TI公司的bq77910是4-10個(gè)鋰電池組的精密保護和平衡解決方案,采用內部的FET可對單個(gè)電池進(jìn)行監視和平衡,直接驅動(dòng)NMOS功率FET,和1毫歐姆或5歐姆檢測電阻兼容,低靜態(tài)電流,主要應用在無(wú)繩電動(dòng)工具,無(wú)繩割草機,電動(dòng)自行車(chē),UPS,醫療設備和小型電動(dòng)汽車(chē)(LEV).本文介紹了bq77910主要特性和優(yōu)勢,方框圖,多種應用配置圖以及bq77910EVM-001評估模塊主要特性,電路圖和材料清單.
The bq77910 precision protector is an integrated battery-protection and cell-balancing solution for Li-Ion battery packs. A single device can be configured to manage 4 to 10 cell battery packs. Two devices can be stacked to provide a solution for packs up to 20 cells in series.
This protection IC monitors individual cell voltages and can directly drive N-channel power MOSFETs to interrupt current flow during fault conditions. Fault detection and recovery criteria are fully programmable in non-volatile memory to suit all types of Li-Ion systems.Automatic cell balancing is provided using internal FETs. A robust balancing algorithm ensures optimum performance over the entire operating life of the pack.

bq77910主要特性:
4 ~ 10 series cell protection capability
Individual cell monitoring and balancing with internal FETs
NMOS power FET direct drive capability with flexible FET configuration
Compatible with 1 or 5 milliohm sense resistor
Low Quiescent Current (50 µA ON, 2.5 µA shutdown mode)
Programmable fault detection thresholds and time delays

bq77910優(yōu)勢:
Adaptable to a wide range of applications including power tools, E-Bikes, and UPS equipment
Maximizes battery pack service life and performance; minimizes external components required
Reduces total system cost and allows scaling of FETs as required for variable charging and discharge rates (application-specific)
Allows system designer to optimize for minimal loss or maximum sense accuracy as required by each application
Minimizes battery discharge during storage or idle periods
Adaptable to all variations of Li-Ion systems (LiCoO2, LiFePO4, and others)

bq77910應用:
• Cordless Power Tools
• Cordless Lawn Equipment
• Electric Bikes
• UPS
• Medical Equipment
• Light Electric Vehicles (LEV)

圖1.bq77910功能方框圖

圖2.bq77910 5個(gè)電池串聯(lián)FET配置圖

圖3.bq77910 采用CHGST引腳的串聯(lián)FET配置圖

圖4.bq77910采用CHGST引腳并聯(lián)(分離)電源通路FET配置圖

圖5.bq77910采用CHGST引腳不帶充電FET的分離電源通路配置圖

圖6.bq77910單電源通路無(wú)FET配置圖

圖7.bq77910 VCELLx引腳不用時(shí)的配置圖

bq77910EVM-001評估模塊
The bq77910EVM-001 evaluation module (EVM) is a complete evaluation system for the bq77910, a four=to ten-cell Li-ion battery protection integrated circuit. The EVM consists of a bq77910 circuit module and a resistor cell simulator module which can be used for simple evaluation of the bq77910 functions. The circuit module includes one bq77910 integrated circuit (IC), sense resistor, power FETs and all other onboard components necessary to protect the cells from overcharge, over discharge, short circuit, and over current discharge in a 10 series cell Li-ion or Li-polymer battery pack. The circuit module connects directly across the cells in a battery. With a compatible interface board and Windows™-based PC software, the user can view the bq77910 registers and program the IC configuration and protection limits
If a designer wants to communicate with this EVM from a Windows-based PC, a separate USB Interface Adapter EVM is recommended. The USB-TO-GPIO Adapter serves as an interface adapter or a bridge between a host PC (IBM compatible) and one or multiple slave devices via a standard type-A to mini-B USB cable. The USB-TO-GPIO Adapter is listed below in the related tools section

bq77910EVM-001評估模塊主要特性:
Complete evaluation system for the bq77910 four to ten series cell lithium-ion or lithium-polymer battery protector
Populated circuit module for 10 cell parallel FET configuration for quick setup - Pads for components for configuration of additional cell counts and series FETs
Power connections available on terminal blocks or banana jacks
Control and status signals available on terminal blocks
Resistor cell simulator for quick setup with only a power supply
PC software available for configuration

圖8.bq77910EVM-001評估模塊外形圖

圖9.bq77910EVM-001評估模塊基本連接圖

圖10.bq77910EVM-001評估模塊電路圖(1)

圖11.bq77910EVM-001評估模塊電路圖(2)

圖12.電阻模擬器電路圖

圖13.bq77910EVM-001評估模塊元件布局圖
電阻模擬器材料清單:

bq77910EVM-001評估模塊材料清單(BOM):