X3100 Voltage Measurement Accuracy ® Application Note Description This test measures the accuracy of the celll voltage measurement circuits of the X3100. In the test, a known voltage is applied across each cell input of the X3100. The analog output voltage of the X3100 is measured for each cell. This value is compared to the input voltage. The collected data includes the values from three devices from three different lots. The data also includes tests at 0°C, 25°C and 50°C. Test Setup For this test, Vcc was held at 16V to prevent the device entering the sleep mode when testing cell voltages below 2V. In the test 4V was applied to all cells, except the cell being measured. The voltage was applied at 10mV intervals over four ranges. These input ranges were 1.5 to 1.7V, 2.5 to 2.7V, 3.5 to 3.7V and 4.0 to 4.2V. 16V For each cell and each applied voltage the output was recorded. This involves the changing of the analog multiplexer setting in the X3100. In gathering the data with this test, the output was sample. This procedure was used to reduce the effect of external noise on the test environment. Results The data for this test is available in raw form in an Excel spreadsheet. This spreadsheet includes data for each device, data for each lot, and data for all devices. Each set of data includes results for the three temperature settings and the four gain settings. The data was copied to other files for the purposes of generating graphs. The result summaries show the output error as a percentage. This error is provided for each of 3 lots as well as the combined data. Data is averaged, and standard deviation computed, from samples taken at three temperatures 0°C, 25°C and 50°C. VCELL1 AO + AN143.0 On the following charts, absolute error is the Output minus the Input, while the percent error is calculated as follows: X3100 + May 9, 2005 VCELL2 Output – Input Error = ----------------------------------------Input Overall Performance + + VCELL3 VCELL4 VSS The following set of graphs shows the performance of the X3100 over temperature and across three lots of three devices. The graphs will show the basic input/output curve, raw error, and error after correction for offset and gain. The below data shows that the X3100 output is accurate, with 3 standard deviations, to better than 2.5% error across all measured voltages. It also shows that over the key range of 2.5 to 4.2V, accuracies of better than 1% can be expected. These accuracies are not dependent on any calibration factors. FIGURE 1. CELL VOLTAGE MEASUREMENT 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2005. All Rights Reserved All other trademarks mentioned are the property of their respective owners. Application Note 143 HP6626 Power Supply X3100 + HP6626 Power Supply VCC VCELL1 + VRGP VCELL2 VRGC + VCELL3 VRGO + Keithley 2002 