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MER1 Series

1kVDC Isolated 1W Single Output DC/DC Converters

2009/09/15

KDC_MER1.A01 Page 3 of 6

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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

OSCILLOSCOPE

Y INPUT

SUPPLY

C1 C2 C3

R1

T1

R2

Input

Output

DC/DC Converter

R LOAD

+

+

-

-

Typical Start-Up Wave Form

Start-up time

Start-up time

μs

μs

MER1S0505SC

600

MER1S1512SC

3375

MER1S0509SC

1730

MER1S1515SC

5090

MER1S0512SC

3780

MER1S2405SC

431

MER1S0515SC

6700

MER1S2409SC

245

MER1S1205SC

750

MER1S2412SC

1634

MER1S1209SC

2605

MER1S2415SC

2682

MER1S1212SC

3754

MER1S4805SC

512

MER1S1215SC

5280

MER1S4809SC

1432

MER1S1505SC

704

MER1S4812SC

2528

MER1S1509SC

1859

MER1S4815SC

3884