems without conducting ground loops or hazardous
voltages. It utilizes Fairchild’s patented coplanar packag-
ing technology, Optoplanar , and optimized IC design to
achieve high noise immunity, characterized by high com-
mon mode rejection specifications.
rejection
– 20kV/µs minimum common mode rejection
■ High speed
– 20Mbit/sec date rate (NRZ)
®
– 55ns max. propagation delay
– 20ns max. pulse width distortion
– 30ns max. propagation delay skew
■ 3.3V and 5V CMOS compatibility
This high-speed logic gate output optocoupler, housed in
a compact 5-Pin Mini-Flat package, consists of a high-
speed AlGaAs LED at the input coupled to a CMOS
detector IC at the output. The detector IC comprises an
integrated photodiode, a high-speed transimpedance
amplifier and a voltage comparator with an output driver.
The CMOS technology coupled with a high efficiency
LED achieves low power consumption as well as very
high speed (55ns propagation delay, 20ns pulse width
distortion).
■ Specifications guaranteed over 3V to 5.5V supply
voltage and -40°C to +110°C temperature range
■ Safety and regulatory approvals
– UL1577, 3750 VAC
for 1 min.
RMS
– IEC60747-5-2 (pending)
Applications
■ Microprocessor system interface
2
– SPI, I C
■ Industrial fieldbus communications
– DeviceNet, CAN, RS485
Related Resources
■ www.fairchildsemi.com/products/opto/
■ Programmable logic control
■ Isolated data acquisition system
■ Voltage level translator
■ www.fairchildsemi.com/pf/FO/FOD8001.html
■ www.fairchildsemi.com/pf/FO/FOD0721.html
Functional Schematic
Truth Table
V
V
ANODE 1
6
5
DD
O
LED
Off
Output
High
On
Low
CATHODE
GND
3
4
©2008 Fairchild Semiconductor Corporation
FODM8071 Rev. 1.0.7
www.fairchildsemi.com