Application Note 1857 ISL94208EVZ (Rev B) User Guide Introduction This document is intended for use by individuals engaged in the development of hardware for a 4- to 6- series connected Li-ion battery pack using the ISL94208EVZ board. The evaluation kit provides full battery pack operation as well as offering the ability to read and write the ISL94208 registers, set thresholds and timer values, read cell voltages, control cell balancing outputs, and control the power FETs. The kit contains the following components: • ISL94208EVZ board. • ISL94208DB1EVZ cell balance daughter board. • ISL94208DB2EVZ cell balance daughter board. • GUI software for a PC running Windows XP. • A power supply interface board for connecting a single power source or a battery stack. Operation of the ISL94208EVZ board requires the use of a separate USB to I2C kit, part number “ISLI2C-KIT”. An optional link between the PC and the microcontroller BKGD connector is available from NXP (formerly Freescale) for monitoring and debugging the microcontroller code. Board Software” on page 10. For this use, a License agreement is not needed. • Set up a power supply for the board. The power supply should consist of a string of 4 to 6 batteries (see Figure 2), or a string of 4 to 6 resistors and a power supply, or 4 to 6 individual power supplies (see Figures 2, 3). To facilitate the power connections, the kit includes a power supply board. First Steps • If not already available, acquire the DeVaSys USB to I2C interface cable and module. This is available from Intersil in the ISLI2C-KIT. • Download the software from the Intersil website on the ISL94208 page. This is a zip file titled: “ISL94208EVZ Kit Software Release V2.10”. • Unzip the software files to a directory of your choice. • Prior to powering the ISL94208 (Rev B) board, install the USB to I2C board software and connect the DeVaSys board to the PC (see Appendix 1). However, do not connect the DeVaSys board to the ISL94208EVZ board, yet. This is just preparation of the test set up. With these pieces in place, the PC interface can then quickly be used to monitor the operation of the board, once power is applied. • If changes to the microcontroller code are desired, then it will be necessary to order a programming/debug module from NXP (formerly Freescale), part number, USBMULTILINKBDME. This kit also contains the Code Warrior development tools. To get the source code, contact Intersil and sign the license agreement. The programming/debug module is needed if the board is going to be calibrated. See “Installing The DeVaSys USB to I2C September 17, 2013 AN1857.0 FIGURE 1. ISL94208EVZ KIT BOARDS 1 The kit operates without using either cell balance board, however, if cell balancing is desired, then one of the two daughter boards should be connected before powering the board. Battery/Power Supply Connection When connecting battery packs or power supplies, use the recommended connections as shown in Figure 2. Make sure that the individual power supply voltages do not exceed the ISL94208 maximum input voltage differential of 5V per cell. If using a string of resistors to emulate the battery cells, then limit the power supply voltage, so that the resistor divider outputs do not exceed the ISL94208 input maximum ratings. It is recommended that, when using the resistor divider circuit (see Figure 2), the series resistors to be 100 or less and 2W minimum and balancing be disabled. Balancing should be disabled, because when activating the ISL94208 cell balance outputs, the current balance on the ISL94208 (Rev B) board lowers the voltage across balanced power supply resistor, while raising the voltage on all of the other series resistors. Turning on multiple cell balance outputs could then result in one or more of the VCELLN input voltages exceeding their maximum specified limit. CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas LLC 2013. All Rights Reserved Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries. All other trademarks mentioned are the property of their respective owners. Application Note 1857 6 CELLS 6 POWER SUPPLIES VCC VCC 7 VCELL6 6 CB6 VCELL5 V 5 CB5 VCELL4 V 4 CB4 VCELL3 V 3 CB3 VCELL2 2 1 VCC 7 VCELL6 4 CELLS VCC VCC 7 VCELL6 7 VCELL6 VCELL6 6 CB6 VCELL5 6 CB6 VCELL5 6 CB6 VCELL5 5 CB5 VCELL4 5 CB5 VCELL4 5 CB5 VCELL4 4 CB4 VCELL3 4 CB4 VCELL3 4 CB4 VCELL3 CB3 VCELL2 3 CB3 VCELL2 3 CB3 VCELL2 3 CB3 VCELL2 2 CB2 VCELL1 2 CB2 VCELL1 2 CB2 VCELL1 2 CB2 VCELL1 1 CB1 VCELL0 VSS 1 CB1 VCELL0 VSS 1 CB1 VCELL0 VSS 1 CB1 VCELL0 VSS 6 CB6 VCELL5 5 CB5 VCELL4 4 CB4 VCELL3 V 3 CB2 VCELL1 V CB1 VCELL0 VSS V 15V-27V 7 5 CELLS 6 SERIES RESISTORS V NOTES: 1. For the battery simulation resistors, use 100Ω/2W devices (maximum). If the divider resistors are more than 100Ω, then turning on the cell balance output can cause fluctuations in the cell input voltages that can violate the ISL94208 max specifications. If the series resistors are larger than 100Ω, we recommend removing the cell balance daughter board, to prevent accidental cell balancing, while monitoring the cell voltages and pack operation. 2. Before connecting the power supply to the board, check the voltages at the connector to verify that they are correct. 