STMicroelectronics STEVAL-ISA192V1

Overview

STEVAL-ISA192V1 from STMicroelectronics is a 7 W dual-output flyback evaluation board implementing zero-power mode (ZPM) standby control via capacitive touch and push buttons, using VIPer0P (800 V avalanche-rugged PWM controller) and STM32L052K6 microcontroller. It delivers +7 V @ 400 mA and −5 V @ 800 mA across 85–265 VAC input, achieves <30 mW input power at 230 VAC in ZPM, and complies with IEC61000-4-2/4/5 and IEC55022 Class B EMI standards.

For engineers reviewing the STEVAL-ISA192V1 datasheet, STEVAL-ISA192V1 pinout, STEVAL-ISA192V1 application, or STEVAL-ISA192V1 equivalent, this board supports rapid validation of ultra-low-standby-capable offline SMPS designs with integrated capacitive touch wake-up, ZPM sequencing, and dual-rail output regulation for smart appliances and IoT edge devices.

Technical Context

The board implements a non-isolated flyback topology with fixed 60 kHz switching frequency and soft-start functionality. ZPM entry requires OFF pin held low to SGND for >10 ms; exit requires ON pin pulled low for >20 μs - both triggered by tactile switches or MCU-driven signals.

VIPer0P provides embedded protections including overload/short-circuit auto-restart, thermal shutdown, VCC clamp, pulse-skip flux runaway prevention, and 800 V avalanche ruggedness. The STM32L052K6 manages touch sensing, ZPM state transitions, and LDO enable control while consuming minimal current during polling.

Key Specifications

Availability

STEVAL-ISA192V1 is available at Aetrix Electronics and suitable for smart home appliance control units, IoT gateway power supplies, energy-efficient industrial HMI panels, and battery-less capacitive-touch-enabled consumer electronics requiring stable component supply and rapid ZPM validation.

Supply support for STEVAL-ISA192V1 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, sensors, and analog components for industrial, automotive, and consumer applications.

This board belongs to ST's STEVAL (ST Evaluation) series, engineered to accelerate development of energy-efficient offline SMPS with intelligent standby features - specifically targeting regulatory-compliant, touch-activated low-power systems.

FAQ

What is the role of the STM32L052K6 on STEVAL-ISA192V1?

The STM32L052K6 microcontroller detects capacitive touch and push-button events, controls VIPer0P's ON/OFF pins to enter or exit zero-power mode, manages firmware-level polling strategy for ultra-low standby current, and drives status indicators. Its ultra-low-power architecture enables sustained ZPM operation without compromising wake-up responsiveness.

How is the −5 V output generated without a separate winding?

The −5 V output is derived by referencing EAGND to the negative rail and using a resistor divider between FB, EAGND, and SGND to set the feedback voltage. This leverages the flyback transformer's inherent polarity inversion and eliminates need for an extra secondary winding or charge-pump circuit.

Can STEVAL-ISA192V1 be used without modifying hardware for ZPM testing?

Yes - tactile switches S1 (ENTER-ZPM) and S2 (EXIT-ZPM) are pre-mounted and directly connected to VIPer0P's OFF and ON pins. No soldering or jumper configuration is required; pressing S1 for >10 ms initiates ZPM, and pressing S2 for >20 μs resumes normal operation - enabling immediate functional validation.

What protection features does VIPer0P provide on this board?

VIPer0P delivers auto-restart overload/short-circuit protection, maximum duty-cycle limiting, VCC overvoltage clamping, thermal shutdown, and pulse-skip flux runaway prevention. These are hardware-enforced, cycle-by-cycle functions independent of MCU supervision - ensuring robust fault recovery even during firmware hangs or brownouts.