bq78PL114 www.ti.com................................................................................................................................................................................................. SLUS850 - AUGUST 2008 PowerLANTM Master Gateway Battery Management Controller With PowerPump Cell Balancing FEATURES APPLICATIONS * Designed for Managing up to 10 Series Cell Battery Systems * SmartSafety Features: - Prevention: Optimal Cell Management - Diagnosis: Improved Sensing of Cell Problems - Fail Safe: Detection of Event Precursors * Rate-of-Change Detection of All Important Cell Characteristics: - Voltage - Impedance - Cell Temperature * PowerPump Precision Cell Balancing Transfers Charge Efficiently From Cell to Cell During All Operating Conditions, Resulting in Longer Run Time and Cell Life * High-Resolution 18-Bit Integrating Delta-Sigma Coulomb Counter for Precise Charge-Flow Measurements and Gas Gauging * Multiple Independent - ADCs: One-per-Cell Voltage, Plus Separate Temperature, Current, and Safety * Simultaneous, Synchronous Measurement of Pack Current and Individual Cell Voltages * Very Low Power Consumption: < 250 A Active, < 150 A Standby, < 40 A Ship, and < 1 A Undervoltage Shutdown * Accurate, Advanced Temperature Monitoring of Cells and MOSFETs With up to Six Sensors * Fail-Safe Operation of Pack Protection Circuits: Up to Three Power MOSFETs and One Secondary Safety Output (Fuse) * Fully Programmable Voltage, Current, Balance, and Temperature-Protection Features * External Inputs for Auxiliary MOSFET Control * Smart Battery System 1.1 Compliant via SMBus or SPI Interface With SHA-1 Authentication Option * 23 * * Portable Medical Instruments and Test Equipment Mobility Devices (E-Bike) Uninterruptible Power Supplies and Hand-Held Tools DESCRIPTION The bq78PL114 master gateway battery controller is part of a complete Li-Ion control, monitoring, and safety solution designed for large series cell strings. The bq78PL114, along with PowerLAN cell monitors, provides complete battery system control, communications, and safety functions for a structure of four to 10 series cells. This PowerLAN system provides simultaneous, synchronized voltage and temperature measurements using one-ADC-per-cell technology. Voltage measurements are also synchronized with pack current measurements, eliminating system-induced noise from measurements. This allows the precise, continuous, real-time calculation of cell impedance under all operating conditions, even during widely fluctuating load conditions. PowerPump technology transfers charge between cells to balance their voltage and capacity. Balancing is possible during all battery modes: charge, discharge, and rest. Highly efficient charge-transfer circuitry nearly eliminates energy loss while providing true real-time balance between cells, resulting in longer run-time and improved cycle life. Temperature is sensed by up to six external sensors. This permits accurate temperature monitoring of each cell individually. Firmware is then able to compensate for the temperature-induced effects on capacity, impedance, and OCV on a cell-by-cell basis, resulting in superior charge/ discharge and balancing control. External MOSFET control inputs provide userdefinable direct hardware control over MOSFET states. Smart control prevents excessive current through MOSFET body diodes. Auxiliary inputs can be used for enhanced safety and control in large multicell arrays. 