STMicroelectronics STEVAL-1PS02B

Overview

STEVAL-1PS02B from STMicroelectronics is an evaluation board for the ST1PS02BQTR nano-quiescent synchronous step-down converter, demonstrating dynamic 1.8 V–2.5 V output voltage selection, Power Good signaling, and auxiliary load switching (VOUT2) in a compact layout. It delivers up to 400 mA from 1.8 V–5.5 V input using only a 2.2 µH inductor and two small capacitors, targeting ultra-low-power wearable and sensor applications.

For engineers reviewing the STEVAL-1PS02B datasheet, STEVAL-1PS02B pinout, STEVAL-1PS02B application, or STEVAL-1PS02B equivalent, this board enables rapid validation of ST1PS02BQTR's low-I_Q buck conversion, digital voltage selection timing, AUX switch sequencing, and Power Good assertion behavior in single-cell Li-ion and energy-harvesting systems.

Technical Context

The STEVAL-1PS02B implements a complete reference design around the ST1PS02BQTR, a TQFN12-packaged 400 mA synchronous buck converter with enhanced peak current control (PCC) architecture and <1.5 µA quiescent current. It integrates a controlled auxiliary load switch (VOUT2) driven by an independent AUX input, enabling subsystem power gating synchronized with main rail regulation.

Board-level features include dedicated test points (TP1), configurable jumpers (JP1, JP2), dual output rails (VOUT and VOUT2), and header interfaces (CN1–CN8) for VIN, GND, EN, PGOOD, and AUX control-supporting both functional verification and integration into host systems requiring precise low-power sequencing.

Key Specifications

Availability

STEVAL-1PS02B is available at Aetrix Electronics and suitable for wearable electronics development, industrial wireless sensor node prototyping, and Bluetooth® Low Energy subsystem validation requiring stable component supply and documented reference design fidelity.

Supply support for STEVAL-1PS02B 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, specializing in microcontrollers, power management ICs, sensors, and automotive-grade solutions.

The STEVAL-1PS02B belongs to ST's power management evaluation board portfolio, designed specifically to accelerate adoption of ultra-low-quiescent-current DC-DC converters in battery-constrained IoT edge devices.

FAQ

What is the primary function of the AUX switch on STEVAL-1PS02B?

The AUX switch controls the VOUT2 rail independently via the AUX input signal, allowing external logic (e.g., MCU GPIO) to gate power to peripherals like RF modules or sensors. It is not a pass-through switch but a controlled load switch integrated into the ST1PS02BQTR, rated for ≤400 mA and synchronized with main rail startup timing.

Can STEVAL-1PS02B operate from a 1.8 V input while delivering 2.5 V output?

No - the ST1PS02BQTR is a step-down converter only; it cannot boost voltage. At 1.8 V input, maximum regulated output is 1.8 V (subject to dropout). The 1.8 V–2.5 V output range requires input ≥2.5 V + dropout (typically ≥2.7 V), as confirmed in DB4160 Section 5.1.

Is the PGOOD signal actively driven or open-drain?

The PGOOD signal is an open-drain output requiring an external pull-up resistor (R2 on board). It asserts low when VOUT is within ±3% of target and remains low for ≥100 µs after regulation is achieved, per ST1PS02BQTR datasheet Section 8.3.

Does STEVAL-1PS02B support adjustable switching frequency?

No - the ST1PS02BQTR uses fixed-frequency operation at 2.2 MHz (typical), with no external frequency programming pins or resistor options. This simplifies EMI filtering and reduces component count, as verified in DB4160 electrical characteristics table.