By incorporating an integrated
fault feedback optocoupler,
our soon to be introduced
HCPL-3160 will provide even
lower cost, area efficient IGBT
gate drive by offering
desaturation or over-current
detection and local IGBT
shutdown.
For interfacing to an Intelligent
Power Module’s (IPM) power
transistor gate drive circuitry, HP
introduced the HCPL-4506
family of optocouplers. Available
in several 8-pin package styles,
the HCPL-4506 (PDIP),
HCPL-0466 (SO8), and
HCNW4506 (Widebody PDIP)
provide significant performance
advantages for such design
critical specifications as current
transfer ratio, propagation delay,
and common mode rejection.
Current Sense
As extensions to its family of
HCPL-7800 Analog Isolation
Amplifiers for motor drive
current sensing, HP introduced
the HCPL-7820, HCPL-7825,
and HCPL-7840. Each offers a
breakthrough combination of
unequaled CMR performance,
compact size, -40°C to +100°C
performance guarantees, and
overall lower solution cost as
compared to the predominant
form of competition.
Most recently, HP introduced the
HCPL-7860 and HCPL-7870,
which together form an Isolated
15-bit Programmable A/D Con-
verter that delivers the reliabil-
ity, small size, superior isolation
and over temperature perform-
ance motor drive designers need
to accurately measure current at
half the price of traditional
solutions. Peformance features
include:
• 12-bit Linearity
• Resolution/Speed trade-off with
5 different Conversion Modes
• 12-bit effective resolution with
18 µs signal delay
• 14-bit effective resolution with
95 µs signal delay
• Fast 3 µs Over-Range Detection
• ±200 mV Input Range with
single 5 V supply
• Internal Reference Voltage
• Offset Calibration
• -40°C to +85°C Operating
Temperature Range
• 15 kV/µs Isolation Transient
Immunity
• UL, CSA and VDE Regulatory
Approval
Product Safety
Regulations and
Optocouplers
Optocouplers optically transfer a
signal from one circuit to another
circuit within or between elec-
trical equipment. In addition to
providing common-mode signal
isolation, optocouplers are often
used to provide high voltage
insulation. This is done by pre-
venting voltage transients on a
signal line from affecting the
equipment, and by protecting the
operator from high voltage which
may be present inside the
equipment.
Because optocouplers perform a
safety function, they are tested
and qualified for use in each
country, usually through national
third party safety agencies, both
at the component level and
system level. Third party safety
agencies are often private
organizations which have
governmental authority and
develop standards for many
aspects of equipment manufac-
ture (e.g., safety, electromagnetic
interference reduction, protecting
the environment).
In Europe, standardization for
equipment specifications is well
in progress. The European
Economic Community (EEC)
established a target date of
January 1, 1992 for all member
countries and manufacturers to
be in compliance with the EEC
directives. Transitional periods
have been established by each
member country when they will
begin enforcing and accepting
the European norms(EN), by
creating national laws. The EEC
is now known as the European
Union(EU), composed of 15
countries.
At this time, optocouplers have
not had the benefit of harmonized
test requirements, i.e., agreement
among countries and their
respective national agencies.
Testing, approval, recognition
and certification must still be
obtained from each country
where optocouplers will be used.
Each country tests optocouplers
to different standards, either
component based or system/
equipment based.
Each Hewlett-Packard optocoup-
ler data sheet provides the design
engineer with sufficient informa-
tion to determine which opto-
couplers are suitable for an
application. Although some
equipment standards are more
specific than others and
definitions may vary, each