Test Configurations

Input Reflected-Ripple Current Test Setup

Input reflected-ripple current is measured with a inductor

Lin (4.7uH) and Cin (220uF, ESR < 1.0[ 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.

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.

Design & Feature Considerations

Remote On/Off

Positive logic remote on/off turns the module on during a

logic high voltage on the remote on/off pin, and off during a

logic low.

To turn the power module on and off, the user must supply

a switch to control the voltage between the on/off terminal and

the -Vin terminal.

The switch can be an open collector or equivalent.

A logic low is -0.7V to 0.8V.

A logic high is 2.5V to 5.5V.

The maximum sink current of the switch at on/off terminal

during a logic low is -300 uA.

The maximum sink current of the switch at on/off terminal

during a logic high is -200uA or open.

Maximum Capacitive Load

The MSIW2000 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

capacitive load for single outputs.

The maximum capacitance can be found in the data sheet.

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 < 1.0[ at 100

KHz) capacitor of a 4.7uF for the 24V input devices and a

2.2uF for the 48V devices.

MSIW2000 Series

6

MINMAX

REV:4 2008/10

+Out

-Out

+Vin

-Vin

DC / DC

Converter

Load

Battery

+

Lin

+

Cin

To Oscilloscope

Current

Probe

+Out

-Out

+Vin

-Vin

Dual Output

DC / DC

Converter

Resistive

Load

Scope

Copper Strip

Cout

Com.

Scope

Cout

+Out

-Out

+Vin

-Vin

Single Output

DC / DC

Converter

Resistive

Load

Scope

Copper Strip

Cout

+

+Out

-Out

+Vin

-Vin

DC / DC

Converter

Load

DC Power

Source

+

-

Cin