Electronic Components Datasheet Search |
|
BQ2060A Datasheet(PDF) 3 Page - Texas Instruments |
|
|
BQ2060A Datasheet(HTML) 3 Page - Texas Instruments |
3 / 46 page Functional Description General Operation The bq2060A determines battery capacity by monitoring the amount of charge input or removed from a recharge- able battery. In addition to measuring charge and dis- charge, the bq2060A measures battery voltage, tempera- ture, and current, estimates battery self-discharge, and monitors the battery for low-voltage thresholds. The bq2060A measures charge and discharge activity by monitoring the voltage across a small-value series sense resistor between the battery’s negative terminal and the negative terminal of the battery pack. The available battery charge is determined by monitoring this voltage and correcting the measurement for environmental and operating conditions. Figure 1 shows a typical bq2060A-based battery-pack application. The circuit consists of the LED display, voltage and temperature measurement networks, EEPROM connections, a serial port, and the sense resis- tor. The EEPROM stores basic battery-pack configura- tion information and measurement-calibration values. The EEPROM must be programmed properly for bq2060A operation. Table 9 shows the EEPROM mem- ory map and outlines the programmable functions avail- able in the bq2060A. The bq2060A accepts an NTC thermistor (Semitec 103AT) for temperature measurement. The bq2060A uses the thermistor temperature to monitor bat- tery-pack temperature, detect a battery full-charge con- dition, and compensate for self-discharge and charge/dis- charge battery efficiencies. Measurements The bq2060A uses a fully differential, dynamically bal- anced voltage-to-frequency converter (VFC) for charge measurement and a sigma delta analog-to-digital con- verter (ADC) for battery voltage, current, and tempera- ture measurement. Voltage, current, and temperature measurements are made every 2–2.5 seconds, depending on the bq2060A operating mode. Maximum times occur with compen- sated EDV, mWh mode, and maximum allowable dis- charge rate. Any AtRate computations requested or scheduled (every 20 seconds) may add up to 0.5 seconds to the time interval. Charge and Discharge Counting The VFC measures the charge and discharge flow of the battery by monitoring a small-value sense resistor between the SR1 and SR2 pins as shown in Figure 1. The VFC measures bipolar signals up to 250mV. The bq2060A detects charge activity when VSR =VSR2 – VSR1 is positive and discharge activity when VSR =VSR2 –VSR1 is negative. The bq2060A continuously integrates the signal over time using an internal counter. The fundamental rate of the counter is 6.25 µVh. Offset Calibration The bq2060A provides an auto-calibration feature to can- cel the voltage offset error across SR1 and SR2 for maxi- mum charge measurement accuracy. The calibration rou- tine is initiated by issuing a command to ManufacturerAccess(). The bq2060A is capable of auto- matic offset calibration down to 6.25 µV. Offset cancellation resolution is less than 1 µV. Digital Filter The bq2060A does not measure charge or discharge counts below the digital filter threshold. The digital fil- ter threshold is programmed in the EEPROM and should be set sufficiently high to prevent false signal de- tection with no charge or discharge flowing through the sense resistor. Voltage While monitoring SR1 and SR2 for charge and discharge currents, the bq2060A monitors the battery-pack poten- tial and the individual cell voltages through the VCELL1–VCELL4 pins. The bq2060A measures the pack voltage and reports the result in Voltage(). The bq2060A can also measure the voltage of up to four series ele- ments in a battery pack. The individual cell voltages are stored in the optional Manufacturer Function area. The VCELL1–VCELL4 inputs are divided down from the cells using precision resistors, as shown in Figure 1. The maximum input for VCELL1–VCELL4 is 1.25V with re- spect to VSS. The voltage dividers for the inputs must be set so that the voltages at the inputs do not exceed the 1.25V limit under all operating conditions. Also, the di- vider ratios on VCELL1–VCELL2 must be half of that of VCELL3–VCELL4. To reduce current consumption from the battery, the CVON output may used to connect the divider to the cells only during measurement period. CVON is high impedance for 250ms (12.5% duty cycle) when the cells are measured, and driven low otherwise. (See Table 1.) The SRC input of the bq2060A measures battery charge and discharge current. The SRC ADC input converts the current signal from the series sense resistor and stores the result in Current(). The full-scale input range to SBC is limited to ±250mV as shown in Table 2. 3 bq2060A |
Similar Part No. - BQ2060A |
|
Similar Description - BQ2060A |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |