STMicroelectronics ST1PS01BJR

Overview

ST1PS01BJR from STMicroelectronics is a nano-quiescent synchronous step-down DC-DC converter in Flip-Chip8 package, delivering up to 400 mA output current with 500 nA quiescent current at 3.6 V input and ±1.5% output voltage accuracy. It supports dynamic digital voltage selection (1.1 V / 1.2 V / 1.5 V / 1.7 V) via D0/D1 pins and features Power Good open-drain output. Designed for ultra-low-power wearable and energy-harvesting systems powered by single-cell Li-ion batteries.

For engineers reviewing the ST1PS01BJR datasheet, ST1PS01BJR pinout, ST1PS01BJR application, or ST1PS01BJR equivalent, key selection criteria include its 1.8–5.5 V input range, 100% duty cycle capability near V_OUT, embedded soft-start, undervoltage lockout (1.57 V falling), and minimal external component count (2.2 µH inductor + two 10 µF ceramic caps).

Technical Context

The ST1PS01BJR implements peak current control (PCC) with seamless PFM/PWM mode transition to maintain high efficiency across microampere-to-milliamperes loads. Its hysteretic comparator senses coil ripple current, enabling constant ripple regulation independent of load or input voltage.

It integrates a fast output discharge MOSFET (30 Ω on-resistance), UVLO with 65 mV hysteresis, and a fixed 1.7 ms startup delay. The 100% duty cycle mode activates when VIN ≤ V_OUT + 200 mV (falling), directly connecting VIN to VOUT through the high-side MOSFET while maintaining regulation integrity.

Key Specifications

Pinout & Package

ST1PS01BJR uses the Flip-Chip8 package (1.14 × 1.44 mm, 0.5 mm pitch), optimized for ultra-thin wearable PCBs with bottom-side bump interconnects and minimal footprint.

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, ST1PS01BJR uniquely combines digital VOUT selection, PGOOD, 100% duty cycle, and 400 mA capability in a 1.14×1.44 mm Flip-Chip - making it the only fit for space-constrained, multi-voltage, battery-depletion-aware wearable designs.

Availability

ST1PS01BJR is available at Aetrix Electronics and suitable for wearable applications, Bluetooth® low energy nodes, and energy-harvesting sensor tags requiring stable component supply across long-lifecycle consumer and industrial programs.

Supply support for ST1PS01BJR 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 industrial, automotive, and consumer markets.

The ST1PS01 series belongs to ST's nano-power DC-DC converter product line, engineered specifically for ultra-thin, battery-operated wearables and IoT edge sensors where PCB area, thickness, and multi-year runtime are non-negotiable design constraints.

FAQ

What is the minimum input voltage required for ST1PS01BJR to start switching?

The device begins regulation when input voltage rises above the UVLO threshold of 1.63 V (typical). Below this, internal circuitry remains disabled. Once enabled, it sustains operation down to 1.57 V (falling threshold) before shutting off - ensuring clean start-up and graceful brown-out behavior in fading battery conditions.

Can ST1PS01BJR dynamically change output voltage during operation?

Yes - D0 and D1 pins support real-time VOUT reconfiguration (1.1 V ↔ 1.2 V ↔ 1.5 V ↔ 1.7 V) as long as VIN ≥ selected VOUT + 300 mV. This enables adaptive power scaling for different MCU operating modes without external components or firmware overhead.

Does ST1PS01BJR require an external resistor divider for feedback?

No - ST1PS01BJR uses internal precision voltage references and digital selection logic. All four output voltages are factory-trimmed and accessed solely via D0/D1 logic states; no external resistors, trimming, or calibration are needed.

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

In 100% mode, the high-side MOSFET conducts continuously, connecting VIN directly to VOUT through the inductor. Output voltage equals VIN minus IR drop across the MOSFET (R_DS(on) ≈ 0.4 Ω) and inductor DCR - providing unregulated but functional power extension below normal regulation range.