STMicroelectronics STEVAL-ISB002V1

Overview

STEVAL-ISB002V1 from STMicroelectronics is a universal battery charger (UBC) demonstration board based on the ST72F324LK2T6 8-bit microcontroller, implementing a modified non-inverting buck-boost topology for single-cell Li-ion and 2-cell NiMH charging from a 5 V supply, featuring 1 % measurement accuracy, embedded 3.3 V KF33 LDO regulator, and TL1431-based precision voltage reference.

For engineers reviewing the STEVAL-ISB002V1 datasheet, STEVAL-ISB002V1 pinout, STEVAL-ISB002V1 application, or STEVAL-ISB002V1 equivalent, key selection considerations include its firmware-upgradeable ST7 platform, NTC-integrated thermal monitoring, ±1 % charge voltage regulation, dual-battery support (Li-ion/NiMH), and integrated status LED feedback for real-time charging state indication.

Technical Context

The board implements a microcontroller-driven constant-current/constant-voltage (CC/CV) charging algorithm using the ST72F324LK2T6's ADC (AIN0, AIN1, AIN8, AIN14), PWM outputs (PWM-1, PWM-2), and ICC interface for firmware updates. Charging control relies on analog sensing via precision resistors (R17/R16: 0.1 % tolerance) and TL1431 reference (±0.5 % initial accuracy).

Power architecture includes a 75 µH/1 A inductor (L1), dual Schottky diodes (D1/D2: 1N5821), and discrete MOSFETs (Q1/Q2/Q6: 2STR1215) for synchronous switching. The KF33BDTR provides regulated 3.3 V for MCU and analog circuitry, while the LM258AD op-amp (U3) conditions battery voltage and current sense signals.

Key Specifications

Availability

STEVAL-ISB002V1 is available at Aetrix Electronics and suitable for battery management system prototyping, portable medical device charger validation, and consumer electronics power subsystem development requiring stable component supply and legacy ST7 platform support.

Supply support for STEVAL-ISB002V1 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, designing and manufacturing microcontrollers, power ICs, sensors, and analog/mixed-signal devices for industrial, automotive, and consumer applications.

The STEVAL evaluation board series targets rapid prototyping of ST's proprietary power management and microcontroller solutions, emphasizing reference design fidelity, firmware flexibility, and application-specific signal conditioning.

FAQ

What battery chemistries does STEVAL-ISB002V1 support?

STEVAL-ISB002V1 supports single-cell Li-ion batteries (charged to 4.2 V) and 2-cell NiMH batteries (charged to 2.8–3.0 V per cell). It uses NTC thermistor input (RT1) for temperature-aware charging and includes dedicated LED indicators for each chemistry's charging state.

Can the firmware be updated or customized?

Yes - the board features an ICC (In-Circuit Communication) interface (ICCSEL, ICCDATA, ICCCLK pins) compatible with ST's STVP programming tool. Firmware is written in C for the ST72F324LK2T6 and can be modified to adapt charge profiles, add communication protocols, or port to other ST7 derivatives.

What is the role of the TL1431 and KF33 regulators on this board?

The TL1431AIZ provides a precision 2.5 V reference (±0.5 %) for ADC-based battery voltage measurement and CV loop stability. The KF33BDTR delivers a regulated 3.3 V / 2 A supply for the ST72F324LK2T6 MCU, LM258AD op-amps, and digital logic, ensuring noise-immune analog performance.

Is STEVAL-ISB002V1 still in active production?

No - STEVAL-ISB002V1 is marked "Obsolete Product(s)" in the official ST document (Doc ID 18257 Rev 1, Nov 2010). It remains available through authorized distributors for legacy design support, but no new silicon revisions or firmware updates are planned by STMicroelectronics.