STMicroelectronics ST1PS02D1QTR

Overview

ST1PS02D1QTR from STMicroelectronics is a nano-quiescent (500 nA), synchronous step-down DC-DC converter in TQFN12 package, delivering up to 400 mA output current with 1.0 V–1.35 V digitally selectable output voltage, 92% efficiency at 10 mA (VIN=3.6 V/VOUT=2.5 V), and integrated Power Good flag - designed for ultra-low-power wearable sensors powered by single-cell Li-ion batteries.

For engineers reviewing the ST1PS02D1QTR datasheet, ST1PS02D1QTR pinout, ST1PS02D1QTR application, or ST1PS02D1QTR equivalent, this device supports dynamic voltage scaling via D0/D1/D2 pins, embeds an auxiliary load switch (Vout2), features 100% duty cycle operation near VIN ≈ VOUT, and includes programmable current limiting via CL pin - critical for energy-harvesting and Bluetooth® Low Energy subsystems.

Technical Context

The ST1PS02D1QTR employs peak current control (PCC) architecture with seamless PFM/PWM mode transition, enabling stable regulation down to microampere loads while maintaining low output ripple. Its hysteretic comparator senses coil ripple current directly, eliminating need for external compensation.

It integrates dual regulation paths: main VOUT regulated via feedback from VOUT pin with ±1.5% accuracy at 25 °C, and auxiliary Vout2 controlled by AUX pin with 100 mA max load and 0.5–0.95 Ω on-resistance. UVLO (1.57 V falling threshold) and embedded soft-start (1.7 ms typical) ensure robust startup under weak-source conditions.

Key Specifications

Pinout & Package

TQFN12 package (2.0 mm × 1.7 mm × 0.55 mm), thermally enhanced with exposed pad, optimized for space-constrained wearables and PCB thickness-sensitive designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar nano-power synchronous buck converter applications.

Compared with TPS62840YKAR and ADP5302ACBZ-1-R7, ST1PS02D1QTR uniquely combines nano-quiescent operation, digital VOUT selection, integrated PGOOD, and auxiliary load switching - making it optimal for multi-rail, dynamically scaled, battery-constrained wearables where board area and BOM simplicity are critical.

Availability

ST1PS02D1QTR is available at Aetrix Electronics and suitable for wearable fitness monitors, Bluetooth® Low Energy sensor nodes, and energy-harvesting wireless devices requiring stable component supply with guaranteed long-term lifecycle support.

Supply support for ST1PS02D1QTR 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 power management, microcontrollers, and analog ICs for industrial, automotive, and consumer markets.

The ST1PS02 series belongs to ST's nano-power DC-DC converter product line, engineered specifically for space- and energy-constrained portable electronics where minimal quiescent current, tiny external components, and digital configurability are mandatory.

FAQ

What is the minimum input voltage required for ST1PS02D1QTR to start regulation?

The device enters regulation when VIN rises above the undervoltage lockout (UVLO) threshold of 1.63 V (typical). Below 1.57 V (falling), it shuts down and activates output discharge. This ensures reliable startup from partially discharged single-cell Li-ion batteries while preventing erratic behavior near cutoff.

Can ST1PS02D1QTR operate with a 1.0 V output while powered from a 1.8 V input?

Yes - ST1PS02D1QTR supports 1.0 V output (D2=1, D1=1, D0=0) with 1.8 V input. Its 100% duty cycle mode engages when VIN approaches VOUT + ~200 mV, allowing direct conduction through the high-side MOSFET to sustain output during deep battery discharge, with typical dropout <300 mV.

How does the CL pin affect current limiting, and what resistor value sets 300 mA limit?

The CL pin sets high-side MOSFET current limit: grounding CL yields 850 mA (typical); adding a pull-down resistor lowers it. For ~300 mA, a 1.5 MΩ resistor is required (per Table 6: ILIM3 = 250 mA typ. at 2.2 MΩ, 360 mA max. at 1 MΩ). This protects small inductors and PCB traces during fault conditions.

Is the Vout2 auxiliary output internally regulated, or does it track VOUT?

Vout2 is not independently regulated - it delivers the same nominal voltage as VOUT, reduced only by the on-resistance drop (RAUX = 0.5–0.95 Ω) of the integrated load switch. When AUX is high and IOUT2 = 100 mA, Vout2 ≈ VOUT − 75 mV (typ.), making it suitable for non-critical subsystems sharing the same rail.