1 2 3 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. PowerLAN is a trademark of Texas Instruments. Battery Wizard is a trademark of Lenmar Enterprises, Inc. PRODUCT PREVIEW information concerns products in the formative or design phase of development. Characteristic data and other specifications are design goals. Texas Instruments reserves the right to change or discontinue these products without notice. Copyright (c) 2008, Texas Instruments Incorporated PRODUCT PREVIEW 1 bq78PL114 SLUS850 - AUGUST 2008................................................................................................................................................................................................. www.ti.com These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. DESCRIPTION (CONTINUED) The bq78PL114 is completely user-configurable, with parametric tables in flash memory to suit a variety of cell chemistries, operating conditions, safety controls, and data reporting needs. It is easily configured using the supplied Battery WizardTM graphical user interface. The device is fully programmed and requires no algorithm or firmware development. P-LAN PRE Voltage PUMP3 Balance Temp PRODUCT PREVIEW XT3 V2 Voltage PUMP2 XT2 Balance Temp V1 Voltage PUMP1 Balance Temp XT1 FLASH V3 CHG First-Level Safety and FET Control DSG EFCID EFCIC SPROT RISC CPU SRAM Balance Temp CELL 4 XT4 CELL 3 PUMP4 CELL 2 Voltage Second-Level Safety CSBAT Coulomb Counter CCBAT CSPACK Current A/D CELL 1 V4 PowerLAN Communication Link Reset Logic RSTN GPIO Internal Oscillator SMBus CCPACK 6 LED1-5, LEDEN SMBCLK SMBDAT SPI-DI VLDO1 Watchdog 2.5 V LDO Core / CPU Measure Internal Temperature SPI SPI-DO SPI-CLK SELECT I/O Safety B0320-02 Figure 1. bq78PL114 Internal Block Diagram 2 Submit Documentation Feedback Copyright (c) 2008, Texas Instruments Incorporated Product Folder Link(s): bq78PL114 bq78PL114 www.ti.com................................................................................................................................................................................................. SLUS850 - AUGUST 2008 Pack Positive SMBus Pack Negative - + Pack Protection Circuits and Fuse Example 8-cell configuration shown bq76PL102 Cell Monitor With PowerPump Balancing bq76PL102 Cell Monitor With PowerPump Balancing PRODUCT PREVIEW PowerLAN Communication Link RSENSE PowerLAN Master Gateway Battery Controller bq78PL114 B0332-01 Figure 2. Example PowerLAN Multicell System Implementation ORDERING INFORMATION (1) Product Cell Configuration (2) Communications bq78PL114 3 to 8 series cells SMBus bq78PL114 bq78PL114 (1) (2) (3) 3 to 10 series cells 3 to 12 series cells SMBus Package QFN-48, 7-mm x 7-mm Package Designator RGZ Temperature Range -40C to 85C Ordering Number Quantity, Transport Media bq78PL114RGZT-8S 250, tape and reel bq78PL114RGZR-8S 2500, tape and reel bq78PL114RGZT-10S (3) 250, tape and reel bq78PL114RGZR-10S (3) 2500, tape and reel bq78PL114RGZT-12S (3) 250, tape and reel bq78PL114RGZR-12S (3) 2500, tape and reel SMBus/SPI Authentication options are also available; contact TI for additional information. For configurations consisting of more than four series cells, additional bq76PL102 parts must be used. Some historical data storage limits exist for the -10S and -12S versions. Submit Documentation Feedback Copyright (c) 2008, Texas Instruments Incorporated Product Folder Link(s): bq78PL114 3 bq78PL114 SLUS850 - AUGUST 2008................................................................................................................................................................................................. www.ti.com AVAILABLE OPTIONS V1 XT1 XT2 V2 VLDO2 V3 XT3 XT4 V4 SMBDAT SMBCLK 46 45 44 43 42 41 40 39 38 37 DSG 47 1 VSS CHG 48 bq78PL114 RGZ Package (Top View) 36 LED5 2 35 LED4 PRE 3 34 LED3 EFCIC 4 33 LED2 EFCID 5 32 LED1 CCBAT 6 31 LEDEN Thermal Pad 24 RSTN P-LAN 25 23 12 P4N OSCO 22 SPI-CLK P4S 26 21 11 P3N OSCI 20 SPI-DI P3S 27 19 10 SDI3 CSPACK 18 SPI-DO SDO2 28 17 9 P2N CSBAT 16 SELECT P2S 29 15 8 P1N VLDO1 14 SPROT SDI1 30 13 7 SDO0 PRODUCT PREVIEW CCPACK P0023-16 Figure 3. bq78PL114 Pinout TERMINAL FUNCTIONS NAME NO. TYPE (1) DESCRIPTION CCBAT 6 IA Coulomb counter input (sense resistor), connect to battery negative CCPACK 7 IA Coulomb counter input (sense resistor), connect to pack negative CHG 1 O Charge MOSFET control (active-high, enables current flow) CSBAT 9 IA Current sense input (safety), connect to battery negative CSPACK 10 IA Current sense input (safety), connect to pack negative DSG 2 O Discharge MOSFET control (active-high, low opens MOSFET) EFCIC 4 I External charge MOSFET control input External discharge MOSFET control input EFCID 5 I LED1 32 IO LED1 - active-low LED2 33 IO LED2 - active-low LED3 34 IO LED3 - active-low LED4 35 IO LED4 - active-low LED5 36 IO LED5 - active-low LEDEN 31 IO LEDEN - common-anode drive (active-high) OSCI 11 I External oscillator input (optional) OSCO 12 O External oscillator output (optional) (1) 4 I - input, IA - analog input, O - output, OA - analog output, OD - open-drain output, P - power Submit Documentation Feedback Copyright (c) 2008, Texas Instruments Incorporated Product Folder Link(s): bq78PL114 bq78PL114 www.ti.com................................................................................................................................................................................................. SLUS850 - AUGUST 2008 TERMINAL FUNCTIONS (continued) NO. TYPE (1) P1N 15 O Charge-balance gate drive, cell 1 north P2S 16 O Charge-balance gate drive, cell 2 south P2N 17 O Charge-balance gate drive, cell 2 north P3N 21 O Charge-balance gate drive, cell 3 north P3S 20 O Charge-balance gate drive, cell 3 south P4N 23 O Charge-balance gate drive, cell 4 north P4S 22 O Charge-balance gate drive, cell 4 south P-LAN 24 IO PowerLAN I/O to external bq76PL10x nodes PRE 3 O Pre-Charge MOSFET control (active-high.) RSTN 25 I Device reset, active-low SDI1 14 I Connect to SDO0 via a capacitor SDI3 19 I Internal PowerLAN connection - connect to SDO2 SDO0 13 O Requires 100-k pullup resistor to VLDO1 SDO2 18 O Internal PowerLAN connection - connect to SDI3 SELECT 29 O Auxiliary SPI control output SMBCLK 37 IO SMBus clock signal SMBDAT 38 IO SMBus data signal SPI-CLK 26 IO SPI port clock (2) SPI-DI 27 I SPI master-out-slave-in (2) SPI-DO 28 O SPI master-in-slave-out (2) SPROT 30 O Secondary protection output, active-high (FUSE) V1 47 IA Cell-1 positive input V2 44 IA Cell-2 positive input V3 42 IA Cell-3 positive input V4 39 IA Cell-4 positive input VLDO1 8 P Internal LDO-1 output, bypass with capacitor VLDO2 43 P Internal LDO-2 output, bypass with capacitor VSS 48 IA Cell-1 negative input XT1 46 IA External temperature-sensor-1 input XT2 45 IA External temperature-sensor-2 input XT3 41 IA External temperature-sensor-3 input XT4 40 IA External temperature-sensor-4 input - - P Thermal pad. Connect to VSS (2) DESCRIPTION (2) PRODUCT PREVIEW NAME SPI functionality requires a firmware option, consult the factory for additional information. Submit Documentation Feedback Copyright (c) 2008, Texas Instruments Incorporated Product Folder Link(s): bq78PL114 5 bq78PL114 SLUS850 - AUGUST 2008................................................................................................................................................................................................. www.ti.com ABSOLUTE MAXIMUM RATINGS (1) over operating free-air temperature range (unless otherwise noted) PRODUCT PREVIEW RANGE UNITS TA Operating free-air temperature (ambient) -40 to 85 C Tstg Storage temperature -65 to 150 C V4-V3 Maximum cell voltage -0.5 to 5.0 V V3-V2 Maximum cell voltage -0.5 to 5.0 V V2-V1 Maximum cell voltage -0.5 to 5.0 V V1-VSS Maximum cell voltage -0.5 to 5.0 V Voltage on LED1-LED5, CCBAT, CCPACK, CSBAT, CSPACK, XT1, XT2, OSCI, OSCO, SDIx, SDOx, SPROT, P-LAN Maximum voltage on any I/O pin (VSS - 0.5) to (VLDO1 + 0.5) V Voltage on XT3, XT4, LEDEN Maximum voltage range (V2 - 0.5) to (VLDO2 + 0.5) V EFCIC, EFCID With respect to VSS -0.5 to 5.5 V Voltage on SMBCLK, SMBDAT With respect to VSS -0.5 to 6 V Voltage on PRE, CHG, DSG With respect to VSS -0.5 to (VLDO1 + 0.5) V Current through PRE, CHG, DSG, LED1-LED5, P-LAN Maximum current source/sink 20 mA VLDO1 maximum current Maximum current draw from VLDO 20 mA ESD tolerance JEDEC, JESD22-A114 human-body model, R = 1500 , C = 100 pF 2 kV Lead temperature, soldering Total time < 3 seconds 300 C (1) 6 Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. Submit Documentation Feedback Copyright (c) 2008, Texas Instruments Incorporated Product Folder Link(s): bq78PL114 bq78PL114 www.ti.com................................................................................................................................................................................................. SLUS850 - AUGUST 2008 ELECTRICAL CHARACTERISTICS TA = -40C to 85C (unless otherwise noted) DC Characteristics PARAMETER VCELL (1) TEST CONDITIONS MIN TYP MAX Operating range Cells balanced IDD Operating-mode current Measure / report state 250 A ISTBY Standby-mode current SMBCLK = SMBDAT = L 100 A 30 A ISHIP 2.3 Ship-mode current Extreme cell under voltage shutdown current All cells < 2.7 V and any cell < ECUV set point VOL General I/O pins IOL < 4 mA VOH (3) General I/O pins IOH < -4 mA VIL General I/O pins VIH General I/O pins IECUV (2) 0 V 1 A 0.5 V VLDO1 - 0.1 V 0.25 VLDO1 0.75 VLDO1 V V Device remains operational to 1.85 V with reduced accuracy and performancce. All cells at 2.3 V at 25C. Does not apply to SMBus pins. PRODUCT PREVIEW (1) (2) (3) 4.5 UNIT Voltage-Measurement Characteristics over operating free-air temperature range (unless otherwise noted) PARAMETER TEST CONDITIONS MIN Measurement range TYP 2.5 MAX 4.5 UNIT V Resolution <1 mV Accuracy 3 mV Current-Sense Characteristics over operating free-air temperature range (unless otherwise noted) PARAMETER TEST CONDITIONS Measurement range (1) MIN TYP -0.2 0.2 Input offset Resolution UNIT V 50 V 18 V 18 V 0.1% of reading Accuracy (2) (1) (2) MAX Default range. Corresponds to 40 A using a 5-m sense resistor. SBData limits the reported current range to 32 A. After calibration. Accuracy is dependent on system calibration and temperature coefficient of sense resistor. Coulomb-Counter Characteristics (1) (2) over operating free-air temperature range (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP Intergral nonlinearity 0.008% Snap-to-zero (deadband) 100 (3) (1) (2) (3) MAX UNIT V Shares common input with Current Sense section After calibration. Accuracy is dependent on system calibration and temperature coefficient of sense resistor. Corresponds to 20 mA using 50-m sense resistor Submit Documentation Feedback Copyright (c) 2008, Texas Instruments Incorporated Product Folder Link(s): bq78PL114 7 bq78PL114 SLUS850 - AUGUST 2008................................................................................................................................................................................................. www.ti.com Current Sense (Safety) Characteristics (1) over operating free-air temperature range (unless otherwise noted) PARAMETER TEST CONDITIONS MIN Measurement range Short-circuit detection Resolution (1) TYP -0.325 MAX UNIT 0.325 V 10 Overcurrent detection, charge and discharge mV 1.25 Post calibration: Dependent on system calibration and temperature coefficient of sense resistor. Uncertainty 1.5 LSB. Internal Temperature Sensor Characteristics (1) over operating free-air temperature range (unless otherwise noted) PARAMETER TEST CONDITIONS MIN Measurement range Resolution Accuracy (1) TYP -30 (1) -30 to 85 MAX 85 UNIT C 0.1 C 1 C After calibration. External Temperature Sensor(s) Typical Characteristics (1) PRODUCT PREVIEW over operating