CN0235 is a Fully Isolated Lithium Ion Battery Monitoring System. Lithium ion (Li-Ion) battery stacks contain a large number of individual cells that must be monitored correctly in order to enhance the battery efficiency, prolong the battery life, and ensure safety.

The 6-channel AD7280A devices act as the primary monitor providing accurate voltage measurement data to the System Demonstration Platform (SDP-B) evaluation board, and the 6-channel AD8280 devices act as the secondary monitor and protection system. Both devices can operate from a single wide supply range of 8V to 30 V and operate over the industrial temperature range of ?40°C to +105°C

The AD7280Acontains an internal ±3 ppm reference that allows a cell voltage measurement accuracy of ±1.6 mV. The ADC resolution is 12 bits and allows conversion of up to 48 cells within 7 μs. It also has cell balancing interface outputs designed to control external FET transistors to allow discharging of individual cells and forcing all the cells in the stack to have identical voltages.

The AD8280 functions independently of the primary monitor and provides alarm functions indicating out of tolerance conditions. It contains its own reference and LDO, both of which are powered completely from the battery cell stack. The reference, in conjunction with external resistor dividers, is used to establish trip points for the over/undervoltages. Each cell channel contains programmable deglitching (D/G) circuitry to avoid alarming from transient input levels.

• EVAL-CN0235-SDPZ Evaluation Board
• EVAL-SDP-CB1Z Evaluation Board
• CN0235 Evaluation Software
  • (supplied with provided CD in kit)
• USB Type-A plug to USB Mini-B plug cable
• +6V “Wall Wart”
• PC with minimum requirement:
  • Windows XP SP2, Windows Vista or Windows 7 Business/Enterprise/Ultimate editions
  • Intel Pentium processor (x86 compatible), 1GHz or faster
  • 512 MB RAM and 2 GB available hard disk space
  • .NET 3.5 Framework

• The EVAL-CN0235-SDPZ (CN0235 Board) connects to the EVAL-SDP-CB1Z (SDP-B board)
• The EVAL-CN0235-SDPZ (CN0235 Board) is powered by a +6V Wall wart via the DC barrel jack.
• The EVAL-SDP-CB1Z (SDP-B board) connects to the PC via the USB-cable.

1. SDP USB connection – Connect to PC through USB Type A to mini-USB.
2. Jumper Configuration – Sets AD8280 and AD7280A configuration. Jumper configuration setting is explained further on the next section.
3. VIN0 to VIN6 – Lithium Ion battery stacks input. This connector is used when only one device is required.
   

   NOTE: Please see AD7280A Datasheet page 17 and page 22 for proper battery connection for different number of cells.

4. VIN7 to VIN12 – Lithium Ion battery stacks input. This connector is used when two devices are required for the application.
   

   NOTE: Please see AD7280A Datasheet page 18 for proper battery cell connection using two devices.

5. Power Supply – The board may be powered up using a +6V wall-wart connected to the barrel jack or using an external power supply configured to +6V.
6. SPI breakout pins – These are the breakout pins of the digital lines coming from the SDP board to AD7280A devices.

1. Extract the file CN0235 Eval Software.zip and open the file setup.exe.
   
   

   NOTE: It is recommended that you install the CN0235 Evaluation Software to the default directory path C:/Program Files/Analog Devices/CN0235/ and all National Instruments products to C:/Program Files/National Instruments/

   

2. Click Next to view the installation review page
   
   
   
   
3. Click Next to start the installation
   
   
   
   
4. Upon completion of the installation of the CN0235 Evaluation Software, the installer for the ADI SDP Drivers will execute.
   
   

   NOTE: It is recommended that you close all other applications before clicking “Next”. This will make it possible to update relevant system files without having to reboot your computer.

   
   
   
   
   

5. Press “Next” to set the installation location for the SDP Drivers.
   
   

   It is recommended that you install the drivers to the default directory path
   C:/Program Files/Analog Devices/SDP/Drivers

   
   
   

6. Press “Next” to install the SDP Drivers and complete the installation of all software. Click “Finish” when done.
   
   

• Step 1. Connect the EVAL-CN0235-SDPZ to EVAL-SDP-CB1Z(SDP Board) through the 120-pin SMD connector. Nylon hardware should be used to firmly secure the two boards, using the holes provided at the ends of the 120-pin connectors.
  
  
• Step 2. Do the jumper setting correctly based on desired setting for evaluation based on the jumper configuration provided on Jumper Configuration section.
  
