STMicroelectronics STEVAL-ISA014V1

Overview

STEVAL-ISA014V1 from STMicroelectronics is a reference design evaluation board implementing a flyback AC-DC adapter using the VIPer12AS primary-side controller, delivering 6 V at 600 mA (3.6 W) with 65–67% efficiency and 60 kHz switching frequency for cellular phone travel adapters.

For engineers reviewing the STEVAL-ISA014V1 datasheet, STEVAL-ISA014V1 pinout, STEVAL-ISA014V1 application, or STEVAL-ISA014V1 equivalent, this board supports secondary-side voltage/current regulation via optocoupler feedback, includes overtemperature/overcurrent/overvoltage protection, and meets EU standby power requirements (<100 mW at 100 V_dc).

Technical Context

The STEVAL-ISA014V1 implements a standard flyback topology with primary-side control by the VIPer12AS IC and secondary-side regulation via an optocoupler driving the feedback pin. Input range is 85–264 V_ac, 50/60 Hz; output is tightly regulated at 6 V ±5% under full load.

It uses current-mode control with built-in high-voltage startup, auxiliary undervoltage lockout with hysteresis, and integrated protections including thermal shutdown, cycle-by-cycle current limiting, and output overvoltage clamping via Zener diode and TL431-based sensing.

Key Specifications

Availability

STEVAL-ISA014V1 is available at Aetrix Electronics and suitable for AC-DC adapter development, cellular phone charger reference design validation, and low-power flyback topology prototyping requiring stable component supply and documented ST reference implementation.

Supply support for STEVAL-ISA014V1 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 chips, and reference designs for industrial, automotive, and consumer applications.

This board belongs to ST's STEVAL series of application-specific evaluation platforms, developed to accelerate adoption of ST power ICs like VIPer12AS in cost-sensitive, certified AC-DC adapter designs.

FAQ

Is STEVAL-ISA014V1 still in production?

No - STEVAL-ISA014V1 is marked "Obsolete Product(s)" in its official ST data brief (Rev 1, March 2006). It is no longer manufactured or supported by STMicroelectronics, though functional units may remain in limited distributor stock or second-source channels.

What controller IC is used on this board?

The board uses the VIPer12AS - a high-voltage off-line converter IC integrating an 800 V avalanche-rugged MOSFET, current-mode PWM controller, startup circuit, and protection features including overtemperature, overcurrent, and overvoltage shutdown.

Can STEVAL-ISA014V1 be modified for 5 V USB output?

Yes - the output voltage is set by the TL431 + optocoupler feedback network; replacing the upper feedback resistor to adjust the divider ratio achieves 5 V output, provided the transformer turns ratio and output rectifier/diode ratings remain compatible with reduced voltage and same current.

Does this board include EMI filtering components?

Yes - the schematic includes a common-mode choke, X-capacitor across L/N, and Y-capacitors from L/N to earth, meeting basic conducted EMI requirements for Class B ITE equipment per EN55022, as validated in ST's original test report.