* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download How to Operate bq20z7x/8x/9x Fuel Gauge and
Survey
Document related concepts
Variable-frequency drive wikipedia , lookup
Voltage optimisation wikipedia , lookup
Alternating current wikipedia , lookup
Control system wikipedia , lookup
Electric battery wikipedia , lookup
Buck converter wikipedia , lookup
Mains electricity wikipedia , lookup
Voltage regulator wikipedia , lookup
Distribution management system wikipedia , lookup
Automatic test equipment wikipedia , lookup
Rechargeable battery wikipedia , lookup
Switched-mode power supply wikipedia , lookup
Transcript
Application Report SLUA608 – August 2011 How to Operate bq20z7x/8x/9x Fuel Gauge and bq24707/25/26 Charger Without Host Controller Tahar Allag/Wang Li ...................................................................................... PMP BMS Battery Charge ABSTRACT The bq24707/26/25 chargers and the bq20z7x/8x/9x gas gauges are both SBS-compliant integrated circuits. In this application report, both of these chargers and gas gauges are used together as a nonhost-control, battery charging system. An external regulator, TPS7A49xx, is added to the system to prevent shutting down the system during a deeply discharged state of the battery cells. It provides a wake-up current to charge the discharged battery cells and power up the system. This document describes the system in detail and provides the test results. 1 Descriptions 1.1 bq24707/25/26 The bq24707/25/26 is a highly efficient, synchronous, battery-charger family designed for multichemistry batteries. The integrated circuit (IC) operates as a slave, where it receives control inputs externally from the embedded controller host through the SMBus interface. The SMBus-controlled input current, charge voltage, and charge current provide high regulation accuracies that can be programmed externally using a system power management microcontroller. In this application report, the gas gauge is used to operate as a master, and the charger receives the controlled input from the gas gauge through the SMBus. 1.2 bq20z7x/8x/9x The bq20z7x/8x/9x, SBS-compliant gas gauge IC, incorporating patented Impedance Track™ technology, is designed for battery-pack or in-system installation. It measures and maintains an accurate record of available charge in Li-ion or Li-polymer batteries using its integrated high-performance analog peripherals. It monitors capacity change, battery impedance, open-circuit voltage, and other critical parameters of the battery pack, and reports the information to the system host controller over a SMBus. 1.3 TPS7A49xx The TPS7A49xx is a series of devices that is positive, high-voltage (up to 36 V), ultralow-noise, linear regulator that is capable of sourcing a load of 150 mA. It is suited for post dc-dc converter regulation. It has an option to adjust the output voltage from 1.194 V to 33 V using external resistors tied in series with the output and the feedback pin. One of the primary uses of this linear regulator is to provide ultralow noise on a voltage rail at a fixed output voltage. In this application report, the TPS7A49xx is used to revive the deeply discharged battery cell to allow proper operation of the gas gauges and the entire system. 2 Implementations The charge IC (bq24707/25/26) and gas gauge IC (bq20z7x/8x/9x) are both SBS compliant. The charger IC operates as a slave. Control input is received from the gas gauge IC through the SMBus. The gas gauge IC operates as master with broadcasts enabled. It broadcasts the ChargeCurrent() and ChargeVoltage() command to the charger IC. The ChargeCurrent() register address is 0x14 and the ChargerVoltage() register address is 0x15. When the charger IC gets the two commands, it starts the Impedance Track is a trademark of Texas Instruments. SLUA608 – August 2011 Submit Documentation Feedback How to Operate bq20z7x/8x/9x Fuel Gauge and bq24707/25/26 Charger Without Host Controller Copyright © 2011, Texas Instruments Incorporated 1 Implementations www.ti.com charger. In this system, no extra host controller is required for the charger IC. It saves the total cost of the total system software resource. However, an external linear regulator is required for keeping the system on during low state of charge of the battery cells. When the battery cells are deeply discharged, the linear regulator provides a wake-up current to bring the cell voltage up and power up the bq20z90/80/70 gas gauge. This application report gives an example of using bq24707 and bq20z90 together as a nonhost-control, battery-charging system solution with a combination of linear regulator TPS7A49xx. The bq24726 evaluation module (HPA3558), and the bq20z90 evaluation module (HPA155) are used for this demonstration. Figure 1. bq24726, TPS7A49xx and bq20z90 EVMs Constitute a Nonhost-Control, SMBus Charger System Figure 1 shows a two-EVM connection for the nonhost control SMBus charger system. The following steps show how the Figure 1 test setup can be constructed. Step 1. bq24726EVM Setup: 2 How to Operate bq20z7x/8x/9x Fuel Gauge and bq24707/25/26 Charger Without Host Controller Copyright © 2011, Texas Instruments Incorporated SLUA608 – August 2011 Submit Documentation Feedback Test Result www.ti.com 1. 2. 3. 4. Connect ACDET to BAT in JP1. Connect VCC to BAT in JP3. Connect EXT to DPM in JP2. The 3.3-V output of the TPS7A4901 must be connected to the J3-3V3 of the bq24726EVM. Step 2. bq20z90EVM Configuration: 1. Enable the bcast bit in DF. This bit is in one of the Operation CFG DF locations. 