July 2016
DocID029457 Rev 1
1/43
www.st.com
UM2076
User manual
Getting started with the STEVAL-ISF003V1
Introduction
The STEVAL-ISF003V1 evaluation board allows the inrush-current which charges a DC bus capacitor to
be limited to comply with standard IEC 61000-3-3. This inrush current limitation is based on a soft-start
procedure of the mixed bridge diodes and SCRs rectifier using progressive phase control at board start-
up.
This solution can also drastically reduce standby losses as the DC bus can be totally disconnected from
the AC mains when it does not have to operate. DC bus deactivation is simply achieved by turning off
SCRs, without requiring an additional relay to open the circuit in standby.
The steady-state losses are also reduced, thanks to the removal of the NTC / PTC resistor traditionally
used to limit inrush current. Also in this case, no relay is required to bypass this resistor as it is no longer
used.
Figure 1: STEVAL-ISF003V1 board (top view)
