STMicroelectronics STEVAL-ISA099V1

Overview

STEVAL-ISA099V1 from STMicroelectronics is a step-down switching demonstration board based on the L7986 synchronous buck regulator in DFN10 package, delivering up to 3 A DC output current with input voltage range 4.5 V to 38 V, adjustable output from 0.6 V, and programmable switching frequency from 250 kHz to 1 MHz. It supports zero-load operation, internal soft-start, enable control, voltage feed-forward, and overcurrent/thermal protection - deployed for industrial power supply validation.

For engineers reviewing the STEVAL-ISA099V1 datasheet, STEVAL-ISA099V1 pinout, STEVAL-ISA099V1 application, or STEVAL-ISA099V1 equivalent, this board enables rapid evaluation of high-input-voltage buck regulation under real thermal and load-transient conditions, with emphasis on layout-sensitive high-current switching performance and external component minimization.

Technical Context

The board implements the L7986 IC - a monolithic synchronous step-down regulator integrating a 3.7 A minimum current-limited power MOSFET pair, supporting continuous 3 A output across wide input (4.5–38 V) and output (0.6 V to VIN) ranges. Its voltage feed-forward architecture improves transient response to input voltage changes.

Switching frequency is internally set to 250 kHz but externally programmable up to 1 MHz via resistor; internal soft-start prevents inrush current, while 100% duty-cycle low-dropout mode extends regulation at low VIN–VOUT differentials. Thermal shutdown and cycle-by-cycle overcurrent protection are hardware-enforced.

Key Specifications

Availability

STEVAL-ISA099V1 is available at Aetrix Electronics and suitable for industrial power supply validation, embedded system prototype testing, and high-input-voltage DC-DC converter design requiring stable component supply and documented reference layout.

Supply support for STEVAL-ISA099V1 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 silicon solutions for automotive, industrial, and consumer applications with focus on energy efficiency and system integration.

The STEVAL-ISA099V1 belongs to ST's power conversion evaluation board portfolio, developed specifically to accelerate adoption of high-voltage synchronous buck regulators in space-constrained, thermally demanding industrial and automation equipment.

FAQ

What input voltage sources are compatible with STEVAL-ISA099V1?

The board accepts DC input from 4.5 V to 38 V, making it compatible with standard 12 V and 24 V industrial power supplies, lead-acid or LiFePO₄ battery stacks, and regulated lab bench supplies. Input must be well-filtered and capable of sustaining ≥3.5 A peak current during transient loads.

Can the output voltage be set below 0.6 V?

No - the L7986's internal reference and error amplifier architecture limit the minimum regulated output to 0.6 V, as confirmed by the device's feedback divider equation and datasheet specification. Attempting lower outputs risks regulation loss and instability.

Does STEVAL-ISA099V1 include input reverse-polarity protection?

No - the board lacks integrated reverse-polarity or overvoltage protection circuitry. Users must add external TVS diodes or MOSFET-based protection if operating in environments with risk of incorrect connection or voltage surges.

Is the PCB layout optimized for EMI compliance?

Yes - the board follows ST's recommended high-current loop minimization, ground plane integrity, and thermal pad stitching practices per AN4405. Measured conducted emissions meet EN55022 Class B limits when used with proper input filtering and enclosure grounding.