3. Multiple battery cells can be connected in parallel. FIGURE 2. BATTERY CONNECTION OPTIONS B+/PACK+ OPTIONAL 5 CELL CONNECTION 6 CELL CONNECTION TO LOAD + OR CHARGER + TO LOAD + OR CHARGER + CONNECTOR MALE ON BOARD (TOP VIEW) BAT- PACK- CONNECTOR MALE ON BOARD (TOP VIEW) TO LOAD BAT- CH- OPTIONAL THERMISTOR OR 50k POT (IF USED, REMOVE THERMISTOR ON BOARD) TO CHARGER - CONNECT TOGETHER TO ACTIVATE WAKE UP ON CHARGE CONNECT CIRCUIT PACK- TO LOAD - CHTO CHARGER - FIGURE 3. BATTERY CELL CONNECTION TO ISL94208 PCB 2 AN1857.0 September 17, 2013 Application Note 1857 Initial Testing USB to I2C interface Setup • Once the power supply connections are verified, make the PC connection to the board, via the USB port, the DeVaSys board, and the I2C cable. Before making this connection, make sure that the USB to I2C interface software is installed (see software installation guide). • Figure 4 shows a green board is connects between a power supply and the evaluation board. This multi-option board supports the connection a single power supply (using an on-board resistor divider), or separate power supplies for each input, or battery cells. • For this setup, connect a 20V supply to the power supply board with GND on J8 or J12 and the positive connected to J5 or J11. There should be a shunt on the “8-Cell” jumper. There is a jumper wire on the power supply board connecting the CELL8 input to the CELL6 input to provide a 6-cell source. • Before connecting the PC to the ISL94208EVZ board (through the USB to I2C interface) turn off the power supply and then plug the ISL94208EVZ board into the power supply board as shown in Figure 4. • Turn on the power supply. • Once power is turned on (or Li-ion cells are connected to the ISL94208 (Rev B) board), the Green RGO LED should light. Use meter 1 to measure the RGO voltage. It should read about 3.3V. • Connect the I2C cable from the DeVaSys board to the ISL94208EVZ board as shown in Figure 5. Use the 5- to 4-pin cable provided in the ISLI2C-KIT. CAUTION: The I2C interface ground pin connects with the Battery negative terminal. If a load connected between the Pack + and Pack - pins has the same ground reference as the PC, then both sides of the power FETs will be connected together through the PC and load ground leads. The Power FETs provide no interruption in the power path. Also, without proper care, there can be problems with ground loops or excess voltage conditions as a result of this connection. If the ground connections are a concern, see “I2C Isolation” on page 9. TO PC: RGO (ISL94208) DEVASYS: USB to I2C METER 1 AO (ISL94208) (3.3V) 15V-27V BATTERY/POWER SUPPLY I2C CONNECT Meter 2 (0-2.3V) BKGD CONNECT GND TO PC: JUMPER ON “8 CELL”POSITION NXP (FORMERLY FREESCALE) USB LINK USB to BKGD (OPTIONAL) POWER SUPPLY BOARD PROVIDES RESISTOR DIVIDER FOR GENERATING CELL VOLTAGES. USBLINK: USB to BKGD (Optional) FIGURE 4. ISL94208EVZ EVALUATION BOARD TEST CONNECTION 3 AN1857.0 September 17, 2013 Application Note 1857 The microcontroller on the board performs in a number of automatic functions. These are as follows: . ISL94208EVZ J8 SDA GND GND SCL FETs CABLE J29 5-PIN TO 5-PIN DeVaSys BOARD J2 1 1 USE 5-PIN TO 4-PIN CONNECTOR SUPPLIED WITH ISLI2C-KIT USB FIGURE 5. I 2C CONNECTION TO ISL94208 PCB 1. The cell inputs are monitored to high or low voltage. If any of the cell voltages go to high, the charge FET is turned off. If any of the cell voltages go to low, the discharge FET turns off. When voltage recovers from these excursions, back into the normal range, the FETs automatically turn on. 2. After an overcurrent or undervoltage condition, the microcontroller monitors the load and turns the FETs back on when the load is released. 3. The microcontroller monitors the temperature and turns off the cell balance and power FETs if temperature is to high or low. Testing the Board 4. The microcontroller performs cell balancing (once it is enabled through the GUI). • Power-up the board and start the GUI. The PC will be communicating with the microcontroller and the microcontroller will be communicating with the ISL94208. 5. The microcontroller monitors the cell voltages and reports these voltages to the GUI. • The GUI should power-up with some color. In this case, the FET controls should be GREEN and the indicators should all be green. If the GUI is all gray, then there is a communication problem (see the troubleshooting guide in the Appendix). • If the FET indicators remain RED after power-up, it is likely that at least one input voltage or the temperature is out of range. In normal operation, the cell voltages are scanned four times per second. If monitoring the AO voltage (as shown in Figure 4), the meter will not be stable, since it sees an output of a series of voltages. A scope can be used to monitor the AO output, or use the GUI to select a specific voltage or temperature. This operation by the GUI stops the microcontroller from automatically scanning the voltages and puts the selected voltage on AO constantly. Automatic scanning will not start again until the GUI selects Monitor “All” (see Figure 6). SELECT THE VOLTAGE