This reference design provides a comprehensive solution for advanced battery management, emphasizing efficiency, safety, and reliability across various high-cell-count and high-voltage applications.
N-channel MOSFET control battery pack lies in its superior efficiency, reliability, and versatility in managing high-cell-count, high-voltage applications. Utilizing N-channel MOSFETs allows for better thermal performance and lower resistance, resulting in enhanced energy efficiency and longer battery life. This type of control architecture is crucial for applications requiring precise monitoring and protection of battery cells, such as in electric vehicles, portable power stations, and industrial energy storage systems. The ability to seamlessly manage cell voltage, pack current, and temperature ensures safe and optimal performance, making N-channel MOSFET control battery packs an essential component in modern, high-demand battery management systems.
This reference design TIDA-010247 by Texas Instruments outlines a high-side, N-channel MOSFET control battery pack capable of managing up to 32 series cells using the BQ769x2 battery monitor family. The design meticulously monitors each cell’s voltage, pack current, and the temperature of both cells and MOSFETs, ensuring secure and safe battery pack operation. Its high-side N-channel MOSFET architecture, coupled with optimized driving circuits, facilitates effortless switch control. This reference design boasts low stand-by and ship-mode consumption and fine-tunes the current gaps between two groups, making it ideal for high-cell-count, high-voltage battery-pack applications.
Efficiency, Accuracy, and Robust Protection
The design include a 300-μA consumption in standby mode, ensuring minimal power draw and contributing to overall energy efficiency. In ship mode, the design achieves an ultra-low consumption of 10 µA, preserving battery life during long-term storage. The voltage accuracy is maintained at ±5-mV at 25°C without calibration, enhancing the reliability of battery management. Robust and programmable protection provides comprehensive safety for both battery cells and the system, customizable to specific needs. The high-side N-channel MOSFETs with strong driving capability facilitate efficient and reliable control over the switching elements.
For power source and efficiency, the design integrates a 120-V input, 0.3-A, ultra-low IQ synchronous buck DC/DC converter (LM5168P) and a low IQ 0.3-A LDO (TPS7A25) as the main power sources. When operating in normal mode, which requires significant current along with CAN or RS-485 communications, this setup offers better efficiency and thermal performance compared to LDO-only configurations. The high-side N-channel MOSFET architecture and the BQ76942 charge pump support driving and voltage management. The top BQ76942 references the top of the bottom stack for cell voltage measurement. When the DSG MOSFET turns off, discrete components ensure the DSG MOSFET turns off completely and swiftly, even with high voltage on the DSG pin.
The design incorporates several integrated components: the BQ76942, a highly-integrated, high-accuracy battery monitor and protector for 3-series to 10-series Li-ion, Li-polymer, and LiFePO4 battery packs; the LM5169 and LM5168 synchronous buck converters, designed to regulate a wide input voltage range, minimizing the need for external surge suppression components; ISO164x devices, which are hot-swappable, low-power, bidirectional isolators compatible with I2C interfaces, enhancing communication reliability; and a CAN transceiver family that meets ISO11898-2 (2016) High-Speed CAN physical layer standard, suitable for CAN FD networks up to 2Mbps. The THVD2410 and THVD2450 devices are ±70-V fault-protected, half-duplex RS-422, RS-485 transceivers, ensuring robust communication in industrial environments. Applications for this reference design include battery packs for e-bikes, e-scooters, and light electric vehicles (LEVs); industrial battery packs for configurations with 10 or more series cells; portable power stations; and battery energy storage systems.
TI have tested this reference design. It comes with a bill of materials (BOM), schematics, an assembly drawing, a gerber file, etc. You can find additional data about the reference design on the company’s website. To read more about this reference design, click here.
