STMicroelectronics ST1PS01CJR

Overview

ST1PS01CJR 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 (1.0 V, 1.2 V, 1.3 V, or 1.5 V) via D0/D1 pins. It integrates Power Good flag, 100% duty cycle operation, and soft-start for ultra-low-power wearable and energy-harvesting systems.

For engineers reviewing the ST1PS01CJR datasheet, ST1PS01CJR pinout, ST1PS01CJR application, or ST1PS01CJR equivalent, this page delivers verified technical context, exact pin functions, real-world efficiency data at microamp loads, dynamic voltage scaling behavior, and validated alternatives for battery-constrained designs.

Technical Context

The ST1PS01CJR employs peak current control (PCC) with hysteretic mode transition between PFM and PWM to maintain constant inductor ripple current across load ranges from 1 µA to 400 mA. Its 100% duty cycle mode directly connects VIN to VOUT when input approaches selected output voltage, minimizing dropout loss.

It features integrated output discharge (30 Ω on-resistance), undervoltage lockout (1.57 V falling threshold), and dynamic VOUT selection with ±1.5% accuracy at 25 °C - all enabled by digital inputs referenced to VIN, not ground, supporting true rail-to-rail voltage scaling during operation.

Key Specifications

Pinout & Package

ST1PS01CJR uses the Flip-Chip8 package (1.14 mm × 1.44 mm, 0.55 mm max height), optimized for minimal PCB area and thickness in space-constrained applications like smart bands and medical patches.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS62840 and ADP5302, ST1PS01CJR uniquely combines nano-IQ, digital VOUT selection, PGOOD, and 100% duty cycle in one Flip-Chip8 package - enabling smaller, simpler, and more adaptive power architectures for next-gen wearables.

Availability

ST1PS01CJR is available at Aetrix Electronics and suitable for wearable fitness monitors, Bluetooth® low energy sensor nodes, and energy-harvesting wireless transmitters requiring stable component supply with guaranteed long-term lifecycle support.

Supply support for ST1PS01CJR 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 silicon solutions for automotive, industrial, and consumer markets since 1987.

The ST1PS01 series targets ultra-low-power portable electronics - specifically engineered to replace linear regulators and legacy buck converters in space- and energy-constrained applications where PCB area, thickness, and multi-year battery life are critical.

FAQ

What is the minimum input voltage required for ST1PS01CJR to start switching?

The ST1PS01CJR enters regulation when VIN rises above 1.63 V (typical UVLO threshold). Below this, the device remains disabled with 10 nA shutdown current. Once enabled, it sustains operation down to 1.57 V (falling threshold) before latching off - ensuring stable startup from weak or decaying sources like partially discharged batteries.

Can D0 and D1 pins be left unconnected or tied to GND/VIN directly?

No - D0 and D1 must be actively driven to defined logic levels (GND or VIN) using low-impedance connections. Floating or high-impedance ties cause undefined output voltage and potential regulation failure. The datasheet specifies these pins are VIN-referenced, so pull-up/pull-down resistors must connect to VIN, not system ground.

How does the 100% duty cycle mode affect output voltage accuracy and dropout?

In 100% mode, the high-side MOSFET conducts continuously, so VOUT = VIN − I_OUT × (R_DS(on) + R_INDUCTOR). With R_DS(on) = 0.38 Ω and typical 2.2 µH inductor DCR < 100 mΩ, dropout remains under 150 mV at 400 mA - preserving tight regulation near battery end-of-life without external components.

Is the PGOOD signal internally pulled up, or does it require an external resistor?

PGOOD is an open-drain output and requires an external pull-up resistor (typically 1 MΩ to VIN) to generate a valid logic-high signal. Without it, PGOOD remains floating when active - causing unreliable reset assertion or sequencing errors. The datasheet confirms this in Table 2 and Section 7.6.