MSIW1000 SERIES

DC/DC CONVERTER 3W, SMD-Package

18, Sin Sin Road, An-Ping Industrial District, Tainan 702, Taiwan

Tel: 886-6-2923150

Fax: 886-6-2923149

2012/01/10 REV:4

Page 4 of 4

Minmax Technology Co., Ltd.

Test Configurations

Input Reflected-Ripple Current Test Setup

Input reflected-ripple current is measured with a inductor Lin (4.7uH) and Cin (220uF, ESR < 1.0Ω at 100 KHz) to simulate source impedance. Capacitor Cin, offsets

possible battery impedance. Current ripple is measured at the input terminals of the module, measurement bandwidth is 0-500 KHz.

+Out

-Out

+Vin

-Vin

DC / DC

Converter

Load

Battery

+

Lin

+

Cin

To Oscilloscope

Current

Probe

Peak-to-Peak Output Noise Measurement Test

Use a Cout 0.47uF ceramic capacitor. Scope measurement should be made by using a BNC socket, measurement bandwidth is 0-20 MHz. Position the load

between 50 mm and 75 mm from the DC/DC Converter.

+Out

-Out

+Vin

-Vin

Single Output

DC / DC

Converter

Resistive

Load

Scope

Copper Strip

Cout

Copper Strip

+Out

-Out

+Vin

-Vin

Dual Output

DC / DC

Converter

Resistive

Load

Scope

Copper Strip

Cout

Com.

Scope

Cout

Copper Strip

Copper Strip

Design & Feature Considerations

Overcurrent Protection

To provide protection in a fault (output overload) condition, the unit is equipped with internal current limiting circuitry and can endure current limiting for an unlimited

duration. At the point of current-limit inception, the unit shifts from voltage control to current control. The unit operates normally once the output current is brought back

into its specified range.

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 <

1.0Ω at 100 KHz) capacitor of a 3.3uF for the 12V input devices and a 1.5uF for the 24V and 48V devices.

+

+Out

-Out

+Vin

-Vin

DC / DC

Converter

Load

DC Power

Source

+

-

Cin

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 3.3uF capacitors at the output.

+Out

-Out

+Vin

-Vin

Load

DC Power

Source

+

-

Cout

Single Output

DC / DC

Converter

+Out

-Out

+Vin

-Vin

Load

DC Power

Source

+

-

Cout

Com.

Dual Output

DC / DC

Converter

Load

Cout

Maximum Capacitive Load

The MSIW1000 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 180uF maximum capacitive load for dual outputs and 4700uF capacitive load

for single 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 90

℃. The derating curves are determined from

measurements obtained in a test setup.

DUT

Position of air velocity

probe and thermocouple

50mm / 2in

Air Flow

15mm / 0.6in