STMicroelectronics STEVAL-1PS03A

Overview

STEVAL-1PS03A from STMicroelectronics is an evaluation board built around the ST1PS03AQTR nano-quiescent synchronous step-down converter, delivering up to 400 mA output current from 1.8–5.5 V input with digitally selectable 1.6–3.3 V output, Power Good signaling, and an integrated load switch for VIN_AUX rail control. It demonstrates ultra-compact power conversion using only a 2.2 µH inductor and two 10 µF capacitors.

For engineers reviewing the STEVAL-1PS03A datasheet, STEVAL-1PS03A pinout, STEVAL-1PS03A application, or STEVAL-1PS03A equivalent, this board enables rapid validation of low-power DC-DC conversion in space-constrained wearable and sensor systems where quiescent current, PCB area, and dynamic voltage selection are critical design constraints.

Technical Context

The board implements the ST1PS03AQTR IC in thin TQFN12 (2.0 × 1.7 mm) packaging, featuring enhanced peak current control (PCC) architecture for stable transient response and ultra-low quiescent current operation. Its digital voltage selection interface (D0/D1/D2) supports eight discrete output levels between 1.6 V and 3.3 V in 200 mV steps.

Integrated circuitry includes independent enable (EN), Power Good (PGOOD) monitoring at VOUT, and a controlled load switch driven by AUX input-allowing external subsystem power sequencing without additional discrete FETs or logic.

Key Specifications

Availability

STEVAL-1PS03A is available at Aetrix Electronics and suitable for wearable electronics development, Bluetooth® Low Energy sensor node prototyping, and industrial IoT edge device power validation requiring stable component supply and fast-turn evaluation support.

Supply support for STEVAL-1PS03A 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, designing and manufacturing microcontrollers, power management ICs, analog devices, and MEMS sensors for industrial, automotive, and consumer applications.

The STEVAL-1PS03A belongs to ST's ST1PS series of nano-quiescent DC-DC converters, engineered specifically for ultra-low-power battery-operated systems where extended runtime and minimal PCB footprint are primary design goals.

FAQ

What is the purpose of the AUX pin on the STEVAL-1PS03A board?

The AUX pin controls an integrated load switch that delivers VIN_AUX - a separate, unregulated power rail derived directly from the input supply. This allows independent power gating of auxiliary subsystems (e.g., sensors or RF modules) without requiring external MOSFETs or discrete switching logic, reducing component count and layout complexity.

How many output voltage levels can be selected on the STEVAL-1PS03A, and how are they set?

The board supports eight discrete output voltages from 1.6 V to 3.3 V in 200 mV increments, configured using the D0, D1, and D2 digital select inputs. These pins accept standard CMOS logic levels and map directly to the ST1PS03AQTR's internal DAC, enabling firmware-controlled rail adjustment without hardware modification.

Does the STEVAL-1PS03A include Power Good functionality, and how is it used?

Yes - the PGOOD pin asserts high when the main VOUT rail is within ±5% of its programmed value. This signal is routed to CN1 Pin 6 and can drive MCU reset inputs, interrupt lines, or status LEDs, providing deterministic power-up sequencing and fault detection in battery-powered applications.

What is the minimum external component count required to operate the ST1PS03AQTR on this board?

The ST1PS03AQTR requires only three external components for basic operation: a 2.2 µH power inductor (L1), one 10 µF input capacitor (C1), and one 10 µF output capacitor (C3). The board includes these plus optional decoupling and test points, but the core functional solution fits in under 10 mm² PCB area.