STMicroelectronics STEVAL-ISA097V1

Overview

STEVAL-ISA097V1 from STMicroelectronics is a step-down switching demonstration board based on the L7985 synchronous buck regulator in DFN10 package, delivering up to 2 A 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 implements internal soft-start, enable control, voltage feed-forward, and zero-load operation for industrial power supply evaluation.

For engineers reviewing the STEVAL-ISA097V1 datasheet, STEVAL-ISA097V1 pinout, STEVAL-ISA097V1 application, or STEVAL-ISA097V1 equivalent, this board enables rapid validation of wide-input-voltage DC/DC conversion in space-constrained designs requiring thermal robustness, overcurrent protection, and adjustable regulation.

Technical Context

The board implements a non-isolated synchronous buck topology using the L7985 IC, which integrates a 2.5 A current-limited Power MOSFET and internal oscillator. Voltage feed-forward compensation ensures stable regulation across wide VIN variations, while 100% duty-cycle capability supports low-dropout operation near minimum input-output differential.

Internal soft-start limits inrush current during startup; thermal shutdown and cycle-by-cycle overcurrent protection safeguard under fault conditions. Zero-load current operation enables standby-mode compatibility in always-on systems without external bias circuitry.

Key Specifications

Availability

STEVAL-ISA097V1 is available at Aetrix Electronics and suitable for industrial power supply validation, automotive body electronics prototyping, and embedded system DC/DC subsystem integration requiring stable component supply and documented reference design traceability.

Supply support for STEVAL-ISA097V1 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 microcontrollers, analog ICs, power management devices, and MEMS sensors for industrial, automotive, and consumer applications.

The STEVAL-ISA097V1 belongs to ST's STEVAL evaluation board series, engineered to accelerate adoption of its high-voltage buck regulators in rugged, wide-input applications such as factory automation, smart meters, and transportation electronics.

FAQ

What is the maximum recommended output current for sustained operation on STEVAL-ISA097V1?

The board is validated for up to 2 A continuous output current under typical ambient conditions (25 °C, 200 LFM airflow) with the L7985's internal 2.5 A current limit and DFN10 thermal performance. Derating is required above 60 °C ambient or with reduced airflow; full 2 A operation assumes proper PCB copper pour and heatsinking per ST's layout guidelines in Doc ID 023076.

Can the output voltage be set below 0.6 V using external components?

No - the L7985's internal reference is fixed at 0.6 V, and the feedback network is designed for resistive division only. Output voltages below 0.6 V are not supported; attempting lower settings risks regulation loss or instability due to reference architecture constraints confirmed in the device's electrical characteristics table.

Does STEVAL-ISA097V1 support synchronization to an external clock signal?

No - the L7985 does not include an external sync input pin. Switching frequency is set either by the internal 250 kHz oscillator or by an external resistor (RT) to adjust up to 1 MHz; no provision exists for external clock injection or phase alignment per the functional block diagram and pinout in Doc ID 023076 Rev 1.

Is thermal pad soldering required for reliable operation?

Yes - the L7985 in DFN10 package requires the exposed thermal pad to be soldered to a dedicated PCB copper pour connected to GND. Omitting thermal pad connection causes junction temperature to exceed 150 °C at 1.5 A load, triggering thermal shutdown; ST's layout recommendations mandate ≥ 120 mm² thermal pad area with ≥ 4 thermal vias to inner ground planes.