  
• Step 3. Plug the mini-USB side of the cable into the mini-USB connector J1 on SDP Board and leave the other side of the cable(USB Type A) floated.
  
  
• Step 4. Connect the battery stack on J1 and J2 based on the number of cells configured by the jumper SEL0 and SEL1. Refer to the jumper configuration on General Setup section.
  
  
• Step 5. Plug in the wallwart and connect it to the barrel jack connector of the EVAL-CN0235-SDPZ .
  
  
• Step 6. Connect the USB-Type-A side of the USB cable to the PC.
  
  

1. Connect to SDP-B Board Button
   • When this button is pressed, the SDP-B Board makes a USB connection to the CN0235Board. A connection to the SDP-B Board must be made to use the software.
2. Device Selector
   • Selects the number of device to be activated.
3. Enable Real Time ADC Reads
   • When this button is checked, continuous data acquisition by the ADC will start.
4. Read ADC
   • When this button is clicked, a single capture read will be performed by the ADC.
5. Software Reset
   • When this button is clicked, all the configuration changes on the evaluation software will be revert back to its default state.
6. Hardware PD
   • Clicking this button will put AD7280A in to Full Power-Down mode, meaning, both the analog and digital circuitry of the AD7280A will be shut down, this in turn will only require 5uA maximum current. This button will also disable AD8280.
7. Software PD
   • . Clicking this button will put AD7280A in to Software Power-Down mode which requires only 3.8 mA maximum current. This button will also disable AD8280.
8. Software/Hardware PU
   • Clicking this button will power up the AD7280A when it’s coming from a software power down or hardware power down mode. This button will not enable the AD8280.
9. Enable/Disable AD8280
   • This button allows the user to enable or disable the secondary battery monitoring and protection system.
10. Self-Test AD8280
    • Executes the self test feature of AD8280.
11. Save Data to File
    • This button will execute a save data command to record the Voltage and Temperature reading of both devices in codes and volts format. The file may be saved as .txt or .xls.
12. Control Tabs
    • Voltage(Codes)/Voltage(Volts): Clicking either of these tabs brings out the voltage reading on each device's channel in front. These tabs shows the reading in either Codes or voltage format.
    • Temperature(Codes)/Temperature(Volts): Clicking either of these tabs brings out the temperature reading in front. These tabs shows the reading in either Codes or voltage format.
    • Configure AD7280A: Clicking this tab will bring the AD7280A configurations in front.
    • Advanced: Clicking this tab will bring out the advanced control for the device in front.
    • SDP Firmware Release Info Clicking this tab will bring out the firmware information currently installed in the PC.
13. AD7280A Configuration
    • All control tabs will be explained with more detail on the next section.
14. Warning indicators
    • AD7280 Alert: This is the primary monitor’s alert indicator. When the voltage or temperature reading exceeded the user defined thresholds from the AD7280A configuration, this LED will light up.
    • Under Voltage: This is one of the secondary monitor’s alert indicator. When the voltage or temperature reading exceeded the user defined floor threshold, this LED will light up.
    • Over Voltage: This is one of the secondary monitor’s alert indicator. When the voltage or temperature reading exceeded the user defined ceiling threshold, this LED will light up.

The voltage (code format) tab features two types of display namely the tanks and graph display:

Tank Display


The tank display provides the ADC code equivalent of the reading in bar-like comparison for each channel. This type of display provides the latest reading of the Lithium ion battery cells.

Graph Display


The graphical display tab provides the user with more features or options for the reading analysis.

1. Codes vs Sample graph
   • This plot provides the user with the behavior of each cells in a form of a line chart. This will enable the user to picture out the current behavior of the each lithium ion’s cell with time.
2. Latest channel code value
   • Similar with the tank display, this is the latest reading of the Lithium ion battery cells by the AD7280A.
3. Plot navigator
   • This allows the user to see the history of the battery reading.
4. Additional graph functions
   • The three additional acts as a pointer, plot view modifier and manual plot navigator respectively.

A right-click on the graph will give the user additional plot and data control features.

The voltage (volts format) tab features two types of display namely the tanks and graph display:

Tank Display


The tank display provides the ADC voltage equivalent of the reading in bar-like comparison for each channel. This type of display provides the latest reading of the Lithium ion battery cells.

Graph Display


The graphical display tab provides the user with more features or options for the measurement analysis.