TO MONITOR OR SELECT ALL. SELECT ALL TO START AUTO SCAN. FIGURE 6. ISL94208 GUI MONITOR TAB 4 AN1857.0 September 17, 2013 Application Note 1857 Over/UnderVoltage Testing • Test the overvoltage and undervoltage conditions by any of the following means. Monitoring the FET status using GUI, then a status update is required for the GUI to acquire the FET state. Setting an autoscan in the GUI is a quick way to check FET status. You can also use a meter to detect whether the ISL94208 is driving the FET gate or not. –If Li-ion cells are being used, discharge the pack until one or more of the cells reach undervoltage limit and the discharge FET turns off. Then, charge the pack until the FETs turn on again and continue charging until a cell overvoltage condition is reached. –If one power supply is being used, lower the voltage on power supply until one or more of the cells reach undervoltage limit and the discharge FET turns off. Then, increase the voltage until the FETs turn on again and continue increasing the voltage until a cell overvoltage condition is reached. –If seven power supplies are used, then simply decrease or increase any individual supply until the thresholds are reached and the FET turns off (or on). Overcurrent Testing • Testing the overcurrent settings with the ISL94208EVZ board is not easy without changing the values of the sense resistors on the board, because it was designed as a possible reference application. • As delivered, the ISL94208EVZ board provides a discharge sense resistor of 2.5mΩ and a charge sense resistor of 50mΩ. To get a discharge short circuit condition requires 80A. To get a discharge overcurrent condition requires a load of 40A. To get a charge overcurrent condition requires 2A. Changing both resistors to 0.5Ω provides a mechanism for easily testing the current thresholds. • To test the board in an application most likely requires that battery cells be used and there is a large load available. While the board was not extensively tested for these high load currents, the traces are short and wide enough to (theoretically) handle an overcurrent condition up to the 40A threshold. Cell Balance Testing • Testing the cell balance operation requires the use of Li-ion cells or individual power supplies for each cell, or it requires modifying the daughter board to use 1k cell balancing resistors instead of the 200Ω or 39Ω resistors on the standard boards. With 6 cells and VBAT = 20V, a string of 100 voltage divider resistors, and 39 cell balancing resistors, turning on one cell balance output drops the voltage on that cell to about 1V. At this voltage, the microcontroller puts the ISL94208 to sleep. • As a quick test of the cell balance circuits, use the GUI to turn on or off any combination of cell balance FETs using the CB6:CB1 check boxes in the GUI Cell Balance frame. • To test the software auto balance operation, start the cell balance test by first observing if the cell with the maximum cell voltage exceeds the cell with the minimum voltage by more than 30mV. If so, note the cell number of the maximum voltage cell. • Next, on the GUI, select the Cell Balance “Max #” to be “1”. This limits the balancing to only one cell (The one with the maximum voltage). • Monitor the cell balance LEDs on the board or the GUI to track the cell balance operation. On the GUI, use the CB refresh button (or start auto update) to update the indicators to show which cell is being balanced, it should be the maximum voltage cell. The board is set that the microcontroller balances for 2s, then turn off balancing for 2 second, then balance again. The maximum voltage cell is very close to the next highest voltage cell, or if there are many cells within a narrow voltage range, then any of these cells could be balanced, due to the accuracy of the microcontroller A/D converter. • For an application on, the balancing times may be too short. To set the balance timers for a different configuration, go to the “Pack Tab” in the GUI and change the cell balance on/off times. Setting 1s on and 1s off is the minimum setting for cell balancing, but 2s on, 2s off is the recommended minimum, only because an autoscan of 1s can cause confusion due to the asynchronous nature of cell balance and autoscan. • Next, select the Cell Balance “Max #” to be “2”. This limits the balancing to two cells (the highest two voltage cells). Again refresh the CB screen periodically to see the operation of the cell balance code. • Open the pack tab in the GUI and change some of the settings for overvoltage, undervoltage, or cell balance and re-test. Remember to click on “Write” to send the new parameters to the microcontroller. Sleep/Wake Testing The ISL94208 board can be put to sleep VIA commands from the PC listed as follow: There are three ways to put the ISL94208 into the sleep mode: 1. The easy way is to use the “Sleep” button below the register access frame of the GUI. 2. You can also use the GUI register access window to write an 80H to the ISL94208 register 4. 