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USER NOTES

Input Voltage

The recommended operating maximum DC input

voltage is 40V inclusive of the ripple voltage.

Case Grounding

The module case is internally connected to pin 2

and pin 8.

The PCB area below the module can be used as

an effective sixth side shield against EMI.

Thermal Characteristics

The case-to-ambient thermal resistance of the

GS-R51212 module is about 5

°C/W. This produces

a 50

°C temperature increase of the module surface

for a 10W of internal power dissipation.

Depending on the ambient temperature and/or on

the power dissipation, an additional heatsink or

forced ventilation may be required.

Input Impedance

The module has an internal capacitor connected

between the input pins in order to assure PWM

stability. This capacitor cannot handle large values

of high frequency ripple current, and it can be

permanently damaged if the primary energy source

impedance is not adequate.

The use of an external low ESR, high ripple current

capacitor located as close to the module as possi-

ble is recommended. Suitable capacitors should

Ω at

100 kHZ. When space is a limitation, a 22

µF ce-

ramic multilayer capacitor must be connected to the

module input pins.

Module Protection

The module is protected against occasional and

permanent short circuits of the output pins to

ground, as well as against output current overload.

When the output current at 5V output exceeds the

maximum value, the output is automatically dis-

abled. After a fixed time the module starts again in

a soft mode. The cycle is repeated until the overload

condition is removed.

A crow-bar output overvoltage protection is acti-

6.37V.

Output Current

The output current of the main output is 3.5A. The

max output current of the two 12V outputs is a

function of the input voltage and of the main output

current as shown in fig. 1.

If the main current is zero, no voltage will be avail-

able on the 12V outputs.

Figure 1. Output Current Capability vs. Operat-

ing Conditions

Figure 2. Reset Operation

Figure 3. Typical application

GS-R51212