Maxim公司的MAX17320是38μA IQ单独可用的电池侧电量计量集成电路,具有保护器,电池内部自放电检测和选择SHA-256认证,用于2到4串接锂电池/聚合物电池.器件检测电压,电流,温度和电池状态, 采用外接高边N-FET以提供对过压/欠压,过流,短路,超温/低温,过充和内部自放电条件的保护,并提供充电预描述以保证电池工作在安全条件,从而延长了电池寿命. MAX17320采用内部的FET来平衡电池.在预先通过鉴定的充电,器件采用CHGFET进行线性控制充电.电量计量采用该公司的ModelGaugeTM m5算法,组合了短期精度和库仑计线性度,以及基于电压的电量计量长期稳定性,从而提供业界一流的电量计量精度. MAX17320能自动补偿电池老化,温度,放电速率,在各种工作状态下能以毫安时(mAh)或百分比(%)提供精确的电荷状态(SOC).器件提供可配置的常开的LDO,能给系统侧的小型临界负载供电,即使在故障情况下也不会对电池造成过载.动态功率功能提供瞬态最大电池输出功率. MAX17320提供1-Wire®或2-wire I2C/SMBus接口,对数据和控制寄存器进行存取.器件采用无铅2.4mm x 2.6mm 30凸0.4mm 间隔WLP封装和4mm x 4mm 24引脚TQFN封装.主要用在智能手机,平板电脑和2合1膝上型计算机,医疗设备,健康和健美监视器,数码相机,录相机和动作摄像机,手持计算机,无线电和终端,电动工具,无线扬声器和无人机,智能电池和备份电池.本文介绍了MAX17320主要优势和特性,框图和典型应用电路图,评估板MAX17320X/MAX17320G EVK主要特性,电路图,材料清单和PCB设计图.

 The MAX17320 is a 38μA IQ stand-alone pack-side fuel gauge IC with protector, battery internal self-discharge de­tection, and optional SHA-256 authentication for 2 to 4 se­ries lithium-ion/polymer batteries.

The IC monitors the voltage, current, temperature and state of the battery to provide protection against over/un­dervoltage, overcurrent, short-circuit, over/undertempera­ture, overcharge, and internal self-discharge conditions using external high-side N-FETs, and provides charging prescription to ensure that the battery operates under safe conditions, thereby prolonging the life of the battery. The IC balances the cells using internal FETs. During prequal charging, the IC uses the CHGFET to linearly control charging.

To prevent battery pack cloning, the IC integrates SHA-256 authentication with a 160-bit secret key. Each IC incorporates a unique 64-bit ID.

The fuel gauge uses Maxim ModelGaugeTM m5 algorithm that combines the short-term accuracy and linearity of a coulomb counter with the long-term stability of a voltage-based fuel gauge to provide industry-leading fuel gauge accuracy. The IC automatically compensates for cell ag­ing, temperature, and discharge rate, and provides accu­rate state-of-charge (SOC) in milliampere-hours (mAh) or percentage (%) over a wide range of operating conditions.

The IC provides a configurable always-on LDO that can power small critical loads on the system side without over­loading the cells even under fault conditions. Dynamic power functionality provides the instantaneous maximum battery output power which can be delivered to the system without violating the minimum system input voltage.

A Maxim 1-Wire® or 2-wire I2C/SMBus interface provides access to data and control registers. The IC is available in a lead-free, 2.4mm x 2.6mm 30-bump 0.4mm pitch WLP and 4mm x 4mm 24-pin TQFN packages.

MAX17320主要优势和特性:

● Battery Health + Programmable Safety/Protection

• Overvoltage (Temperature Dependent)

• Overcharge/Overdischarge/Short-Circuit Current

• Over/Undertemperature

• Undervoltage + SmartEmpty

• Battery Internal Self-Discharge Detection

• Ideal Diode Discharge During Charge Fault

• Charging Prescriptions (JEITA)

• Prequal Charge Control with CHG FET

● ModelGauge m5 EZ Algorithm

• Percent, Capacity, Time-to-Empty/Full, Age

• Cycle+™ Age Forecast

● Precision Measurement Without Calibration

• Current, Voltage, Power, Time, Cycles

• Die Temperature, 4 Thermistors ±1˚C

● Cell Balancing with Internal FETs

● SHA-256 Authentication

● Nonvolatile Memory for Stand-Alone Operation

• History Logging, User Data (84 Bytes)

● Low Quiescent Current

• FETs Enabled: 38μA Active

● Pushbutton Wakeup—Eliminates System Consumption Until Button Press

● Always-On LDO

● Dynamic Power—Estimates Power Capability

● SBS 1.1 Compatible Register Set

MAX17320应用:

● Smartphones, Tablets, and 2-in-1 Laptops

● Medical Devices, Health and Fitness Monitors

● Digital Still, Video, and Action Cameras

● Handheld Computers, Radios, and Terminals

● Power Tools, Wireless Speakers, and Drones

● Smart Batteries and Battery Backup

图1.MAX17320框图

图2.MAX17320典型应用电路图

图3.MAX17320 2S-4S电池组和系统实现图

图4.MAX17320带保险丝的应用电路图

评估板MAX17320X/MAX17320G EVK

The MAX17320X/MAX17320G evaluation kits (EV kits) are fully assembled and tested surface-mount PCBs that evaluate the stand-alone pack-side fuel gauge IC with protector and optional SHA-256 authentication for 2-4 cell lithium-ion/polymer batteries.

The MAX17320 EV kits include the IC evaluation board with integrated I2C/1-Wire® interface and USB micro-B cable. Windows® based graphical user interface (GUI) software is available for use with the EV kit and can be downloaded from https://www.maximintegrated.com/ products/MAX17320.html/ product page under “Design Resources” tab. Windows 7 or newer Windows operating system is required to use with the EV kit GUI software.

评估板MAX17320X/MAX17320G EVK主要特性:

ModelGauge m5 Algorithm

Monitors Multicell Packs

Full Protection Solution On-Board for Evaluation

Battery Pack Input Voltage Range of +2.3V to +4.9V/ Cell with Default Hardware

Default Current Range -10A to +10A with 5mΩ Sense Resistor, Higher Currents Can Be Supported by Changing to a Smaller Sense Resistor

Thermistor Measurement

On-Board I2C/1-Wire Communication Interface with Built-In MAXUSB Interface

Windows 7 or Newer Compatible Software

Proven PCB Layout

Fully Assembled and Tested

图5.评估板MAX17320 EVK连接图

图6.评估板MAX17320X EVK外形图

图7.评估板MAX17320X EVK电路图(1)

图8.评估板MAX17320X EVK电路图(2)

评估板MAX17320X EVK材料清单:

图9.评估板MAX17320X EVK PCB设计图:左:顶层丝印;右:顶层

图10.评估板MAX17320X EVK PCB设计图:左:层2;右:层3

图11.评估板MAX17320X EVK PCB设计图:左:底层;右:底层丝印

评估板MAX17320G EVK材料清单:

图12.评估板MAX17320G EVK电路图(1)

图13.评估板MAX17320G EVK电路图(2)

图14.评估板MAX17320G EVK PCB设计图(1):左:顶层丝印;右:顶层

图15.评估板MAX17320G EVK PCB设计图(2):左:层2;右:层3

图16.评估板MAX17320G EVK PCB设计图(3):左:底层;右:底层丝印