Description

The STEVAL-ISA125V1 is a 5 V, 2 A

demonstration application with 3.3 A peak current

capability of 1.9 sec, using the new VIPer28LN

offline high-voltage converter from

STMicroelectronics.

In some applications, an SMPS can have load

peaks which may be two or more times as high as

the power it is supposed to deliver, though only

for a short time compared to the thermal time

constants of the power components. Typical

examples of such loads include printers and

audio systems.

In such cases, it is more cost-effective to

thermally design the system for maximum

continuous power and not for peak power

demand, which is sustained only for a limited

time.

Such a design is possible thanks to the EPT

function of the VIPer28LN, which allows

designers to fix the maximum time window during

which the converter is able to manage the peak

power and still maintain output voltage regulation.

If the overload period exceeds the time window,

the converter is automatically shut down and

enters auto-restart mode until the overload is

removed, thus preventing damage to the power

components.

Features

• Input voltage range: 90 VRMS - 265 VRMS

• Output voltage: 5 V

• Max output current: IOUT max = 2 A

• Peak output current: IOUT pk = 3 A

• Precision of output regulation: ΔVOUT_LF ±5

• High frequency output voltage ripple:

ΔVOUT_HF = 50 mV

• Max ambient operating temperature: TA =

60 ºC

• 800 V avalanche-rugged power section

• PWM operation at 60 kHz with frequency

jittering for lower EMI

• Limiting current with adjustable set point

• On-board soft-start

• Safe auto-restart after a fault condition; low

standby power (< 50 mW at 265 Vac).

• Adjustable, accurate overvoltage protection,

thermal shutdown with hysteresis, delayed

overload protection