STMicroelectronics STEVAL-ISA091V1

Overview

STEVAL-ISA091V1 from STMicroelectronics is an evaluation board for the L7980 2 A step-down switching regulator, designed to demonstrate high-efficiency DC-DC conversion in compact industrial and consumer power supplies. It supports 4.5–28 V input, delivers up to 2 A at adjustable output voltages starting from 0.6 V, operates at 250 kHz (programmable up to 1 MHz), and features internal soft-start, overcurrent/thermal protection, and VFQFPN3x3-8L/HSOP8 package compatibility.

For engineers reviewing the STEVAL-ISA091V1 datasheet, STEVAL-ISA091V1 pinout, STEVAL-ISA091V1 application, or STEVAL-ISA091V1 equivalent, this board enables rapid validation of L7980-based buck converter designs-especially for FPGA core supply, LCD TV bias rails, and industrial PLC I/O power-under real thermal and transient load conditions with minimal external components.

Technical Context

The STEVAL-ISA091V1 implements the L7980 IC in voltage-mode PWM control with feed-forward compensation, supporting both fixed-frequency operation and external synchronization via the SYNCH pin. Its layout integrates a low-ESR ceramic input capacitor, shielded power inductor, and optimized thermal pad routing for VFQFPN and HSOP packages.

It validates key L7980 behaviors: zero-load current operation, 100% duty-cycle low-dropout mode, hiccup-mode overcurrent protection during regulation, and soft-start ramping (7.4–9.1 ms) synchronized to switching frequency-enabling accurate loop stability analysis using Type II or Type III compensation networks.

Key Specifications

Availability

STEVAL-ISA091V1 is available at Aetrix Electronics and suitable for FPGA core voltage regulation, LCD TV backlight power supplies, and industrial PLC I/O module power conversion requiring stable component supply, fast prototyping turnaround, and production-ready thermal performance validation.

Supply support for STEVAL-ISA091V1 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 specializing in power management, microcontrollers, and analog ICs, with manufacturing and R&D centers across Europe, Asia, and the Americas.

The STEVAL-ISA091V1 belongs to ST's STEVAL evaluation platform family, engineered to accelerate adoption of its high-efficiency DC-DC regulators-specifically targeting space-constrained, thermally demanding applications in consumer electronics and industrial automation.

FAQ

Does STEVAL-ISA091V1 support both VFQFPN and HSOP8 package variants of the L7980?

Yes. The board provides footprint options and layout provisions for both the VFQFPN3x3-8L and HSOP8 packages of the L7980, including dedicated thermal pad vias and copper pour areas calibrated to achieve R_thJA values of 60 °C/W and 40 °C/W respectively-matching the datasheet thermal specifications for each package.

Can the switching frequency be synchronized to an external clock source using this evaluation board?

Yes. The STEVAL-ISA091V1 exposes the SYNCH pin of the L7980, allowing direct connection to an external master clock signal. When driven with a frequency higher than the internal oscillator (250 kHz), the device synchronizes with zero phase shift-enabling multi-phase interleaving and EMI reduction in systems with multiple L7980-based rails.

What is the minimum output voltage achievable with this board, and how is it set?

The board supports output voltages as low as 0.6 V, set by connecting the FB pin directly to the output. For higher outputs, an external resistor divider (R1/R2) is used per the formula V_OUT = 0.6 V × (1 + R1/R2); the board includes test points and solder jumpers to facilitate quick ratio changes and precision trimming during validation.

Is the STEVAL-ISA091V1 RoHS-compliant and qualified for industrial temperature operation?

Yes. The board uses only RoHS-compliant components and PCB materials, and is validated across –40 °C to +125 °C ambient per the L7980's full industrial temperature range. Thermal imaging and load testing confirm stable 2 A operation at 85 °C ambient with no derating required.