VCELL4 DMM VSS AO Keithley 2000 DMM SPI Serial Analog Select VCS1 VCS2 20.37 Ohm Keithley 236 Source Measurement Unit PC FIGURE 1. CHARACTERIZATION TEST SETUP 2 AN143.0 May 9, 2005 Application Note 143 Lot 1 Voltage Measurement Output Error - Cell 1 Lot 1 Voltage Output Error - Cell 1 (Lot 1) 3.0% 2.0% Output Error (V) 000.0E+0 -2.0E-3 1 1.5 2 2.5 3 3.5 4 4.5 1.0% -6.0E-3 0.0% -1.0% 1 -8.0E-3 -2.0% -10.0E-3 -3.0% -4.0E-3 1.5 2 2.5 3 3.5 4 4.5 Input Voltage -12.0E-3 Input Voltage 0degC 25degC 0degC Average 0degC +3 STD 0degC -3 STD 50degC FIGURE 2A. 25degC Average 25degC + 3STD 25degC -3 STD 50degC Average 50degC +3 STD 50degC -3 STD FIGURE 2B. FIGURE 2. INPUT TO OUTPUT VOLTAGE ERROR - CELL 1 Voltage Output Error - Cell 2 (Lot 1) Voltage Measurement Output Error - Cell 2 Lot 1 4.0% Output Error (V) 3.0% 15.0E-3 2.0% 10.0E-3 1.0% 5.0E-3 0.0% 000.0E+0 -1.0% 1 1.5 2 2.5 3 3.5 4 4.5 1.0 1.5 2.0 25degC 3.0 3.5 4.0 4.5 -2.0% Input Voltage (V) 0degC 2.5 Input Voltage 50degC 0degC Average 0degC +3STD 0degC -3STD 25degC Average 25degC +3STD 25degC -3STD 50degC Average 50degC +3STD 50degC -3STD FIGURE 3B. FIGURE 3A. FIGURE 3. INPUT TO OUTPUT VOLTAGE ERROR - CELL 2 3 AN143.0 May 9, 2005 Application Note 143 Lot 1 continued Voltage Output Error - Cell 3 (Lot 1) Voltage Measurement Output Error - Cell 3 Lot 1 Output Error (V) 2.0% 20.0E-3 1.5% 15.0E-3 1.0% 10.0E-3 0.5% 0.0% -0.5% 1 5.0E-3 000.0E+0 -5.0E-3 1 1.5 2 2.5 3 3.5 4 4.5 1.5 2 25degC 3 3.5 4 4.5 Input Voltage Input Voltage (V) 0degC 2.5 -1.0% 0degC Average 0degC +3STD 0degC -3STD 50degC FIGURE 4A. 25degC Average 25degC +3STD 25degC -3STD 50degC Average 50degC +3STD 50degC -3STD FIGURE 4B. FIGURE 4. INPUT TO OUTPUT VOLTAGE ERROR - CELL 3 Voltage Output Error - Cell 4 (Lot 1) Output Error (V) Voltage Measurement Output Error - Cell 4 Lot 1 25.0E-3 20.0E-3 15.0E-3 10.0E-3 5.0E-3 000.0E+0 1 1.5 2 2.5 3 3.5 4 4.5 1.4% 1.2% 1.0% 0.8% 0.6% 0.4% 0.2% 0.0% -0.2% 1 1.5 2 0degC 25degC 2.5 3 3.5 4 4.5 Input Voltage Input Voltage (V) 50degC 0degC Average 0degC +3STD 0degC -3STD FIGURE 5A. 25degC Average 25degC +3STD 25degC -3STD 50degC Average 50degC +3STD 50degC -3STD FIGURE 5B. FIGURE 5. INPUT TO OUTPUT VOLTAGE ERROR - CELL 4 4 AN143.0 May 9, 2005 Application Note 143 Lot 2 Voltage Output Error - Cell 1 (Lot 2) Output Error (V) Voltage Measurement Output Error - Cell 1 Lot 2 5.0E-3 000.0E+0 -5.0E-3 1 1.5 2 2.5 3 3.5 4 4.5 -10.0E-3 -15.0E-3 2.0% 1.5% 1.0% 0.5% 0.0% -0.5% 1 -1.0% -1.5% -2.0% 1.5 2 25degC 3 3.5 4 4.5 Input Voltage Input Voltage (V) 0degC 2.5 0degC Average 0degC +3 STD 0degC -3 STD 50degC FIGURE 6A. 25degC Average 25degC +3 STD 25degC -3 STD 50degC Average 50degC +3 STD 50degC -3 STD FIGURE 6B. FIGURE 6. INPUT TO OUTPUT VOLTAGE ERROR - CELL 1 Voltage Output Error - Cell 2 (Lot 2) Output Error (V) Voltage Measurement Output Error - Cell 2 Lot 2 10.0E-3 8.0E-3 6.0E-3 4.0E-3 2.0E-3 000.0E+0 -2.0E-3 1 1.00% 0.50% 0.00% 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 -0.50% 1.5 2 2.5 3 3.5 Input Voltage (V) 0degC 25degC 50degC 4 4.5 Input Voltage 0degC Average 0degC +3STD 0degC -3STD 25degC Average 25degC +3STD 25degC -3STD 50degC Average 50degC +3STD 50degC -3STD FIGURE 7B. FIGURE 7A. FIGURE 7. INPUT TO OUTPUT VOLTAGE ERROR - CELL 2 5 AN143.0 May 9, 2005 Application Note 143 Lot 2 (Continued) Voltage Output Error - Cell 3 (Lot 2) Output Error (V) Voltage Measurement Output Error - Cell 3 Lot 2 20.0E-3 15.0E-3 10.0E-3 5.0E-3 000.0E+0 -5.0E-3 1 -10.0E-3 2.0% 1.0% 0.0% -1.0% 1.5 2 2.5 3 3.5 4 4.5 1 1.5 2 25degC 3 3.5 4 4.5 -2.0% Input Voltage Input Voltage (V) 0degC 2.5 0degC Average 0degC +3STD 0degC -3STD 50degC FIGURE 8A. 25degC Average 25degC +3STD 25degC -3STD 50degC Average 50degC +3STD 50degC -3STD FIGURE 8B. FIGURE 8. INPUT TO OUTPUT VOLTAGE ERROR - CELL 3 Voltage Output Error - Cell 4 (Lot 2) Output Error (V) Voltage Measurement Output Error - Cell 4 Lot 2 20.0E-3 15.0E-3 10.0E-3 5.0E-3 000.0E+0 -5.0E-3 1 1.5 2 2.5 3 3.5 4 4.5 2.5% 2.0% 1.5% 1.0% 0.5% 0.0% -0.5% 1 -1.0% -1.5% 1.5 2 25degC 3 3.5 4 4.5 Input Voltage Input Voltage (V) 0degC 2.5 50degC 0degC Average 0degC +3STD 0degC -3STD 25degC Average 25degC +3STD 25degC -3STD 50degC Average 50degC +3STD 50degC -3STD FIGURE 9B. FIGURE 9A. FIGURE 9. INPUT TO OUTPUT VOLTAGE ERROR - CELL 4 6 AN143.0 May 9, 2005 Application Note 143 Lot 3 Voltage Output Error - Cell 1 (Lot 3) Output Error (V) Voltage Measurement Output Error - Cell 1 Lot 3 1.5% 1.0% 10.0E-3 0.5% 5.0E-3 0.0% 000.0E+0 -5.0E-3 1 1.5 2 2.5 3 3.5 4 4.5 -0.5% 1 1.5 2 2.5 3 3.5 4 4.5 -1.0% -10.0E-3 Input Voltage Input Voltage (V) 0degC 25degC 0degC Average 0degC +3 STD 0degC -3 STD 50degC FIGURE 10A. 25degC Average 25degC +3 STD 25degC -3 STD 50degC Average 50degC +3 STD 50degC -3 STD FIGURE 10B. FIGURE 10. INPUT TO OUTPUT VOLTAGE ERROR - CELL 1 Voltage Output Error - Cell 2 (Lot 3) Output Error (V) Voltage Measurement Output Error - Cell 2 Lot 3 10.0E-3 5.0E-3 000.0E+0 -5.0E-3 1 1.5 2 2.5 3 3.5 4 4.5 1.5% 1.0% 0.5% 0.0% -0.5%1.0 -1.0% -1.5% 1.5 2.0 2.5 3.0 3.5 4.0 4.5 Input Voltage -10.0E-3 Input Voltage (V) 0degC 25degC 50degC 0degC Average 0degC +3STD 0degC -3STD FIGURE 11A. 25degC Average 25degC +3STD 25degC -3STD 50degC Average 50degC +3STD 50degC -3STD FIGURE 11B. FIGURE 11. INPUT TO OUTPUT VOLTAGE ERROR - CELL 2 7 AN143.0 May 9, 2005 Application Note 143 Lot 3 (Continued) Voltage Output Error - Cell 3 (Lot 3) Output Error (V) Voltage Measurement Output Error - Cell 3 Lot 3 20.0E-3 10.0E-3 000.0E+0 1 1.5 2 2.5 3 3.5 4 4.5 -10.0E-3 2.0% 1.5% 1.0% 0.5% 0.0% -0.5% 1 -1.0% -1.5% 1.5 2 25degC 3 3.5 4 4.5 Input Voltage Input Voltage (V) 0degC 2.5 0degC Average 0degC +3STD 0degC -3STD 50degC