2. Ensure that HPE or CPE bits are set in the in DF because the charger does not use PEC. 3. Add a short jumper between TB4-SYS PRES and TB3-GND. 4. Add three battery cells in series among 1N, 1P, 2P, and 3P. Also, short jumper between 3P and 4P. Step 3. The TPS7A4901 needs to be adjusted to output 3.3 V and 6 V. Then connect bq24726, bq20z90, TPS7A4901, and the power supply together as follows: 1. Connect input power supply only to bq24726EVM J1, and adjust the power supply from 18 V to 24 V. 2. Connect the power supply to the input of the TPS7A4901EVM. 3. Connect the 3.3-V output of the TPS7A4901 to J3-3V3 on the bq24726EVM. 4. Connect the other 6-V TPS7A4901 to a Schottky diode; the output of the diode must be connected to Pack+-TB4. 5. Connect the SMbus wires between the bq24765EVM and the bq20z80EVM. bq24726EVM J4-GND J4-SCL J4-SDA bq20z90EVM J1-Vss J1-SMBC J1_SMBB 6. Connect the bq24726EVM’s BAT output to bq20z90 EVM’s pack termination. bq24726EVM J10-GND J10-BAT 3 bq20z90EVM TB4-PACK– TB1-PACK+ Test Result A 19-V power supply is used to supply both the bq24726 charger and the TPS7A49 regulators. Three battery cells are connected in series to the gas gauge bq29z726EVM. Figure 2 shows the controlled signals; the controlled battery voltage is regulated to the desired level. SLUA608 – August 2011 Submit Documentation Feedback How to Operate bq20z7x/8x/9x Fuel Gauge and bq24707/25/26 Charger Without Host Controller Copyright © 2011, Texas Instruments Incorporated 3 Test Result www.ti.com Figure 2. SMBUS Control Signal With a Regulated V-bat and System Output Figure 3 shows the test result for the combined gas gauge with the charger but without the additional 3.3-V and 6-V regulator. As the battery voltage drops below 6 V, the gas gauge shuts down. This causes the entire system to fail because no control signal is sent from the bq20x90 to the charger. To avoid such scenarios, an additional regulator is added to the system to prevent the system from failing during deeply discharged battery cells. Also the bq24726 requires a 3.3-V reference source; another 3.3-V regulator is added as shown in Figure 1. 4 How to Operate bq20z7x/8x/9x Fuel Gauge and bq24707/25/26 Charger Without Host Controller Copyright © 2011, Texas Instruments Incorporated SLUA608 – August 2011 Submit Documentation Feedback Test Result www.ti.com Figure 3. Test Result for System Without TPS7A49 6-V Regulator Conclusion This application report explains the use of a TI nonhost-control, SMBus, battery-charging system solution. This solution consists of using the bq24707/25/26 and bq20z90/80/70 together with a combination of linear regulator TPS7A49xx. References 1. How to Operate Fuel Gauge bq20z7x/8x/9x and the SMBus-Like Smart Chargers bq24747/765 Without a Host Controller application report (SLUA533) 2. TPS7A49xx, +36V, +150mA, Ultralow-Noise, Positive LIinear Regulator data sheet ( SBVS121) 3. bq20z80EVM-001 SBS1.1 Impedance Track™ Technology Enabled Battery Management Solution Evaluation Module user's guide (SLUU234) SLUA608 – August 2011 Submit Documentation Feedback How to Operate bq20z7x/8x/9x Fuel Gauge and bq24707/25/26 Charger Without Host Controller Copyright © 2011, Texas Instruments Incorporated 5 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional restrictions. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. TI products are not authorized for use in safety-critical applications (such as life support) where a failure of the TI product would reasonably be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement specifically governing such use. Buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of TI products in such safety-critical applications, notwithstanding any applications-related information or support that may be provided by TI. Further, Buyers must fully indemnify TI and its representatives against any damages arising out of the use of TI products in such safety-critical applications. TI products are neither designed nor intended for use in military/aerospace applications or environments unless the TI products are specifically designated by TI as military-grade or "enhanced plastic." Only products designated by TI as military-grade meet military specifications. Buyers acknowledge and agree that any such use of TI products which TI has not designated as military-grade is solely at the Buyer's risk, and that they are solely responsible for compliance with all legal and regulatory requirements in connection with such use. TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products are designated by TI as compliant with ISO/TS 16949 requirements. Buyers acknowledge and agree that, if they use any non-designated products in automotive applications, TI will not be responsible for any failure to meet such requirements. Following are URLs where you can obtain information on other Texas Instruments products and application solutions: Products Applications Audio www.ti.com/audio Communications and Telecom www.ti.com/communications Amplifiers amplifier.ti.com Computers and Peripherals www.ti.com/computers Data Converters dataconverter.ti.com Consumer Electronics www.ti.com/consumer-apps DLP® Products www.dlp.com Energy and Lighting www.ti.com/energy DSP dsp.ti.com Industrial www.ti.com/industrial Clocks and Timers www.ti.com/clocks Medical www.ti.com/medical Interface interface.ti.com Security www.ti.com/security Logic logic.ti.com Space, Avionics and Defense www.ti.com/space-avionics-defense Power Mgmt power.ti.com Transportation and Automotive www.ti.com/automotive Microcontrollers microcontroller.ti.com Video and Imaging RFID www.ti-rfid.com OMAP Mobile Processors www.ti.com/omap Wireless Connctivity www.ti.com/wirelessconnectivity TI E2E Community Home Page www.ti.com/video e2e.ti.com Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright © 2011, Texas Instruments Incorporated