STMicroelectronics STEVAL-ISA107V1

Overview

STEVAL-ISA107V1 from STMicroelectronics is an evaluation board for the ST1S41PHR synchronous step-down DC-DC converter, configured as a fixed-frequency 850 kHz PWM regulator delivering up to 4 A output current. It supports 4.0–18 V input, adjustable 0.8 V–VIN output, and integrates 95 mΩ high-side and 69 mΩ low-side Power MOSFETs in SO-8 ePad package.

For engineers reviewing the STEVAL-ISA107V1 datasheet, STEVAL-ISA107V1 application schematic, STEVAL-ISA107V1 bill of materials, or STEVAL-ISA107V1 design files, this board enables rapid validation of ST1S41-based compact, all-ceramic, internally compensated buck converters in industrial power supplies, point-of-load regulators, and embedded system rails.

Technical Context

The STEVAL-ISA107V1 implements peak-current-mode control with internal compensation, eliminating external loop compensation components. Its fixed 850 kHz switching frequency enables small external inductors and ceramic capacitors while maintaining stable regulation across 4.0–18 V input range.

It incorporates cycle-by-cycle current limiting and current-foldback short-circuit protection, with enable functionality and internal soft-start to prevent inrush current. The board uses only ceramic output capacitors and supports 100% duty cycle for VIN-referenced output operation.

Key Specifications

Availability

STEVAL-ISA107V1 is available at Aetrix Electronics and suitable for industrial power supply validation, point-of-load (POL) converter prototyping, and embedded system voltage rail development requiring stable component supply and documented reference design support.

Supply support for STEVAL-ISA107V1 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 designing and manufacturing microcontrollers, analog ICs, power management devices, and MEMS sensors for industrial, automotive, and consumer applications.

The STEVAL-ISA107V1 belongs to ST's ST1S series of monolithic synchronous buck converters, engineered for space-constrained, high-efficiency DC-DC conversion in cost-sensitive industrial and computing systems.

FAQ

What is the purpose of the STEVAL-ISA107V1 evaluation board?

The STEVAL-ISA107V1 is a fully assembled and tested reference design board for the ST1S41PHR synchronous step-down converter. It provides a ready-to-use platform to evaluate electrical performance, thermal behavior, and PCB layout practices-including all-ceramic capacitor implementation and SO-8 ePad thermal management-without requiring custom design effort.

Does the board support adjustable output voltage, and how is it set?

Yes, the output voltage is adjustable from 0.8 V to VIN using an external resistor divider network connected to the FB pin. The board includes solder jumpers and footprint options to configure common outputs such as 1.2 V, 1.8 V, 2.5 V, 3.3 V, and 5.0 V, with full adjustment range accessible via test points.

Can the STEVAL-ISA107V1 operate with 100% duty cycle, and under what conditions?

Yes, the ST1S41 controller on this board supports 100% duty cycle operation when the feedback voltage drops below the internal 0.8 V reference, enabling output voltages equal to VIN minus small dropout losses. This mode is active during startup or low-load conditions where regulation is not required, improving light-load efficiency.

Is the board RoHS compliant and suitable for commercial-grade applications?

Yes, the STEVAL-ISA107V1 is RoHS compliant per its official data brief (DocID025266 Rev 1). It is intended for commercial and industrial applications-not safety-critical, automotive, or aerospace use-as explicitly stated in ST's disclaimer. No ST qualification (e.g., AEC-Q100, ESCC) applies to this evaluation board.