1. Codes vs Sample graph
   • This plot provides the user with the behavior of each cells in a form of a line chart. This will enable the user to picture out the current behavior of the each lithium ion’s cell with time.
2. Latest channel code value
   • Similar with the tank display, this is the latest reading of the Lithium ion battery cells by the AD7280A.
3. Plot navigator
   • This allows the user to see the history of the battery reading.
4. Additional graph functions
   • The three additional acts as a pointer, plot view modifier and manual plot navigator respectively.

A right-click on the graph will give the user additional plot and data control features.

The Temperature (codes format) tab features two types of display namely the tanks and graph display:
Tank Display



The tank display provides the ADC code temperature reading of the thermistor in bar-like comparison for each channel. This type of display provides the latest reading of the Lithium ion battery cells.

Graph Display



The graphical display tab provides the user with more features or options for the reading analysis.

1. Codes vs Sample graph
   • This plot provides the user with the behavior of each cells in a form of a line chart. This will enable the user to picture out the current behavior of the each lithium ion’s cell with time.
2. Latest channel code value
   • Similar with the tank display, this is the latest reading of the Lithium ion battery cells by the AD7280A.
3. Plot navigator
   • This allows the user to see the history of the battery reading.
4. Additional graph functions
   • The three additional functions act as a pointer, plot view modifier and manual plot navigator respectively.

A right-click on the graph will give the user additional plot and data control features.

The temperature (volts format) tab features two types of display namely the tanks and graph display:

Tank Display


The tank display provides the ADC voltage equivalent of the thermistor reading in bar-like comparison for each channel. This type of display provides the latest reading of the Lithium ion battery cells.

Graph Display


The graphical display tab provides the user with more features or options for the measurement analysis.

1. Codes vs Sample graph
   • This plot provides the user with the behavior of each cells in a form of a line chart. This will enable the user to picture out the current behavior of the each lithium ion’s cell with time.
2. Latest channel code value
   • Similar with the tank display, this is the latest reading of the Lithium ion battery cells by the AD7280A.
3. Plot navigator
   • This allows the user to see the history of the battery reading.
4. Additional graph functions
   • The three additional acts as a pointer, plot view modifier and manual plot navigator respectively.

A right-click on the graph will give the user additional plot and data control features.

1. Force Update
   • This button updates the AD7280A configuration.
2. Voltage and Temperature Thresholds
   • Sets the desired ceiling and floor value for voltage and temperature, these values will determine when the warning indicators will turn on.
3. Conversion Averaging
   • Sets the AD7280’s conversion averaging feature where the acquisition and conversion of each cell input is repeated before the results are read back through SPI interface.
4. Acquisition Time
   • Sets the time required to acquire an input signal. The acquisition time is calculated using the following formula: tACQ = 10 x ((Rsource + R) x C). where:
   • R = 300 ohm, the resistance seen by the track and hold amplifier looking at the input.
   • C = 15pF, the sampling capacitance.
   • Rsource = any extra source impedance on the analog input between external capacitors and the input pins.
   • See AD7280A Datasheet page 21 for more details.
5. Self-Test AD7280A
   • This button initiates the self-test conversion of AD7280A, this feature allows the ADC and reference buffer’s operation to be verified.
     

     NOTE: The self-test conversion result varies between
     Code 970 and Code 990.

     
     
     
     
     

6. Cell Balance Outputs
   • Sets the cell balance output of AD7280A to drive the gate of external transistors providing 0V or 5V output with respect to the absolute amplitude of the negative terminal of the battery cell that is being balanced.
7. Cell Balance Timers
   • Sets the on-time of each Cell Balance output. The timer may be set from 0 minutes to 36.9 minutes with a 71.5second resolution. See AD7280A Datasheet page 27 for additional details and example configurations of the Cell balance timer.
8. Thermistor Term Resistor
   • Sets if the thermistor termination pin AUXterm will be used to terminate the thermistor inputs for each auxiliary ADC input of the AD7280A.
     

     NOTE: Due to settling time requirements, the thermistor termination resistor option should only be used when the acquisition time of AD7280A is set to the highest value which is 1.6us

The advanced tab allows the user to read/write to the AD7280A’s registers.

1. Dev0 and Dev1 Register Address
   • This the list of the register address of AD7280A and its current content or configuration.
2. Read Register
   • This button updates the register address array of both devices.
3. Write Register
   • Use this function to write a new value to a certain register of AD7280A.

Provides the SDP board firmware currently in use