Input Source Impedance

The power module should be connected to a low

ac-impedance input source. Highly inductive source

impedances can affect the stability of the power module.

In applications where power is supplied over long lines and

output loading is high, it may be necessary to use a capacitor

at the input to ensure startup.

Capacitor mounted close to the power module helps

ensure stability of the unit, it is recommended to use a good

quality low Equivalent Series Resistance (ESR < 1.0[ at 100

KHz) capacitor of a 33uF for the 12V input devices and a 10uF

for the 24V and 48V devices.

Output Ripple Reduction

A good quality low ESR capacitor placed as close as

practicable across the load will give the best ripple and noise

performance.

To reduce output ripple, it is recommended to use 4.7uF

capacitors at the output.

Maximum Capacitive Load

The MPW1000 series has limitation of maximum

connected capacitance at the output.

The power module may be operated in current limiting

mode during start-up, affecting the ramp-up and the startup

time.

For optimum performance we recommend 330uF

maximum capacitive load for dual outputs, 1000uF capacitive

load for 12V & 15V outputs and 10000uF capacitive load for

3.3V & 5V outputs.

The maximum capacitance can be found in the data sheet.

Thermal Considerations

Many conditions affect the thermal performance of the

power module, such as orientation, airflow over the module

and board spacing. To avoid exceeding the maximum

temperature rating of the components inside the power

module, the case temperature must be kept below 105°C.

The derating curves are determined from measurements

obtained in an experimental apparatus.

MPW1000 Series

REV:0 2005/04

MINMAX

7

+

+Out

-Out

+Vin

-Vin

DC / DC

Converter

Load

DC Power

Source

+

-

Cin

+Out

-Out

+Vin

-Vin

Load

DC Power

Source

+

-

Cout

Com.

Dual Output

DC / DC

Converter

+Out

-Out

+Vin

-Vin

Load

DC Power

Source

+

-

Cout

Single Output

DC / DC

Converter

DUT

Position of air velocity

probe and thermocouple

50mm / 2in

Air Flow

15mm / 0.6in