一文详解ADI LTC6813－1多颗电池监测解决方案

ADI公司的LTC6813-1是可测量到多达18颗串接电池连接的监视器，总测量误差小于2.2mV，电池测量范围0-5V，所有18颗电池测量时间在290μs，内置isoSPI™接口，主要用在电动和混合动力汽车以及备份电池系统。本文介绍了LTC6813-1主要特性，框图和多种应用电路，以及演示板DC2350A主要性能和电路图。

The LTCR6813-1 is a multicell battery stack monitor thatmeasures up to 18 series connected battery cells witha total measurement error of less than 2.2mV. The cell measurement range of 0V to 5V makes the LTC6813-1suitable for most battery chemistries. All 18 cells can bemeasured in 290μs， and lower data acquisition rates canbe selected for high noise reduction.

Multiple LTC6813-1 devices can be connected in series，permitting simultaneous cell monitoring of long， highvoltage battery strings. Each LTC6813-1 has an isoSPIinterface for high speed， RF immune， long distance communications.Multiple devices are connected in a daisychain with one host processor connection for all devices.

This daisy chain can be operated bidirectionally， ensuringcommunication integrity， even in the event of a fault alongthe communication path.

The LTC6813-1 can be powered directly from the batterystack or from an isolated supply. The LTC6813-1 includespassive balancing for each cell， with individual PWM dutycycle control for each cell. Other features include an onboard5V regulator， nine general purpose I/O lines and asleep mode， where current consumption is reduced to 6μA.

LTC6813-1主要特性：

nnMeasures Up to 18 Battery Cells in Series

nn2.2mV Maximum Total Measurement Error

nnStackable Architecture Supports 100s of Cells

nnBuilt-In isoSPI™ Interface

nn1Mb Isolated Serial Communications

nnUses a Single Twisted Pair， Up to 100 Meters

nnLow EMI Susceptibility and Emissions

nnBidirectional for Broken Wire Protection

nn290μs to Measure All Cells in a System

nnSynchronized Voltage and Current Measurement

nn16-Bit Delta-Sigma ADC with Programmable3rd Order Noise Filter

nnEngineered for ISO 26262-Compliant Systems

nnPassive Cell Balancing Up to 200mA （Max） withProgrammable Pulse‑Width Modulation

nn9 General Purpose Digital I/O or Analog Inputs

nnTemperature or Other Sensor Inputs

nnConfigurable as an I2C or SPI Master

nn6μA Sleep Mode Supply Current

nn64-Lead eLQFP Package

LTC6813-1应用：

nnElectric and Hybrid Electric Vehicles

nnBackup Battery Systems

nnGrid Energy Storage

nnHigh Power Portable Equipment

图1.LTC6813-1框图

图2.LTC6813-1变压器隔离菊花链配置图

图3.LTC6813-1采用2线端口A的连接图

图4.LTC6813-1可逆isoSPI菊花链接图

图5.LTC6813-1单板菊花链接口元件图

图6.LTC6813-1同一PCB的电容隔离耦合图

图7.LTC6813-1 16颗和14颗电池连接图

演示板DC2350A

Demonstration circuit 2350A is a multicell battery stackmonitor featuring the LTC®6812-1， a 15-cell monitor onthe DC2350A-A， or the LTC6813-1， an 18-cell monitor onthe DC2350A-B. Multiple boards can be linked through a2-wire isolated serial interface （isoSPI） to monitor anynumber of cells in a stack. The demo circuit also featuresreversible isoSPI enabling a fully redundant communicationpath.

The DC2350 can communicate to a PC by connectingdirectly to a DC2026 Linduino® One. The DC2026 must beloaded with the appropriate program （called a “sketch”）to control the battery stack monitor IC and receive datathrough a USB serial port. The DC2792/DC1941 can beconnected to the DC2026 to provide a fully isolated isoSPI interface to the DC2350.

演示板DC2350A主要性能：

图8.演示板DC2350A电路图（1）

图9.演示板DC2350A电路图（2）