3. Lowering the voltage on any cell below 2.3V for 1 second, (default microcontroller software settings) causes the microcontroller to put the ISL94208 to sleep. In case, the operation turns off the ISL94208 RGO output and LED. To wake up the ISL94208 requires that the ISL94208 WKUP pin go below its wake up threshold. This can happen when a charger connects to the pack charge terminals or when a load is connected to the load terminals. • The charger connection works, because it pulls the charger negative terminal to about the ISL94208 VSS voltage, the same as would an unloaded charger. • The load connection works, because the load terminal is pulled high (in sleep mode, the power FETs are off, so the connection from the ISL94208 VSS pin to the Pack- pin is open.) • Circuitry on the board inverts this signal to pull the ISL94208 WKUP pin low to wake the device. 5 AN1857.0 September 17, 2013 Application Note 1857 10kΩ 200kΩ 4.99kΩ 100kΩ ISL94208 D1 2N7002 WKP0_L WKUP WKP0_C In the Configure Tab of the GUI, the WKPOL pin can be set to wake on a rising edge by checking the “WKUP Pin Active High” box. This sets the ISL94208 WKPOL bit to 1. When this option is selected, the ISL94208 wakens by a simulated microcontroller command using the WKP1 switch. VBACK 240kΩ There are three wake up push buttons. In the default setting, the ISL94208 WKPOL bit is 0. This forces a wake up when the WKUP pin goes low. The ISL94208EVZ board has one push button that pulls WKUP low, simulating the connection of a load (WKP0_L) and one that pulls WKUP low simulating the connection of a charger (WKP0_C). Pressing either button wakes the device. VBAT 15V The ISL94208 can be waken with real loads or chargers or by using the push buttons as shown in Figure 7. V CFET DFET VSS • When the ISL94208 wakes up it turns on the RGO output. This turns on the RGO LED. 0.47µF/35V DSC- CHRG- NOTES: 1. When the FETs are off, the WKP0_C button pulls the DSC- pin high, as would connection to a load. 2. The WKP0_C button brings the WKUP input to near VSS, as would connection to a load when the FETs are off. D1 prevents WKUP from going negative if the charger is at a much higher voltage than the cells. FIGURE 1. EXTERNAL WAKE UP CIRCUIT; WKPOL = 0 PACK+ 49.9kΩ 270kΩ WKP1 Polarity 0 - SIMULATED CHARGER CONNECT Polarity 1- SIMULATED μC WAKE Up Polarity 0- SIMULATED LOAD CONNECT FIGURE 7. ISL94208EVZ WAKE UP BUTTONS 49.9kΩ 49.9kΩ WKUP ISL94208 V 200kΩ µC CFET DFET VSS TUN ON, THEN OFF TO WAKE (>60ms HIGH TIME) DSC- CHRG- NOTES: 3. The components in blue wake the pack under control of the microcontroller, however these are not included on the board. 4. The WKP1 switch simulates a wake up by the microcontroller. FIGURE 1. EXTERNAL WAKE UP CIRCUIT; WKPOL = 1 6 AN1857.0 September 17, 2013 Application Note 1857 Additional Testing Pack Voltage Monitoring Further tests on the board will likely follow the lines of battery pack testing, which can become quite involved and be very specific to the application. Before setting up the tests, see the “GUI user Guide” for information on using the interface and see the “Microcode Reference Guide” for information about how the software works. The ISL94208EVZ has a circuit that is activated by the microcontroller to monitor the pack voltage directly. The input to the microcontroller is the pack voltage divided by 16 as shown in Figure 9. Other Board Features/Options PACK+ 100k Current Direction Detection The ISL94208EVZ board has a circuit to detect a charge or discharge current (see Figure 8). This circuit is designed to detect a small current flowing into or out of the pack. There are two main uses for the current direction detection circuit. The first is in power control. If the microcontroller does not see any current for a long period of time, it can put the pack hardware to sleep to extend battery life. Second, the cell balance routine is usually conducted only during a charge condition. To do this requires information that charge current is flowing. The current direction detectors are comparators only, when the current is high enough, the indicators go high. For charge current, the threshold is about 100mA, for discharge the threshold is about 800mA. These thresholds can be changed by replacing a resistor, but making the thresholds much lower may cause problems due to the op amp input offset. To change the discharge current detection threshold, change the value of R46 as shown in Figure 8 (a lower value lowers the current threshold). To change the charge current detection threshold, change the value of R40 (a lower value lowers the current threshold). 