Test Configurations

Peak-to-Peak Output Noise Measurement Test

Use a Cout 4.7uF 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.

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

logic low and on during a logic high.

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 -0.3V to 1.2V.

A logic high is 3.0V to 5.0V.

The maximum sink current at on/off terminal during a logic

low is -100 uA.

The maximum allowable leakage current of the switch at

on/off terminal (3.0 to 5.0V) is 50uA.

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.

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 22uF

capacitors at the output.

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 100uF for the 5V input devices and a 33uF

for the 12V and 24V devices.

Output Voltage Trim

Connecting the external resistor (Radj) between the Vadj

and +Vout pins decreases the output voltage to set the point

as defined in the following equation:

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 ambient temperature must be kept below 70°C.

The derating curves are determined from measurements

obtained in an experimental apparatus.

IDS100 Series

+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

+Out

-Out

+Vin

-Vin

Load

DC Power

Source

+

-

Fuse

On/Off

Vadj

Radj

IDS101 and IDS121 ==>Rx=2130[

Output Voltage range is 1.8-3.3VDC.

IDS112 and IDS122==>Rx=3840[

Output Voltage range is 3.0-5.0VDC.

VR1=

(Rx．1200) ．(Vo-1.195)

(Rx．1.195) -[1200．(Vo-1.195)]

DUT

Position of air velocity

probe and thermocouple

50mm / 2in

Air Flow

15mm / 0.6in