MEJ2 Series

5.2kVDC Isolated 2W DC/DC Converters

KDC_MEJ2C.B01 Page 4 of 7

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APPLICATION NOTES

Minimum load

The minimum load to meet datasheet specification is 10% of the full rated load across the specified input voltage range. Lower than 10% minimum loading will result

in an increase in output voltage, which may rise to typically double the specified output voltage if the output load falls to less than 5%.

Capacitive loading and start up

Typical start up times for this series, with a typical input voltage rise time of 2.2μs and output capacitance of 10μF, are shown in the table below. The product

series will start into a capacitance of 47μF with an increased start time, however, the maximum recommended output capacitance is 10μF.

Ripple & Noise Characterisation Method

Ripple and noise measurements are performed with the following test configuration.

C1

1μF X7R multilayer ceramic capacitor, voltage rating to be a minimum of 3 times the output voltage of the DC/DC converter

C2

10μF tantalum capacitor, voltage rating to be a minimum of 1.5 times the output voltage of the DC/DC converter with an ESR of less

than 100mΩ at 100 kHz

C3

100nF multilayer ceramic capacitor, general purpose

R1

450Ω resistor, carbon film, ±1% tolerance

R2

50Ω BNC termination

T1

3T of the coax cable through a ferrite toroid

RLOAD

Resistive load to the maximum power rating of the DC/DC converter. Connections should be made via twisted wires

Measured values are multiplied by 10 to obtain the specified values.

Differential Mode Noise Test Schematic

Start-up time

Start-up time

ms

ms

MEJ2S0303SC

0.89

MEJ2S1515SC

6.05

MEJ2S0305SC

1.89

MEJ2D0503SC

1.57

MEJ2S0503SC

1.08

MEJ2D0505SC

1.79

MEJ2S0505SC

2.04

MEJ2D0509SC

9.32

MEJ2S0509SC

6.5

MEJ2D0512SC

14.9

MEJ2S0512SC

8.29

MEJ2D0515SC

20.84

MEJ2S0515SC

11.4

MEJ2D1203SC

1.03

MEJ2S1203SC

0.73

MEJ2D1205SC

2.51

MEJ2S1205SC

1.61

MEJ2D1209SC

6.46

MEJ2S1209SC

4.04

MEJ2D1212SC

9.94

MEJ2S1212SC

5.51

MEJ2D1215SC

14.54

MEJ2S1215SC

7.61

MEJ2D1505SC

1.79

MEJ2S1505SC

1.33

MEJ2D1509SC

5.16

MEJ2S1509SC

3.37

MEJ2D1512SC

7.04

MEJ2S1512SC

4.47

MEJ2D1515SC

10.48

Typical Start-Up Wave Form

OSCILLOSCOPE

Y INPUT

SUPPLY

C1 C2 C3

R1

T1

R2

Input

Output

DC/DC Converter

R LOAD

+

+

-

-