STMicroelectronics STEVAL-ISA068V1

Overview

STEVAL-ISA068V1 from STMicroelectronics is an evaluation board for the ST1S32 4 A synchronous step-down DC-DC regulator, designed to demonstrate high-efficiency point-of-load conversion with adjustable output voltage (0.8 V to VIN), 1.5 MHz switching frequency, and integrated 60 mΩ/45 mΩ MOSFETs in VFDFPN-8 package. It supports µP/DSP/FPGA core and I/O supplies in STB, TV, and optical storage systems.

For engineers reviewing the STEVAL-ISA068V1 datasheet, STEVAL-ISA068V1 pinout, STEVAL-ISA068V1 application, or STEVAL-ISA068V1 equivalent, this board enables rapid validation of ST1S32 performance under real-world load transients, thermal stress, and layout-sensitive high-frequency operation - critical for embedded power design in consumer and industrial edge devices.

Technical Context

The STEVAL-ISA068V1 implements the ST1S32's peak-current-mode control architecture with internal compensation, enabling stable regulation across 2.8–5.5 V input and 0.8 V–VIN output while supporting ceramic-only external components. Its PCB layout follows ST's recommended thermal pad grounding, input/output capacitor placement, and SW node minimization guidelines.

It integrates a 1.0 µH shielded inductor, 47 µF MLCC output capacitor, and resistor divider (R1=10 kΩ, R2=20 kΩ) configured for 1.2 V output - matching the reference design validated for 117 kHz bandwidth and 63° phase margin per ST's small-signal analysis.

Key Specifications

Availability

STEVAL-ISA068V1 is available at Aetrix Electronics and suitable for FPGA power delivery, STB power management, and optical drive subsystem design requiring stable component supply and pre-validated thermal performance.

Supply support for STEVAL-ISA068V1 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 over 40 years of automotive- and industrial-grade design heritage.

The STEVAL-ISA068V1 belongs to ST's STEVAL evaluation board family, engineered specifically to accelerate adoption of their high-efficiency DC-DC regulators in space-constrained, thermally demanding consumer and computing applications.

FAQ

What input voltage range does the STEVAL-ISA068V1 support?

The board operates from 2.8 V to 5.5 V DC input, aligned with the ST1S32 regulator's specification. It is optimized for single-rail 3.3 V or 5 V sources and includes reverse-polarity protection on the input connector. Input ripple is suppressed using a 10 µF/25 V MLCC and 330 nF bypass capacitor placed adjacent to VINA and VINSW pins.

Can the output voltage be adjusted, and how?

Yes - the output is set to 1.2 V by default using a 10 kΩ/20 kΩ resistor divider from VOUT to FB, but it is fully adjustable from 0.8 V to VIN by modifying R1 and R2 values. The feedback threshold is precisely 0.8 V ±2%, and the board provides test points for FB, PG, and EN signals to support dynamic reconfiguration.

Does the board include thermal management features?

Yes - the PCB uses a 2-layer copper pour under the ST1S32's exposed thermal pad (connected to PGND), with 8 thermal vias to inner ground planes. Measured thermal resistance from junction to ambient is 40 °C/W when mounted on the demo board, enabling 4 A operation up to +60 °C ambient without forced airflow.

Is Power Good (PG) functionality accessible on the board?

Yes - the open-drain PG signal is routed to a test point and can be monitored directly. It asserts high-Z when VOUT exceeds 92% of target (e.g., >1.104 V for 1.2 V output) after a 170 µs delay, and pulls low during undervoltage or fault conditions. A 10 kΩ pull-up resistor is included for immediate logic-level interfacing.