1.21M 365k 82k PACKV 16 TO μC A/D INPUT GND TO μC OUTPUT 49.9k GND FIGURE 9. DIRECT MONITOR OF THE PACK VOLTAGE The purpose of this circuit is to get an alternate reading of the pack voltage. Without this circuit, the pack voltage is determined by adding the individual cell voltages. Having a separate reading provides a “sanity check” that there are no gross cell measurement errors. PACK VOLTAGE MONITORING CIRCUIT RGO 1M 1M ISL28214 1 of 2 1k 1k R40 1M CHARGE INDICATOR TO μC FMMT619 GND BSS84DW CHARGE 0.05 0.005 DISCHARGE RGO 0.005 ISL28214 2 of 2 PACK VOLTAGE ENABLE(PIN 6) 1.8M 1k DISCHARGE INDICATOR TO μC R46 PACK VOLTAGE μC INPUT (PIN 12) FIGURE 10. ISL94208EVZ PACK VOLTAGE MONITORING CONNECTIONS FIGURE 8. USING OP AMP AND FETS TO DETECT CHARGE AND DISCHARGE CURRENT 7 AN1857.0 September 17, 2013 Application Note 1857 FET Drive Voltages Cell Balance Daughter Boards In the ISL94208EVZ board, a separate regulator provides the VFET1 and VFET2 reference voltages for the FET drive as shown in Figure 11. The ISL94208EVZ kit is provided with two daughter boards. The main board can be used without either board, but there will be no balancing. With no daughter boards, each VCELL input from the battery pack has a 1k series resistor and a 22nF filter resistor to ground. There are three main reasons for doing this: 1. In a simple configuration where VCFET2 connects to VCELL3 and VFET1 connects to VCELL2, the FET reference current is drawn primarily from CELL3 of the pack. Depending on the FET drive current, this can unbalance the pack by having different load characteristics across the cells. Using a regulator supplies current from the top of the battery stack, better maintaining balance. 2. When the voltage differential between VFET2 and VFET1 drops below approximately 2.8V, the FET drive has difficulty providing enough current to fully drive the FETs. This gets worse over-temperature. If the cell voltages drop below 2.3V each, then a direct connection of the VFET pins to the CELL pins can result in the FETs turning off (or not turning on.) Using the regulator, it is possible to maintain the FET drive current to cell voltages below 1.5V (6-cell pack). 3. By having the FET currents coming from the regulator it is possible to better maintain measurement accuracy, since there is no extra current flowing on an individual cell input. The 100k resistor on the 4.3V regulator does not allow enough current for the zener diode to regulate very well. Ideally, there would be a 3V zener and a 5.6k resistor (1mA zener current). However, this current significantly increases the pack current. By using a higher voltage zener and a larger resistor, a similar result is achieved with lower current. The actual differential voltage is not too significant. As long as the VFET pin limits are maintained, the differential does not drop below 2.8V The VFET regulator is one from Intersil. This is not necessary, but the regulator should be one that can be disabled so current is very low when the ISL94208 goes to sleep and turns off RGO. DB1 DAUGHTER BOARD The DB1 daughter board uses the internal balancing FETs on the ISL94208. When it is installed, balancing is not practical with 1k input series resistors, because the voltage drops would be to big. This would cause voltage measurement inaccuracies and the µC on the board will interpret this as either an open circuit condition or an undervoltage cell and put the board to sleep. To get around this, this daughter board places a 20Ω resistor in parallel with the 1k on the main board and increases the filter capacitor to 1µF. The filter on the CB pins should have the same time constant as the VCELL pins. The DB1 daughter board uses 200Ω balancing resistors. This is about the smallest resistor possible, without having trouble with voltage monitoring. When cell balance turns on between VCELLn and VCELLn-1, the voltage at VCELLn-1 increases by about 10% because of the 200Ω and 20Ω voltage divider between the cells, as shown in Figure 12. The DB1 daughter board has a balance current of about 16mA. 20 1µF 200 VCELLn CBn 0.1µF 20 VCELLn-1 1µF VSS ISL94208 VBAT ISL80136 ADJ EN 0.47µF 16V RGO 8.6V VFET2 300kΩ 50kΩ 4.3V 10µF 16V RGO VFET1 100kΩ VSS FIGURE 11. ISL94208 EXAMPLE ALTERNATIVE VFET POWER SUPPLY VCELL Input Schottky Diodes The ISL94208EVZ schematic shows five Schottky diodes on the inputs between VCELLn and CB(n+1). These were added to help deal with input surge currents during hot plugging the board into a battery pack. However, with input resistors larger than 100Ω, these components are not needed. 8 FIGURE 12. ISL94208DB1EVZ VCELL AND CB CONNECTION DB2 DAUGHTER BOARD The DB2 daughter board uses external balancing FETs. These are p-channel devices driven by the CB outputs. When this board is installed, the main board filters are left as-is with a 1k series resistor and 22nF capacitor to ground. The daughter board only adds the extra components for balancing as shown in Figure 13. Because the balance current does not pass through the input resistors, the monitored voltage does not change much when being balanced or not being balanced. However, there likely is some change. The DB2 balance circuit has about 100mA of balance current. Because of this, there will likely be some change in the source voltage (either a power supply or real cells). If the Li-Ion cell has 20mΩ internal resistance, then the 100mA of balance current will drop the measured voltage by 2mV. There will also be some error due to the current through 500k and two 1k resistors when the CB output turns on. This error is on the order of 7mV. AN1857.0 September 17, 2013 Application Note 1857 The DB2 board does not provide much heat sinking for the balance resistors. However, if five of the six balance outputs are on at the same time, there will be about 2W of power dissipated. This can cause the board to get hot. It is