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