STEVAL-ISA137V1

The STEVAL-ISA137V1 is a complete DC/DC & AC/DC (Off-Line) switch-mode power supply (SMPS) switching evaluation board designed to be used as a DC/DC controller or AC/DC/ DC converter or as a application-specific demonstration platform for high power density applications. It features a high-performance, frequency-modulated, and synchronous-rectifier controller IC, ST1S10, based on ST\'s patented, integrated, high- speed, low-power control IC technology.

The STEVAL-ISA137V1 is designed to achieve low power losses, high system efficiency, and good power quality. The board can deliver output power of up to 36W at 90-265Vac input. It has robust protections such as over-voltage, over-current, over-temperature, and short-circuit as well as a slow-start feature. This board is suitable for a wide range of applications such as set-top boxes, televisions, white goods, and solar inverters.

Features of STEVAL-ISA137V1

• Low power losses, high system efficiency, and exact power quality
• Output power up to 36W
• Input voltage from 90 to 265Vac
• Automatic inrush current limitation and over-voltage protection (OVP)
• Synchronously rectified topology for high efficiency
• Strong protections such as over-current (OCP), short-circuit (SCP), over-temperature (OTP), and soft-start (SSP)
• Patented IC implementations

Working Principle of STEVAL-ISA137V1

The STEVAL-ISA137V1 is a complete DC/DC & AC/DC (Off-Line) switch-mode power supply evaluation board designed to be used in applications such as set-top boxes, televisions, white goods, and solar inverters. The board consists of a high-performance, frequency-modulated, and synchronous-rectifier controller IC, ST1S10. This IC is based on ST\'s patented, integrated, high- speed, low-power controller IC technology and includes auto-resonant and current-mode control features for quick and efficient switching of the MOSFETs.

The board consists of a rectifier bridge, a high-frequency transformer, a synchronous rectifier, two MOSFETs for primary and secondary side switching, a clamping for inrush current limiting, and a power supply IC, MC33602A, for softstart limiting/regulation. In addition, several protection circuits are added such as OCP, OTP, and SCP.

In the STEVAL-ISA137V1, the secondary side of the transformer is connected to the primary bridge rectifier, and the output filter is connected on the secondary side. When power is applied to the primary side, the transformer transfers power to the secondary side and the rectifier bridge rectifies it. The power is then filtered and regulated by the power supply IC. The output voltage is monitored for over-voltage conditions, and the output current limit is enforced by the power supply IC. The ST1S10 synchronous-rectifier controller IC controls the MOSFETs on the primary and secondary sides of the transformer to achieve high efficiency.

Conclusion

The STEVAL-ISA137V1 evaluation board is designed to demonstrate the performance of the highly efficient, frequency-modulated, and synchronous-rectifier controller IC, ST1S10, for DC/DC and AC/DC applications. This board offers several robust protections such as OVP, OTP, OCP, and SCP as well as an automatic inrush current limitation and soft-start feature. The superior efficiency of the STEVAL-ISA137V1 makes it an ideal choice for powering various types of electronic devices.