recommended that only a few cells be balanced at the same time, if the test extends over a long duration. ISOLATED I2C INTERFACE CONNECTION (MOTHERBOARD) 1k 22nF VCELLn 500k 1k CBn 39 1k VCELLn-1 22nF VSS FIGURE 13. ISL94208DB1EVZ VCELL AND CB CONNECTION BKGD CONNECTION FIGURE 14. ISL94208EVZ ISOLATED INTERFACE AND BKGD CONNECTIONS I2C Isolation Related Documentation In some test conditions ground connections can cause problems. This is because the I2C ground, power supply, load, and perhaps an oscilloscope may all connect to ground. This can cause problems ranging from grounding both sides of the power FETs (taking them out of the circuit) to creating ground loops or unexpected voltage potentials that can damage components. From Intersil The ISL 94208EVZ (Rev B) board provides an option for the addition of an isolation device on the I2C interface, the Analog Device ADuM1250. This allows the PC to monitor a battery pack that is connected to a load without the grounding problems that can arise from direct connect. To use this option, the device and a header needs to be installed on the board, then the DeVaSys board needs to connect to the JP3 connector as shown in Figure 14. • ISL94208DB1EVZ (rev B) daughter board schematics The DeVaSys board will need to connect with a 5- pin-to-5-pin point--to-point connector (pin 3 is not used, but the ADuM1250 uses the 3.3V supply provided by the DeVaSys board). SCHEMATICS/BILL OF MATERIAL • ISL94208EVZ (rev B) board schematics • ISL94208EVZ (rev B) board Bill of Material (BOM) • ISL94208DB1EVZ (rev B) daughter board BOM • ISL94208DB2EVZ (rev B) daughter board schematics • ISL94208DB2EVZ (rev B) daughter board BOM • MCB_PS_Z (rev B) board schematics • MCB_PS_Z (rev B) board BOM DOCUMENTS ISL94208 Microcode Reference Guide Microcontroller Options ISL94208 FN8306 Data Sheet. The BKGD connection on the ISL94208 board (see Figure 14) allows development of new or modified code for the NXP (formerly Freescale) MC9S08QG8 microcontroller, which is supplied on the board. ISL94208 Application Note. ISL94208 GUI User Guide DeVaSys USB-I2C software installation. From NXP (Formerly Freescale) MC9S08QG8 microcontroller data sheet. HCS08 Microcontrollers Family Reference Manual. 9 AN1857.0 September 17, 2013 Application Note 1857 Appendix 1 Installing The DeVaSys USB to I2C Board Software Select “Install from a list or specific location” and click “Next” a screen like the one shown will come up: Obtain the Devasys software along with the GUI code from the Intersil website on the ISL94208 page. Copy and extract the files from the “ISL94208 Eval Kit Software Release V2.10” zip file to the PC at whatever location is desired. Disconnect the DeVaSys board from the ISL94208 board. Then, plug in the DeVaSys board into the USB port. The following screen should pop up. Browse for the “Software” directory in the “ISL94208 Eval Kit SW and docs” folder then click “Next”. This should install the software, eventually bringing up the following screen: Select “Yes, this time only” and click “Next”. The following screen will come up: Click “Finish” and you’re done. 10 AN1857.0 September 17, 2013 Application Note 1857 Appendix 2 battery or source voltage to drop some voltage through the leads connecting the supply to the board. Communication Troubleshooting If the voltages changing during balance is a problem, then it is necessary to modify the code to turn off balance before taking a cell voltage reading, then turn it on again if conditions are still normal for balancing. The GUI Starts Up With All Items “Grayed Out”. 1. Check that the I2C cable is connected properly. 2. Check that the board is powered and that the RGO voltage is ~3.3V. 3. If the RGO voltage is not powered to the right voltage, move to the power supply troubleshooting section. 4. Make sure that the board drivers are installed correctly. On the DeVaSys USB to I2C interface board, there should be one red LED and one green LED lighted. 5. If the LEDs on the DeVaSys board are not on, make sure that the DeVaSys board is disconnected from the ISL94208 board when it is first plugged into the PC. 6. Use a scope to see that the I2C communication is correct at the board. Monitor the SCL and the SDA lines while initiating a read of the ISL94208 status register. Set the scope to single trigger on the falling edge of SCL. Power Supply Troubleshooting The RGO Does Not Have The Correct Voltage. 1. Check that the voltage on each of the input terminals are between 2.6V and 4.5V. 2. Check that there is no unexpected load on the RGO output. ISL94208 Troubleshooting The AO Voltages Are Reading Incorrectly At The AO Pin. The Cell Voltages Are Not Updated Correctly During Refresh. 1. In the refresh function there is a bug when less than 6 cells are connected. The auto-polling function works correctly, but for manual update of cells 3, 4, and 5, it is necessary to select the connected cell, click refresh, then select the displayed cell and click refresh. For example, in a 4-cell pack CELL1, CELL2, CELL5, and CELL6 inputs are used. To refresh the CELL3 voltage on the display requires selecting CELL5, clicking “Refresh”, and then selecting CELL3 and clicking “Refresh” again. After Writing A Configuration Value, And Doing A Refresh, The Value Returns To The Previous Setting. 