STMicroelectronics STEVAL-ISA069V1

Overview

STEVAL-ISA069V1 from STMicroelectronics is an evaluation board designed to demonstrate the ST1S31 3 A synchronous step-down DC-DC regulator in VFDFPN 3 × 3 – 8L package. It delivers adjustable output voltage from 0.8 V to VIN, supports 2.8–5.5 V input, operates at 1.5 MHz, and integrates 60 mΩ high-side and 45 mΩ low-side MOSFETs for high-efficiency point-of-load conversion in FPGA core supplies and consumer electronics.

For engineers reviewing the STEVAL-ISA069V1 datasheet, STEVAL-ISA069V1 pinout, STEVAL-ISA069V1 application, or STEVAL-ISA069V1 equivalent, this board enables rapid validation of ST1S31 performance under real-world load transients, thermal stress, and layout-sensitive switching conditions - especially for µP/ASIC I/O rail design and STB/TV power delivery.

Technical Context

The STEVAL-ISA069V1 implements the ST1S31's peak-current-mode PWM control architecture with internal slope compensation, fixed 1.5 MHz switching frequency, and integrated soft-start. It uses all-ceramic passive components and supports output voltage adjustment via external resistor divider on the FB pin referenced to 0.8 V.

Board-level protection includes cycle-by-cycle current limiting, current foldback short-circuit response, and hysteretic thermal shutdown (150 °C trip, 130 °C recovery). The PG (Power Good) open-drain signal asserts after 170 µs when VOUT exceeds 92% of regulation target.

Key Specifications

Availability

STEVAL-ISA069V1 is available at Aetrix Electronics and suitable for FPGA core supply validation, STB/TV point-of-load design, and optical storage power subsystem development requiring stable component supply and full production-ready reference implementation.

Supply support for STEVAL-ISA069V1 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, Switzerland, specializing in power management, microcontrollers, analog ICs, and automotive-grade silicon.

The STEVAL-ISA069V1 belongs to ST's STEVAL evaluation board family, engineered to accelerate adoption of ST's high-efficiency DC-DC regulators in consumer, computing, and industrial power applications.

FAQ

What input voltage range does the STEVAL-ISA069V1 support?

The board accepts 2.8 V to 5.5 V DC input, matching the ST1S31's operational range. It is optimized for use with standard 3.3 V or 5 V system rails and single-cell Li-ion sources. Input capacitors are rated for 6.3 V ceramic types, and the layout minimizes parasitic inductance between VIN_SW and CIN.

How is output voltage adjusted on this evaluation board?

Output voltage is set using an external resistor divider from VOUT to the FB pin, leveraging the ST1S31's 0.8 V internal reference. Default configuration delivers 1.2 V (R1 = 10 kΩ, R2 = 20 kΩ); changing R1/R2 allows precise tuning down to 0.8 V or up to VIN, with stability maintained across 10 mA–3 A loads.

Does the board implement thermal protection and fault reporting?

Yes - the ST1S31 IC on the board features hysteretic thermal shutdown (150 °C trip, ~130 °C recovery) and open-drain Power Good (PG) signaling. PG asserts after 170 µs when VOUT reaches ≥92% of target; it pulls low immediately if regulation is lost, enabling system-level fault detection and sequencing.

Can the STEVAL-ISA069V1 be used for light-load efficiency testing?

Yes - the ST1S31 enters frequency reduction mode below ~100 mA load, disabling high-side switching to minimize gate and switching losses. This behavior is fully observable on the board via SW node probing and confirms diode-emulation operation enabled by the low-side current sense circuitry.