STMicroelectronics ST1PS01DJR

Overview

ST1PS01DJR from STMicroelectronics is a nano-quiescent (500 nA), synchronous step-down DC-DC converter in Flip-Chip8 package, delivering up to 400 mA output current with 1.8–5.5 V input range and digitally selectable output voltages (1.8 V / 2.3 V / 2.5 V / 2.8 V). It integrates Power Good flag, 100% duty cycle operation, and soft-start for ultra-low-power wearable systems powered by single-cell Li-ion batteries.

For engineers reviewing the ST1PS01DJR datasheet, ST1PS01DJR pinout, ST1PS01DJR application, or ST1PS01DJR equivalent, key selection criteria include quiescent current at light load, dynamic voltage scaling capability via D0/D1 pins, PGOOD threshold accuracy (±2.5% hysteresis), and thermal resistance (60 °C/W) in the 1.14×1.44 mm Flip-Chip8 footprint.

Technical Context

The ST1PS01DJR employs peak current control (PCC) architecture with seamless PFM/PWM mode transition to maintain high efficiency across microampere-to-milliamperes loads. Its hysteretic comparator senses coil ripple current-held constant across all operating modes-to enable stable regulation without external compensation.

It features integrated 100% duty cycle mode (activated when VIN ≤ VOUT + 300 mV), fast output discharge during shutdown, and UVLO with 1.57 V falling threshold and 65 mV hysteresis. The digital voltage selection logic directly maps D0/D1 states to four fixed VOUT values without resistor dividers.

Key Specifications

Pinout & Package

ST1PS01DJR uses the Flip-Chip8 package (1.14 × 1.44 mm, 0.5 mm pitch), optimized for minimal PCB area and thickness in space-constrained wearables. Bump-level interconnects eliminate wire bonds and reduce parasitic inductance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS62840YKAR and ADP5302ACBZ-1-R7, ST1PS01DJR uniquely combines nano-IQ, four factory-programmed VOUT options, integrated PGOOD, and 100% duty cycle - making it optimal for compact, multi-rail, battery-critical wearables where firmware-controlled voltage scaling adds system-level power savings.

Availability

ST1PS01DJR is available at Aetrix Electronics and suitable for wearable sensors, BLE beacons, and energy-harvesting nodes requiring stable component supply, long-term lifecycle support, and guaranteed traceability for medical and industrial certifications.

Supply support for ST1PS01DJR 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, sensors, and analog devices for automotive, industrial, and consumer markets.

The ST1PS01 series targets ultra-low-power portable electronics, specifically engineered to replace linear regulators and legacy buck converters in space- and battery-limited applications where efficiency below 10 µA load is decisive.

FAQ

What is the minimum input voltage required for ST1PS01DJR to start switching?

The device enters undervoltage lockout (UVLO) when VIN falls below 1.57 V (typical, falling threshold). Switching resumes only after VIN rises above 1.63 V (typical, rising threshold), providing 65 mV hysteresis to prevent oscillation near the cutoff point. This ensures reliable cold-start from partially discharged single-cell Li-ion batteries down to 2.5 V nominal.

Can ST1PS01DJR dynamically change output voltage while powered?

Yes - D0 and D1 pins support real-time VOUT reconfiguration during operation. However, valid transitions require VIN ≥ selected VOUT + 300 mV to ensure stable regulation. For example, switching from 1.8 V to 2.8 V is permitted only if VIN ≥ 3.1 V; the device will hold last valid output until input condition is met.

How does the 100% duty cycle mode affect output voltage regulation?

In 100% mode, the high-side MOSFET remains continuously on, connecting VIN directly to VOUT through the inductor and internal R_DS(on). Output voltage equals VIN minus conduction losses (typically <100 mV at 100 mA), eliminating switching losses but forfeiting regulation. The device automatically exits this mode when VIN exceeds VOUT + 300 mV.

What external components are mandatory for basic ST1PS01DJR operation?

Mandatory components are: 10 µF input capacitor (CIN) at VIN, 10 µF output capacitor (COUT) at VOUT, 2.2 µH inductor between SW and VOUT, and a 1 MΩ pull-up resistor on PGOOD. EN must be tied high or controlled by a GPIO; D0/D1 require defined logic levels - floating pins cause undefined VOUT and potential instability.