1. There is a bug in the configuration write routine. It is supposed to set the Write enable bit prior to writing the new setting, but it does not do this properly. To ensure a proper operation, write “E0” to register 08H before changing the configuration value. This sets all write enable bits prior to write operation. 2. Another way that seems to work is to click on the Configuration Write button two times allowing enough time between clicks for the command to complete. Other Questions Forward any ISL94208EVZ questions to the Intersil Application Engineer at [email protected]. 1. Check that all cell balance outputs are off. 2. Make sure that there is minimal series resistance between the battery and the input pins of the ISL94208EVZ board and that the input voltages are between 2.6V and 4.3V. GUI Troubleshooting The Voltages Are Reading Incorrectly On The GUI. 1. Check that the RGO output is 3.3V. The GUI and microcontroller calculations assume the RGO voltage is 3.3V. Any variation translates directly into errors in the GUI screen value. 2. Power-down the board and stop the GUI. Power up the board and restart the GUI. This should clear any communication problems. 3. Turn off the cell balancing. When using the DB1 daughter board (internal balancing FETs) turning on the cell balancing causes current flows into the CBN pin and out the VCELL(n-1) pin. The current flowing out the VCELL(n-1) pin causes a voltage drop across the input resistor on one side of the cell measurement, but not the other. This can cause a measurement error of up to 200mV to 300mV. This change happens external to the ISL94208. Using the DB2 daughter board, the voltage changes less, because the FET is external and there is no balance current through the input series resistors, however, the balancing current can cause the 11 AN1857.0 September 17, 2013 12 Application Note 1857 FIGURE 15. ISL94208EVZ (REV B) SCHEMATIC (PAGE 1 of 4) AN1857.0 September 17, 2013 13 Application Note 1857 FIGURE 1. ISL94208EVZ (REV B) SCHEMATIC (PAGE 2 of 4) AN1857.0 September 17, 2013 14 Application Note 1857 FIGURE 16. ISL94208EVZ (REV B) SCHEMATIC (PAGE 3 of 4) AN1857.0 September 17, 2013 15 Application Note 1857 AN1857.0 September 17, 2013 FIGURE 16. ISL94208EVZ (REV B) SCHEMATIC (PAGE 4 of 4) Application Note 1857 TABLE 1. ISL94208 BILL OF MATERIALS (MAIN BOARD) Part Number ISL94208EVZREVBPCB Qty Units 1 ea Reference Designator DESCRIPTION PWB-PCB, ISL94208EVZ, REVB, ROHS GMK212BJ474KG-T 2 ea C12, C17 CAP, SMD, 0805, 0.47µF, 35V, 10%, X5R, ROHS H1044-00102-25V10-T 1 ea C3 CAP, SMD, 0402, 1000pF, 25V, 10%, X7R, ROHS H1044-00103-16V10-T 1 ea C15 CAP, SMD, 0402, 1µF, 16V, 10%, X7R, ROHS H1044-00104-16V10-T 1 ea C18 CAP, SMD, 0402, 0.1µF, 16V, 10%, X7R, ROHS H1045-00102-25V10-T 1 ea C16 CAP, SMD, 0603, 1000PF, 25V, 10%, X7R, ROHS H1045-00104-16V10-T 2 ea C13, C14 CAP, SMD, 0603, 0.1µF, 16V, 10%, X7R, ROHS H1045-00106-6R3V20-T 1 ea C8 CAP, SMD, 0603, 10µF, 6.3V, 20%, X5R, ROHS H1045-00223-50V10-T 7 ea C1, C2, C6, C9, C10, C19, C20 CAP, SMD, 0603, 0.022µF, 50V, 10%, X7R, ROHS H1045-DNP 0 ea C25, C26 CAP, SMD, 0603, DNP-PLACE HOLDER, ROHS H1046-00106-16V8020-T 1 ea C11, C30 CAP, SMD, 0805, 10µF, 16V, +80-20%, Y5V, ROHS H1065-DNP 2 ea C4, C5 CAP, SMD, 1206, DNP-PLACE HOLDER, ROHS H1082-00105-50V10-T 1 ea C7 CAP, SMD, 1210, 1µF, 50V, 10%, X7R, ROHS 1266 1 ea B- (Located right of J10) CONN-TERMINAL, TH, QUICK-FIT MALE TAB, 20.1x8.9, ROHS 22-28-8361-1X2 1 ea JP2 CONN-HEADER, 1X2, BRK-AWAY 1X36, 2.54mm, R/A, ROHS 22-28-8361-1X4 1 ea J29 CONN-HEADER, 1X4, BRK-AWAY 1X36, 2.54mm, R/A, ROHS 22-28-8361-1X7 1 ea J8 CONN-HEADER, 1X7, BRK-AWAY 1X36, 2.54mm, R/A, ROHS 67996-272HLF-2X3 1 ea JP1 CONN-HEADER, 2x3, BRKAWY 2X36, 2.54mm, VERTICAL, ROHS 929974-01-36-RK-1X7 1 ea J7 CONN-SOCKET, TH, 1X7, BRKAWY 1X36, 2.54mm, INSULATED, ROHS AZ23C3V3-7-F-T 1 ea D5 DIODE-ZENER, DUAL, SMD, SOT23, 3.3V, 300mW, ROHS BAT6203WE6327XT 4 ea D2, D4, D13, D15 DIODE-SCHOTTKY, SMD, 2P, SOD323, 40V, 20mA, ROHS MBR0540T1G-T 5 ea D26-D30 DIODE-SHOTTKEY RECTIFIER, SMD, SOD-123, 40V, 0.5A, ROHS MM3Z4V3T1G-T 1 ea D1 DIODE-ZENER, SMD, SOD-323, 4.3V, 200mW, ROHS MMSZ4702T1G-T 1 ea D25 DIODE-ZENER, SMD, 2P, SOD-123, 15V, 500mW, ROHS MMSZ4705T1G-T 2 ea D16, D23 DIODE-ZENER, SMD, 2P, SOD-123, 18V, 500mW, ROHS MMSZ4713T1G-T 1 ea D3 DIODE-ZENER, SMD, 2P, SOD-123, 30V, 500mW, ROHS LNJ326W83RA-T 1 ea D12 LED, SMD, 0603, GREEN, 2.05V, 17mcd, 10mA, ROHS ISL28214FUZ 1 ea U2 IC-DUAL OP AMP, RRIO, 8P, MSOP, ROHS ISL80136IBEAJZ 1 ea U6 IC-40V LDO ADJ. LINEAR REGULATOR, 8P, EPSOIC, ROHS ISL94208IRZ 1 ea U1 IC-MULTI-CELL LI-ION BATTERY, 32P, QFN, 5X5, ROHS MC9S08QG8CFFE 1 ea U3 IC-MCU, FLASH, 8Kx8, 10MHz, 16P, QFN, ROHS 2N7002-7-F-T 1 ea Q3 TRANSISTOR, N-CHANNEL, 3LD, SOT-23, 60V, 115mA, ROHS BC817-40W-7-T 1 ea Q13 TRANSISTOR-NPN, SMD, 3P, SOT-323, 45V, 500mA, ROHS BSS8402DW-7-F-T 1 ea Q5 TRANSIST-MOS, P-CHANNEL/N-CHANNEL, 6P, SOT-363, 200mW, ROHS BSS84DW-7-F-T 1 ea Q4 TRANSIST, DUAL P-CHANNEL, 6P, SOT-363, -50V, -130mA, ROHS FMMT619TA-T 1 ea Q1 TRANSISTOR, NPN, SOT23, 50V, 