STMicroelectronics STEVAL-ISA105V1

Overview

STEVAL-ISA105V1 from STMicroelectronics is a demonstration board implementing a quasi-resonant flyback power supply for energy metering and power line modem applications, based on the ALTAIR04-900 primary-side regulated switcher. It delivers isolated outputs of –5 V/70 mA, 3.3 V/30 mA, 12 V/2 mA, and 5 V_ISO/2 mA, with peak output power up to 7.5 W during transmission mode and >75% efficiency at 230 Vac.

For engineers reviewing the STEVAL-ISA105V1 datasheet, STEVAL-ISA105V1 pinout, STEVAL-ISA105V1 application, or STEVAL-ISA105V1 equivalent, this board provides validated reference design for mains-connected metering systems requiring galvanic isolation >2.7 kV, wide input range (90–265 Vac), and optocoupler-free regulation using primary-side sensing.

Technical Context

The board implements a quasi-resonant flyback topology with primary-side regulation, eliminating optocouplers and secondary-side references. It uses the ALTAIR04-900 IC - integrating a 900 V avalanche-rugged power switch and current-mode PWM controller - enabling direct rectified-mains operation with minimal external components.

Input-to-output galvanic isolation exceeds 2.7 kV, supporting safety-critical metering environments. Output ripple is maintained below 100 mV pk-pk across all rails, and short-circuit protection is implemented at the system level for robust field operation.

Key Specifications

Availability

STEVAL-ISA105V1 is available at Aetrix Electronics and suitable for energy metering, power line communication (PLC) modem integration, and smart grid infrastructure projects requiring stable component supply, regulatory-compliant isolation, and validated reference designs.

Supply support for STEVAL-ISA105V1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing microcontrollers, power ICs, analog devices, and sensors for industrial, automotive, and consumer applications.

The STEVAL evaluation board series supports rapid prototyping and compliance validation for ST's power management and metering solutions, targeting utility-grade accuracy, safety certification readiness, and interoperability with PLC standards like PRIME and G3-PLC.

FAQ

What is the primary function of the STEVAL-ISA105V1 board?

The STEVAL-ISA105V1 is a fully assembled demonstration board that implements a certified-ready, isolated multi-rail power supply for energy meters and PLC modems. It validates the ALTAIR04-900 quasi-resonant flyback controller in real-world utility environments, delivering four regulated outputs including an isolated 5 V rail for modem interface circuits.

Does this board support both 50 Hz and 60 Hz mains frequencies?

Yes - the board is designed for 50 Hz ±3 Hz mains operation, as specified in its documentation. While not explicitly rated for 60 Hz, the ALTAIR04-900 controller's adaptive quasi-resonant timing and wide input voltage range (90–265 Vac) enable functional operation at 60 Hz in most deployments, though full certification would require validation per regional standards.

Can the STEVAL-ISA105V1 be used as a production power supply?

No - it is a demonstration board intended for design evaluation and reference implementation only. It lacks production-level certifications (e.g., UL/EN 62368-1), conformal coating, and long-term reliability qualification. For production, ST recommends designing derivative power supplies based on the validated schematic and layout guidelines provided in Doc ID 023539.

What safety certifications does this board meet?

The board implements >2.7 kV galvanic isolation and complies with RoHS, but it is not itself certified to end-equipment standards (e.g., IEC 62052-11 or EN 50470). Its design follows ST's guidance for meeting reinforced insulation requirements in Class I metering applications, and serves as a foundation for achieving final product certification when integrated into a complete meter assembly.