STMicroelectronics STBC03JR

Overview

STBC03JR from STMicroelectronics is a highly integrated Li-Ion linear battery charger IC with embedded 150 mA LDO regulator, two 3 Ω SPDT load switches, and protection circuit module (PCM). It delivers CC/CV charging up to 650 mA, programmable floating voltage up to 4.45 V, and <10 nA battery leakage in shipping mode - optimized for space-constrained wearable devices requiring ultra-low quiescent power and autonomous fault management.

For engineers reviewing the STBC03JR datasheet, STBC03JR pinout, STBC03JR application, or STBC03JR equivalent, this device supports precise battery gauging via BATMS/BATSNS pins, thermal monitoring via NTC interface, automatic power path selection between IN and BAT, and dual-load-switch control for system-level power sequencing in compact Li-Poly powered systems.

Technical Context

The STBC03JR implements a dual-stage CC/CV charge algorithm with independently programmable fast-charge (via ISET) and pre-charge (via IPRE) currents, end-of-charge termination at 5% of IFAST, and floating voltage adjustment through BATSNSFV resistor network. Its PCM monitors overcharge (VOCHG = 4.275 V), over-discharge (VODC = 2.8 V), and discharge overcurrent (IBATOCP = 900 mA) with deglitch timers (tOCD = 1.2 s, tODD = 60 ms).

Power routing is managed dynamically: SYS draws from VIN when valid (4.55–5.4 V), otherwise from BAT; LDO delivers regulated 3.0 V ±0.1 V at up to 150 mA; and two SPDT switches (RON ≈ 2.0–3.8 Ω) support bidirectional 1.8–5 V signal/power routing with independent enable inputs (SW_SEL1/SW_SEL2) referenced to LDO level.

Key Specifications

Pinout & Package

STBC03JR is housed in a Flip Chip 30 package (2.25 × 2.59 mm, 400 µm pitch) with 30 bumps arranged in a 6×5 grid. The package supports high-density PCB layout and provides robust thermal performance (R_THJB = 50 °C/W on FR4).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Li-Ion linear charger with integrated LDO and protection applications.

Compared with BQ24075RGTR and MAX1555, STBC03JR provides higher integration (LDO + dual SPDT switches + PCM), wider VFLOAT range (4.179–4.45 V), and hardware-enforced thermal derating - reducing BOM count by ≥4 components and enabling safer, longer-life wearable deployments.

Availability

STBC03JR is available at Aetrix Electronics and suitable for smart wearables, fitness trackers, medical sensors, and portable diagnostic devices requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for STBC03JR 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 solutions for industrial, automotive, and consumer markets.

The STBC03JR belongs to ST's STBC family of highly integrated battery chargers targeting ultra-low-power portable electronics - engineered specifically to reduce system-level complexity in space-constrained, battery-operated devices with stringent safety and shelf-life requirements.

FAQ

What is the minimum input voltage required to initiate charging on STBC03JR?

The STBC03JR requires VIN ≥ 4.55 V (typical) to enter charging mode, with undervoltage lockout releasing at 3.9 V and hysteresis of 300 mV. Below 4.55 V, the device remains in standby or battery-powered mode. Input overvoltage protection activates at 5.6–6.4 V, ensuring safe operation across USB-compliant sources.

How does the STBC03JR handle battery temperature monitoring?

The STBC03JR uses the NTC pin to interface with an external thermistor (typically 10 kΩ, β = 3370), detecting hot (>45 °C) and cold (<0 °C) conditions via VHOT (0.246 V typ) and VCOLD (1.355 V typ) thresholds. Charging halts immediately upon violation, and the CHG pin signals NTC fault with 16.2 Hz toggling until temperature returns to safe range.

Can the STBC03JR operate without an NTC thermistor?

Yes - the NTC thermistor is optional. If omitted, a 10 kΩ pull-up resistor must be connected from NTC to LDO (3.0 V) to ensure proper biasing and avoid undefined behavior. Without NTC, thermal protection is disabled, but all other functions - charging, LDO, load switches, and PCM - remain fully operational.

What happens to the SYS rail when the input supply (IN) is disconnected?

When IN falls below VUVLO (3.9 V), the STBC03JR automatically switches SYS sourcing from IN to BAT, maintaining uninterrupted system power. This power-path transition occurs seamlessly with no voltage glitch, provided BAT voltage exceeds VODCR (3.0 V); if BAT drops below VODC (2.8 V), SYS shuts down to protect the cell.