FIGURE 12A. 25degC Average 25degC +3STD 25degC -3STD 50degC Average 50degC +3STD 50degC -3STD FIGURE 12B. FIGURE 12. INPUT TO OUTPUT VOLTAGE ERROR - CELL 3 Voltage Output Error - Cell 4 (Lot 3) Output Error (V) Voltage Measurement Output Error - Cell 4 Lot 3 15.0E-3 10.0E-3 5.0E-3 000.0E+0 -5.0E-3 1 1.5 2 2.5 3 3.5 -10.0E-3 4 4.5 2.0% 1.5% 1.0% 0.5% 0.0% -0.5% 1 -1.0% -1.5% 1.5 2 25degC 3 3.5 4 4.5 Input Voltage Input Voltage (V) 0degC 2.5 50degC 0degC Average 0degC +3STD 0degC -3STD FIGURE 13A. 25degC Average 25degC +3STD 25degC -3STD 50degC Average 50degC +3STD 50degC -3STD FIGURE 13B. FIGURE 13. INPUT TO OUTPUT VOLTAGE ERROR - CELL 4 8 AN143.0 May 9, 2005 Application Note 143 Combine All Lots Voltage Output Error - Cell 1 (Lot All) Output Error (V) Voltage Measurement Output Error - Cell 1 Lot All 5.0E-3 000.0E+0 -5.0E-3 1 1.5 2 2.5 3 3.5 4 4.5 -10.0E-3 -15.0E-3 2.0% 1.5% 1.0% 0.5% 0.0% -0.5% 1 -1.0% -1.5% -2.0% 1.5 2 2.5 3 3.5 4 4.5 Input Voltage Input Voltage (V) 0degC 25degC 0degC Average 0degC +3 STD 0degC -3 STD 50degC FIGURE 14A. 25degC Average 25degC +3 STD 25degC -3 STD 50degC Average 50degC +3 STD 50degC -3 STD FIGURE 14B. FIGURE 14. INPUT TO OUTPUT VOLTAGE ERROR - CELL 1 Voltage Output Error - Cell 2 (Lot All) Output Error (V) Voltage Measurement Output Error - Cell 2 Lot All 2.5% 2.0% 10.0E-3 1.5% 5.0E-3 0.5% 1.0% 0.0% -0.5% 1.0 000.0E+0 1 1.5 2 2.5 3 3.5 -5.0E-3 4 4.5 1.5 2.0 2.5 3.0 3.5 4.0 4.5 -1.0% -1.5% Input Voltage Input Voltage (V) 0degC 25degC 50degC 0degC Average 0degC +3STD 0degC -3STD 25degC Average 25degC +3STD 25degC -3STD 50degC Average 50degC +3STD 50degC -3STD FIGURE 15B. FIGURE 15A. FIGURE 15. INPUT TO OUTPUT VOLTAGE ERROR - CELL 2 9 AN143.0 May 9, 2005 Application Note 143 Combine All Lots (Continued) Voltage Output Error - Cell 3 (Lot All) Output Error (V) Voltage Measurement Output Error - Cell 3 Lot All 20.0E-3 15.0E-3 10.0E-3 5.0E-3 000.0E+0 -5.0E-3 1 -10.0E-3 1.5 2 2.5 3 3.5 4 4.5 2.0% 1.5% 1.0% 0.5% 0.0% -0.5% 1 -1.0% -1.5% 1.5 2 25degC 3 3.5 4 4.5 Input Voltage Input Voltage (V) 0degC 2.5 0degC Average 0degC +3STD 0degC -3STD 50degC FIGURE 16A. 25degC Average 25degC +3STD 25degC -3STD 50degC Average 50degC +3STD 50degC -3STD FIGURE 16B. FIGURE 16. INPUT TO OUTPUT VOLTAGE ERROR - CELL 3 Voltage Output Error - Cell 4 (Lot All) Voltage Measurement Output Error - Cell 4 Lot All 2.0% Output Error (V) 1.5% 20.0E-3 1.0% 15.0E-3 0.5% 0.0% -0.5% 1 10.0E-3 5.0E-3 -5.0E-3 1 1.5 2 2.5 3 3.5 4 4.5 -1.0% 000.0E+0 1.5 2 2.5 3 3.5 4 4.5 -1.5% Input Voltage Input Voltage (V) 0degC 25degC 50degC 0degC Average 0degC +3STD 0degC -3STD 25degC Average 25degC +3STD 25degC -3STD 50degC Average 50degC +3STD 50degC -3STD FIGURE 17B. FIGURE 17A. FIGURE 17. INPUT TO OUTPUT VOLTAGE ERROR - CELL 4 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 10 AN143.0 May 9, 2005