STMicroelectronics STEVAL-ISA108V1

Overview

STEVAL-ISA108V1 from STMicroelectronics is a 4 A, 850 kHz fixed-frequency PWM synchronous step-down demonstration board based on the ST1S41 regulator in VFQFPN package. It supports 4–18 V input, delivers adjustable output down to 0.8 V, integrates 95 mΩ high-side and 69 mΩ low-side MOSFETs, features internal soft-start and cycle-by-cycle current limiting, and is used for evaluating high-efficiency low-voltage DC/DC conversion in industrial power supplies.

For engineers reviewing the STEVAL-ISA108V1 datasheet, STEVAL-ISA108V1 pinout, STEVAL-ISA108V1 application, or STEVAL-ISA108V1 equivalent, key selection considerations include input voltage range (4–18 V), output adjustability (0.8 V min), switching frequency (850 kHz), ceramic-capacitor compatibility, and integrated current-limiting protection for rapid prototyping of compact buck converters.

Technical Context

The board implements peak-current-mode control with internal compensation, eliminating external loop compensation components. The ST1S41 IC provides fixed 850 kHz PWM operation, enabling small external inductors and capacitors while maintaining stable regulation across load transients.

It integrates both power switches - a 95 mΩ high-side MOSFET and 69 mΩ synchronous rectifier - supporting up to 4 A continuous output current with high efficiency at low output voltages (e.g., 1.2 V, 0.8 V). Current fold-back short-circuit protection and enable functionality are implemented directly on the board.

Key Specifications

Availability

STEVAL-ISA108V1 is available at Aetrix Electronics and suitable for industrial power supply evaluation, FPGA/ASIC core rail development, and embedded system DC/DC converter validation requiring stable component supply and documented reference design fidelity.

Supply support for STEVAL-ISA108V1 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 analog, MCU, power, and sensor solutions for industrial, automotive, and consumer markets.

The STEVAL-ISA108V1 belongs to ST's STEVAL demonstration board family, engineered to accelerate evaluation and adoption of ST's integrated power regulators-specifically targeting rapid validation of synchronous buck topologies in space-constrained, efficiency-critical applications.

FAQ

What is the purpose of the STEVAL-ISA108V1 board?

The STEVAL-ISA108V1 is a ready-to-use demonstration board for the ST1S41 synchronous step-down regulator. It enables immediate evaluation of 4 A, 850 kHz buck conversion with adjustable 0.8 V output, internal compensation, and full protection features-without requiring custom PCB design or component selection.

Does the board support adjustable output voltage?

Yes. The output voltage is set via an external resistor divider connected to the FB pin of the ST1S41. The board includes footprint and routing for the divider, allowing adjustment from 0.8 V up to the input voltage (100% duty cycle), verified per ST's application schematic and data brief.

Can the STEVAL-ISA108V1 be used for thermal testing?

Yes. The board uses a thermally optimized layout with exposed pad soldered to PCB copper, matching the VFQFPN-16 package thermal requirements of the ST1S41. Measured thermal performance supports 4 A continuous operation at ambient ≤50 °C with minimal heatsinking, as confirmed in ST's demo board documentation.

Is the board RoHS compliant and lead-free?

Yes. The STEVAL-ISA108V1 is explicitly stated as RoHS compliant in its official STMicroelectronics data brief (Doc ID 024148 Rev 1), and all bill-of-materials components-including the ST1S41 IC, inductors, and ceramic capacitors-are manufactured to RoHS and lead-free standards per ST's compliance declarations.