Description
The STEVAL-SCR002V1 introduces a simple and innovative AC-DC front-end circuit
that allows the designer to perform an inrush current limitation in any converter with
input rectifier bridge topologies.
Based on a discrete control circuit made of one Z0110MN SMD triac and two
STTH110A diodes, it offers a compact and non-insulated high voltage driver for the
mains SCR. The drive circuit synchronizes the SCR gate signals with the AC line
polarity and powers directly the SCR gate from the mains. This operation does not
generate reverse losses in the SCRs.
This STEVAL-SCR002V1 solid-state solution provides a high reliability, a long service
lifetime, an electromagnetic interference reduction, and a faster response compared
to electromechanical solutions.
This solution is also compatible with an inrush current limitation performed either in
the NTC/PTC bypass mode or in the MCU phase-control mode.
The enable control pin of the SCR driver is referenced to GND_DC. Therefore, an
uninsulated power supply or a direct control by the MCU can be used.
With five wires to connect, the STEVAL-SCR002V1 is designed for an easy
implementation on existing AC-DC converters for plug-and-play tests.
It is suitable for applications with an RMS current up to 4.3 A (at an ambient
temperature of 60°C).

Features
• Two TN1605H-6T 16 A - 600 V Hi Tj SCRs in a TO-220 package, used to
bypass the inrush resistor
• Compact solution: 43.6 x 28.5 mm (≈ 1.8 sq in)
• Compatible with AC-DC converters with or without PFC in all modes: CCM,
CRM, and DCM
• Enable signal (EN = 3.3 V to 15 V) versus GND_DC (DC or PWM signal)
• Suitable for applications from 50 W up to 1000 W (230 VRMS, TAMB = 60°C)
• Compliant with AC or DC input voltage: 90-265 VAC, 50/60 Hz, or 120-400 VDC
• Robust, immune (2 kV IEC 61000-4-5, 4 kV IEC 61000-4-4)
• Low EMI noise (EN55014 and EN55022) solution