Low line to high line, all other outputs with external input/output capacitors
25% load to 100% load, 3.3V output with external input/output capacitors
Load regulation
25% load to 100% load, all other outputs with external input/output capacitors
BW = 20Hz to 300kHz, 3.3V output with external input/output capacitors
Ripple
1
BW = 20Hz to 300kHz, all other outputs with external input/output capacitors
BW = DC to 100MHz, 3.3V output with external input/output capacitors
Noise
BW = DC to 20MHz, all other outputs with external input/output capacitors
50
100
mV p-p
5
10
180
mV rms
mV p-p
0.2
80
0.5
120
%
mV rms
0.05
0.6
0.5
1.0
%
%
Conditions
With external input/output capacitors
Low line to high line, 3.3V output with external input/output capacitors
Min.
Typ.
±1
0.05
Max.
±5
0.25
Units
%
%
GENERAL CHARACTERISTICS
Parameter
Conditions
100% load VIN nominal 3.3V output
25% load VIN nominal 3.3V output
Switching frequency
100% load VIN nominal, all other outputs
25% load VIN nominal, all other outputs
80
290
220
560
kHz
kHz
Min.
160
290
Typ.
Max.
220
560
Units
kHz
kHz
TEMPERATURE CHARACTERISTICS
Parameter
Operation
Storage
Cooling
Free air convection
Conditions
Ambient temperature
Min.
-40
-50
Typ.
Max.
85
130
Units
℃
℃
ISOLATION CHARACTERISTICS
Parameter
Isolation test voltage
Resistance
Conditions
Flash tested for 1 second
Viso=500VDC
Min.
100
1
Typ.
Max.
Units
VDC
GΩ
TECHNICAL NOTES
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 specified time, across a component designed to provide electrical isolation, to verify the integrity of that isolation.
Microdc Professional Power Module WRB-YDK-3W 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-YDK-3W 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.
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-YDK-3W series has an EI ferrite core, 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 specified
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.
1. For lower ripple refer to circuit for reduced ripple.
Although these converters will work without external capacitors, they are necessary in order to guarantee the full parametric performance over the full line
and load range. All parts have been tested and characterized using the following values and test circuit.
Input Voltage
5V, 12V
24V, 48V
C
IN
100µF,25V(0.25Ωat 100KHz)
10µF,100V(1.5Ωat 100KHz)
Output Voltage
3.3V
5V, 12V, 15V
C
OUT
100µF, 25V (0.25Ω at 100KHz)
L
OUT
MPS# - 24100C
Not required
Test circuit, 5V, 12V and 15V output
Recommended circuit for reduced ripple 3.3V output
Output load
The minimum rated load across the whole input voltage range is 25% of the full load output. It is important to take care that the load does not fall below
this as the output ripple will greatly increase. While this condition will not harm the device the resultant increase in output ripple could cause customers’
