WRB-YT-1W Series
TEMPERATURE DERATING
ISOLATION SPECIFICATIONS
WRB2405YT-1W
Item
Test Conditions
Min.
Typ.
Max.
Units
Isolation voltage
Tested for 1 minute and 1mA max
Test at 500VDC
1000
1
VDC
GΩ
pF
Isolation resistance
Isolation capacitance
10
25
*Supply voltage must be discontinued at the end of short circuit duration.
OUTPUT SPECIFICATIONS
Item
Output power
Test Conditions
Min.
Typ.
Max.
Units
Refer to products program
With external input/output capacitors
10% load to 100% load, with external input/output capacitors
Low line to high line
0.1
1
±2
1
W
%
Voltage set point accuracy
Load regulation
±1
0.1
0.2
%
Line regulation
1
%
Voltage trim range
Ripple & noise
-10
50
±10
150
700
%/℃
mVp-p
kHz
20MHz Bandwidth,all output types
100
Switching frequency
WRB2412YT-1W
APPLICATION NOTE
ISOLATION VOLTAGE
“Hi Pot Test”,“Flash Tested”,“Withstand Voltage”, “Proof Voltage”, “Dielectric Withstand Voltage” &
“Isolation Test Voltage” are all terms that relate to the same thing, a test voltage, applied for a specify
time, across a component designed to provide electrical isolation, to verify the integrity of that isolation.
WRB-YT-1W series of DC/DC converters are all 100% production tested at their stated isolation
voltage. This is 1kVDC for 1 second.
A question commonly asked is, “What is the continuous voltage that can be applied across the part
in normal operation?”
For a part holding no specific agency approvals, such as the WRB-YT-1W series, both input and
output should normally be maintained within SELV limits i.e. less than 42.4V peak, or 60VDC. The
isolation test voltage represents a measure of immunity to transient voltages and the part should never
be used as an element of a safety isolation system. The part could be expected to function correctly with
several hundred volts offset applied continuously across the isolation barrier; but then the circuitry on
both sides of the barrier must be regarded as operating at an unsafe voltage and further
isolation/insulation systems must form a barrier between these circuits and any user-accessible circuitry
according to safety standard requirements.
WRB2415YT-1W
REPEATED HIGH-VOLTAGE ISOLATION TESTING
It is well known that repeated high-voltage isolation testing of a barrier component can actually
degrade isolation capability, to a lesser or greater degree depending on materials, construction and
environment. The WRB-YT-1W series has toroidal isolation transformers, with no additional insulation
between primary and secondary windings of enameled wire. While parts can be expected to withstand
several times the stated test voltage, the isolation capability does depend on the wire insulation. Any
material, including this enamel (typically polyurethane) is susceptible to eventual chemical degradation
when subject to very high applied voltages thus implying that the number of tests should be strictly
limited. We therefore strongly advise against repeated high voltage isolation testing, but if it is absolutely
required, that the voltage be reduced by 20% from specify test voltage.
This consideration equally applies to agency recognized parts rated for better than functional isolation
where the wire enamel insulation is always supplemented by a further insulation system of physical
spacing or barriers.
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Technical Enquiries-Email:tech@microdc.cn Tel:0086-20-86000646
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