2A, ROHS IRF1404SPBF 2 ea Q2, Q12 TRANSIST-MOS, N-CHANNEL, TH, D2-PAK, 40V, 162A, ROHS IRF7469PBF 2 ea Q14, Q15 TRANSISTOR-MOS, SMPS, 8P, SOIC, 40V, 9A, ROHS CSNL20.0051%R-T 2 ea R52, R53 RES-CURR SENSE, SMD, 2512, 0.005ohm, 2W, 1%, MF, ROHS CSRN20.051%I-T 1 ea R50 RES-CURR SENSE, SMD, 2512, 0.05ohm, 2W, 1%, TF, ROHS H2510-01001-1/16W1-T 3 ea R34, R40, R46 RES, SMD, 0402, 1k, 1/16W, 1%, TF, ROHS H2510-01002-1/16W1-T 3 ea R93 RES, SMD, 0402, 10k, 1/16W, 1%, TF, ROHS H2510-01003-1/16W1-T 3 ea R2, R36, R66 RES, SMD, 0402, 100k, 1/16W, 1%, TF, ROHS H2510-01004-1/16W1-T 5 ea R26, R27, R42, R43, R64 RES, SMD, 0402, 1MEG, 1/16W, 1%, TF, ROHS H2510-01005-1/16W1-T 1 ea R48 RES, SMD, 0402, 10M, 1/16W, 1%, TF, ROHS H2510-01204-1/16W1-T 1 ea R49 RES, SMD, 0402, 1.2MEG, 1/16W, 1%, TF, ROHS 16 AN1857.0 September 17, 2013 Application Note 1857 TABLE 1. ISL94208 BILL OF MATERIALS (MAIN BOARD) (Continued) H2510-01804-1/16W1-T 1 ea R75 RES, SMD, 0402, 1.8M, 1/16W, 1%, TF, ROHS H2510-02003-1/16W1-T 3 ea R94 RES, SMD, 0402, 200k, 1/16W, 1%, TF, ROHS H2510-02703-1/16W1-T 3 ea R92 RES, SMD, 0402, 270k, 1/16W, 1%, TF, ROHS H2510-03003-1/16W1-T 3 ea R84 RES, SMD, 0402, 300k, 1/16W, 1%, TF, ROHS H2510-03653-1/16W1-T 1 ea R6 RES, SMD, 0402, 365k, 1/16W, 1%, TF, ROHS H2510-04642-1/16W1-T 1 ea R38 RES, SMD, 0402, 46.4k, 1/16W, 1%, TF, ROHS H2510-04701-1/16W1-T 4 ea R3, R4, R81, R82 RES, SMD, 0402, 4.7k, 1/16W, 1%, TF, ROHS H2510-04991-1/16W1-T 2 ea R47, R95 RES, SMD, 0402, 4.99k, 1/16W, 1%, TF, ROHS H2510-04992-1/16W1-T 2 ea R54, R91 RES, SMD, 0402, 49.9k, 1/16W, 1%, TF, ROHS H2510-049R9-1/16W1-T 1 ea R67 RES, SMD, 0402, 49.9Ω, 1/16W, 1%, TF, ROHS H2510-08202-1/16W1-T 1 ea R51 RES, SMD, 0402, 82k, 1/16W, 1%, TF, ROHS H2511-01000-1/10W1-T 4 ea R28, R29, R33, R35 RES, SMD, 0603, 100Ω, 1/10W, 1%, TF, ROHS H2511-01001-1/10W1-T 0 ea DNP - R8, R9 RES, SMD, 0603, 1k, 1/10W, 1%, TF, ROHS H2511-01001-1/10W1-T 10 ea R7, R10, R11, R13, R15, R17, R19, R21, R41, R62. RES, SMD, 0603, 1k, 1/10W, 1%, TF, ROHS H2511-01002-1/10W1-T 2 ea R45, R103 RES, SMD, 0603, 10k, 1/10W, 1%, TF, ROHS H2511-01004-1/10W1-T 1 ea R65 RES, SMD, 0603, 1M, 1/10W, 1%, TF, ROHS H2511-02403-1/10W1-T 1 ea R5 RES, SMD, 0603, 240k, 1/10W, 1%, TF, ROHS H2511-02493-1/10W1-T 1 ea R39 RES, SMD, 0603, 249k, 1/10W, 1%, TF, ROHS H2511-04990-1/10W1-T 1 ea R37 RES, SMD, 0603, 499Ω, 1/10W, 1%, TF, ROHS H2511-04991-1/10W1-T 1 ea R23 RES, SMD, 0603, 4.99k, 1/10W, 1%, TF, ROHS H2511-05110-1/10W1-T 1 ea R1 RES, SMD, 0603, 511Ω, 1/10W, 1%, TF, ROHS H2511-DNP 0 ea R83 RES, SMD, 0603, DNP-PLACE HOLDER, ROHS H2512-00270-1/8W1-T 1 ea R63 RES, SMD, 0805, 27Ω, 1/8W, 1%, TF, ROHS FSMSMTR-T 3 ea S1, S2, S3 SWITCH-TACTILE, SMD, 6X3.5, 12V, 0.05A, SPST-NO, ROHS DNP 0 ea C28 DO NOT POPULATE OR PURCHASE DNP 0 ea J10, J42 DO NOT POPULATE OR PURCHASE DNP 0 ea JP3 (22-23-2051) DO NOT POPULATE OR PURCHASE DNP 0 ea R76 DO NOT POPULATE OR PURCHASE DNP 0 ea U4 (ADUM1250ARZ) DO NOT POPULATE OR PURCHASE DNP 0 ea a) CSns, DSns, CFET, DFET, TMPI, RGO, RGC, AO, DO NOT POPULATE OR PURCHASE DNP 0 ea b) SCL, SDA, PSCL, PSDA, VMon, DO NOT POPULATE OR PURCHASE WKUP DNP 0 ea c) Dgate, TEMP3V, Pack-DSC, Pack-CHG, A2DIN DNP 0 ea d) µCP1, µCP2, ENI, ENPV, CHI, DO NOT POPULATE OR PURCHASE DCI, PV 17 DO NOT POPULATE OR PURCHASE AN1857.0 September 17, 2013 Application Note 1857 TABLE 2. ISL94208 BILL OF MATERIALS (DAUGHTER BOARD 1) PART NUMBER QTY UNITS REFERENCE DESIGNATOR DESCRIPTION ISL94208DB1EVZREVBPCB 1 ea PWB-PCB, ISL94208DB1EVZ, REVB, ROHS H1045-00104-50V10-T 6 ea C21-C24, C27, C29 CAP, SMD, 0603, 0.1µF, 50V, 10%, X7R, ROHS H1045-00105-50V10-T 6 ea C31-C37 CAP, SMD, 0603, 1µF, 50V, 10%, X7R, ROHS 929834-01-36-RK-1X13 1 ea J17 CONN-HEADER, TH, 1x13, BRKAWY 1x36, 2.54mm, ROHS 929834-01-36-RK-1X7 1 ea J9 CONN-HEADER, TH, 1x7, BRKAWY 1x36, 2.54mm, ROHS LNJ826W83RA-T 6 ea D6-D11 LED, SMD, 0603, ORANGE, 19mcd, 5mA, 1.9V, 620nm, ROHS H2510-07500-1/16W1-T 6 ea R56-R61 RES, SMD, 0402, 750Ω, 1/16W, 1%, TF, ROHS H2515-02000-1W5-T 6 ea R85-R90 RES, SMD, 2512, 200Ω, 1W, 5%, TF, ROHS H2511-00200-1/10W1-T 4 ea R96-R102 RES, SMD, 0603, 20Ω, 1/10W, 1%, TF, ROHS TABLE 3. ISL94208 BILL OF MATERIALS (DAUGHTER BOARD 2) PART NUMBER QTY UNITS REFERENCE DESIGNATOR DESCRIPTION ISL94208DB2EVZREVBPCB 1 ea PWB-PCB, ISL94208DB2EVZ, REVB, ROHS 929834-01-36-RK-1X13 1 ea J24 CONN-HEADER, TH, 1x13, BRKAWY 1x36, 2.54mm, ROHS 929834-01-36-RK-1X7 1 ea J11 CONN-HEADER, TH, 1x7, BRKAWY 1x36, 2.54mm, ROHS LNJ826W83RA-T 6 ea D17-D22 LED, SMD, 0603, ORANGE, 19mcd, 5mA, 1.9V, 620nm, ROHS MMBT3906K-T 6 ea Q6-Q11 TRANSISTOR, PNP, 3P, SOT-23, -40V, -200mA, ROHS H2510-01001-1/16W1-T 6 ea R12, R14, R16, R18, R20, R22 RES, SMD, 0402, 1k, 1/16W, 1%, TF, ROHS H2510-04993-1/16W1-T 6 ea R73, R74, R77-R80 RES, SMD, 0402, 499k, 1/16W, 1%, TF, ROHS H2510-07500-1/16W1-T 6 ea R24, R25, R30, R31, R32, R44 RES, SMD, 0402, 750Ω, 1/16W, 1%, TF, ROHS H2515-00390-1W1-T 6 ea R55, R68-R72 RES, SMD, 2512, 39Ω, 1W, 1%, TF, ROHS Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that the Application Note or Technical Brief is current before proceeding. For information regarding Intersil Corporation and its products, see www.intersil.com 18 AN1857.0 September 17, 2013