STMicroelectronics STEVAL-ISA007V1

Overview

STEVAL-ISA007V1 from STMicroelectronics is a high-power 3-phase auxiliary power supply evaluation board based on the L5991 PWM controller and STC08DE150HV ESBT, delivering dual regulated outputs (24V/6.25A and 5V/75mA) plus a 15V auxiliary rail, with 150W max output power, >85% efficiency, and mixed-mode CCM/DCM operation at 90kHz/35kHz switching frequencies for industrial SMPS design validation.

For engineers reviewing the STEVAL-ISA007V1 datasheet, STEVAL-ISA007V1 pinout, STEVAL-ISA007V1 application, or STEVAL-ISA007V1 equivalent, this board enables rapid prototyping of wide-input (400Vac ±20%), high-voltage flyback auxiliary supplies targeting industrial motor drives, PLCs, and high-reliability power systems requiring robust 1500V blocking capability and secondary-side regulation.

Technical Context

The board implements a mixed-mode flyback converter using the L5991A PWM IC to dynamically switch between Continuous Conduction Mode (CCM) above 25W and Discontinuous Conduction Mode (DCM) below 25W, enabling stable loop control across wide load and input ranges while mitigating right-half-plane zero instability. It leverages the STC08DE150HV ESBT's 1500V V_CEO, 5A I_C, and TO-247-4L HV leads for high-voltage primary switching under 400Vac ±20% input.

Secondary regulation uses TL431AI shunt reference (2.5V, 1–100mA) with optocoupler feedback, supporting precise 24V and 5V outputs. Auxiliary 15V rail powers control circuitry, and ultrafast diodes (STTH102, STTH108, STTH3002CT) ensure low-loss rectification at 90kHz switching frequency.

Key Specifications

Availability

STEVAL-ISA007V1 is available at Aetrix Electronics and suitable for industrial motor drives, programmable logic controllers (PLCs), high-voltage power supply reference designs, and factory automation equipment requiring stable component supply and validated auxiliary SMPS architecture.

Supply support for STEVAL-ISA007V1 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 devices, analog ICs, and sensors for industrial, automotive, and consumer applications.

This evaluation board belongs to ST's STEVAL reference design series, developed specifically to accelerate adoption of high-voltage ESBT-based auxiliary power supplies in demanding industrial environments where reliability, wide-input tolerance, and mixed-mode control are critical.

FAQ

What is the primary purpose of the STEVAL-ISA007V1 evaluation board?

The STEVAL-ISA007V1 is a reference design board for validating high-power 3-phase auxiliary SMPS topologies. It demonstrates mixed-mode (CCM/DCM) flyback operation using the L5991A controller and STC08DE150HV ESBT, targeting industrial applications needing dual regulated outputs (24V/6.25A and 5V/75mA) from 400Vac ±20% input with >85% efficiency.

Can STEVAL-ISA007V1 be used with single-phase AC input?

No - the board is designed exclusively for 3-phase 400Vac ±20% input as specified in its schematic and layout. Its transformer, ESBT snubber network, and input rectifier stage are optimized for balanced 3-phase line-to-line voltage; single-phase use would cause overvoltage stress, incorrect duty cycle, and potential failure of the STC08DE150HV or L5991A.

Does STEVAL-ISA007V1 include built-in protection features?

Yes - it incorporates overvoltage protection via 1.5KE400A Transil (400V clamping), primary-side current limiting through L5991A's internal sensing, and thermal derating enabled by the STC08DE150HV's SOA-rated operation. However, no dedicated short-circuit or overload latch-off is implemented; protection relies on foldback behavior and external fuse coordination per application requirements.

Is firmware or software required to operate STEVAL-ISA007V1?

No - STEVAL-ISA007V1 is an analog hardware reference design with no microcontroller or programmable element. Operation is fully autonomous: the L5991A PWM controller manages mode switching, feedback regulation, and timing using discrete components and the TL431AI shunt reference. No configuration, code upload, or host interface is needed.