MEW1000 SERIES

DC/DC CONVERTER 2W, SIP-Package

Test Setup

Input Reflected-Ripple Current Test Setup

Input reflected-ripple current is measured with a inductor Lin (4.7µH) and Cin (220µF, 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.

+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 0.47µF 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

Technical Notes

Remote On/Off

Negative logic remote on/off turns the module off during a logic high voltage on the remote on/off pin, and on 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.

Alogic high is 2.9V to 15V. Alogic low is under 0.6 VDC or open circuit, drops down to 0VDC by 2mV/℃. The maximum sink current at on/off terminal during a

logic low is 1 mA. The maximum allowable leakage current of the switch at on/off terminal =(under 0.6VDC or open circuit) is 1mA.

Maximum Capacitive Load

The MEW1000 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. 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 on the input to insure startup.

By using a good quality low Equivalent Series Resistance (ESR < 1.0 at 100 kHz) capacitor of a 1.5µF for the 24V and 48V devices, capacitor mounted close to the

power module helps ensure stability of the unit.

+

+Out

-Out

+Vin

-Vin

DC / DC

Converter

Load

DC Power

Source

+

-

Cin

Output Ripple Reduction

Agood 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 3.3µF 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

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

Total Power In

Total Power International, Inc

Toll Free: 877-646-0900

www.total-power.com

Total Power International, Inc.