High Voltage, Precision, Battery Stack Monitor

Linear Technology announces the LTC6802®, a highly integrated multicell battery monitoring IC capable of measuring up to 12 individual battery cells. Using a novel stacking technique, multiple LTC6802s can be stacked in series without opto-couplers or isolators, allowing precision voltage monitoring of every cell in long strings of series connected batteries. Long battery strings enable high power, rechargeable battery applications, such as electric & hybrid electric vehicles, scooters, motorcycles, golf carts, wheelchairs, boats, submarines, forklifts, robotics and portable medical equipment. 

The LTC6802-1 is a complete battery monitoring IC that includes a 12-bit ADC, a precision voltage reference, a high voltage input multiplexer and a serial interface. Each LTC6802-1 can measure up to 12 series connected battery cells with an input common mode voltage up to 60V. In addition, multiple LTC6802-1 devices can be placed in series to monitor the voltage of each cell in a long battery string. The unique level-shifting serial interface allows the serial ports of these devices to be daisy-chained without optocouplers or isolators. 

When multiple LTC6802-1 devices are connected in series they can operate simultaneously, permitting all cell voltages in the stack to be measured within 13ms. To minimize power, the LTC6802-1 offers a measure mode, which simply monitors each cell for overvoltage and undervoltage conditions. A standby mode is also provided. Each cell input has an associated MOSFET switch for discharging overcharged cells. For large battery stack applications requiring individually addressable serial communications, see the LTC6802-2. 

The maximum total measurement error is guaranteed to be less than 0.25% from -40°C to 85°C and every cell voltage in a battery stack can be measured within 13ms. Each cell is monitored for under voltage and over voltage conditions and an associated MOSFET switch is available to discharge over-charged cells. Each LTC6802 communicates via a 1MHz serial interface. Also included are temperature sensor inputs, GPIO lines and a precision voltage reference. The LTC6802 is a small 8mm x 12mm surface mount device. The combined robustness, exceptional precision and tiny package directly addresses the critical requirements of emerging and advanced battery technologies. 

Features

  • Measures up to 12 Li-Ion Cells in Series (60V Max)
  • Stackable Architecture Enables >1000V Systems
  • 0.25% Maximum Total Measurement Error
  • 13ms to Measure All Cells in a System
  • Cell Balancing:
    • On-Chip Passive Cell Balancing Switches
    • Provision for Off-Chip Passive Balancing
  • Two Thermistor Inputs Plus On-Board
  • Temperature Sensor
  • 1MHz Daisy-Chainable Serial Interface
  • High EMI Immunity
  • Delta Sigma Converter with Built-In Noise Filter
  • Open Wire Connection Fault Detection
  • Low Power Modes
  • 44-Lead SSOP Package 

Applications

  • Electric and Hybrid Electric Vehicles
  • High Power Portable Equipment
  • Backup Battery Systems
  • High Voltage Data Acquisition Systems 

Want to Read More? Please Sign In

If you have already registered with us, you can sign in here to access this content. If not, register now and get full access to our entire On Demand library of webcasts, white papers and more. Registration is free. Click Here to Register


 
    submit to reddit  

Comments:

You must be logged in to leave a reply. Login »

Full Whitepaper Available for Download

If you already have registered with us, Sign In Here

Not a member yet? Register now!

It's free and will give you access to this and our entire collection of webcasts, videos, whitepapers and more. Register Now

Sign In  Register

Recent Article Mentions

The Year in EDA

Did Anything Happen?

Learning The Language of Analog Design

What Mistakes to Make and What Mistakes Not to Make

A Little Extra Power on the Side

With a Little Guy Trying to Exert Some Power of His Own

Making Analog Fun

The Life and Times of Jim Williams

Riding the Rails

Linear Technology Makes Power Fun?


Login Required

In order to view this resource, you must log in to our site. Please sign in now.

If you don't already have an acount with us, registering is free and quick. Register now.

Sign In    Register