free-air temperature range (unless otherwise noted) PARAMETER TEST CONDITIONS MIN Measurement range (2) TYP -40 90 Resolution 0.2 Accuracy (3) (1) (2) (3) MAX 25 1 0 to 85 2 UNIT C C C Typical for dual diode (MMBD4148 or equivalent) external sensor using recommended circuit. Range of diode sensors may exceed operational limits of IC and battery cells. Typical behavior after calibration, final result dependent on specific component characteristics. SMBus Characteristics (1) over operating free-air temperature range (unless otherwise noted) PARAMETER VIL Input low voltage VIH Input high voltage VOL (2) Output low voltage CI Capacitance, each I/O pin fSCL SCLK nominal clock frequency RPU (3) Pullup resistors for SCLK, SDATA (1) (2) (3) 8 TEST CONDITIONS 350-A sink current MIN TYP MAX UNIT 0 0.8 V 2.1 5.5 V 0 0.4 V 10 pF TA = 25C 100 kHz VBUS 5 V nominal 13.3 45.3 VBUS 3 V nominal 2.4 6.8 k SMBus timing and signals meet the SMBus 2.0 specification requirements under normal operating conditions. All signals are measured with respect to PACK-negative. Parameter not tested in production. Pullups are typically implemented external to battery pack, and are selected to meet SMBus requirements. Submit Documentation Feedback Copyright (c) 2008, Texas Instruments Incorporated Product Folder Link(s): bq78PL114 bq78PL114 www.ti.com................................................................................................................................................................................................. SLUS850 - AUGUST 2008 RPRE + PACK+ PRE CHG DSG Level-Shift Circuits SDI1 SDO2 SDO0 V1 VLDO1 RSTN P-LAN PRODUCT PREVIEW Cell Balancing Circuits CELL 6 V2 bq76PL102 SDI3 CELL 5 SPROT bq78PL114 PowerLAN Gateway Battery Management Controller EFCIC VLDO2 EFCID SPI-CLK SPI-DO SPI-DI V1 SELECT CELL 1 SPI V2 SMBus CELL 2 V3 6 GPIO0-5 ESD Protection CELL 3 Cell Balancing Circuits CELL 4 Aux FET Control V4 SMBCLK Temperature Sensor (typ.) CCPACK CCBAT CSBAT TAB VSS CRFI CSPACK SMBDAT XT1-4 One of 4 external sensors shown - Typical six-cell configuration shown. Additional cells added via PowerLAN connection. Some components omitted for clarity. PACK- RSENSE S0342-02 Figure 4. bq78PL114 Simplified Example Circuit Diagram Submit Documentation Feedback Copyright (c) 2008, Texas Instruments Incorporated Product Folder Link(s): bq78PL114 9 bq78PL114 SLUS850 - AUGUST 2008................................................................................................................................................................................................. www.ti.com FEATURE SET Primary (First-Level) Safety Features The bq78PL114 implements a breadth of system protection features which are easily configured by the customer. First-level protections work by controlling the MOSFET switches. These include: * Battery cell over/undervoltage protection * Pack over/undervoltage protection * Charge and discharge overcurrent protection * Short-circuit protection * External MOSFET control inputs (EFCIx) with programmable polarity * Up to four external temperature inputs for accurate cell and MOSFET monitoring * Watchdog timer protection * Brownout detection and protection against extreme pack undervoltage Secondary (Second-Level) Safety Features PRODUCT PREVIEW The bq78PL114 can detect more serious system faults and activate the SPROT pin, which can be used to open an in-line chemical fuse to permanently disable the pack. Secondary optional features include * Fully independent of first-level protections * SmartSafety algorithms for early detection of potential faults - Temperature abnormalities (variances, extremes, rate of change, etc.) - Disconnected cell voltage inputs - Cell imbalance exceeds safety limits - Impedance rise due to cell or weld strap fault * MOSFET failure or loss of MOSFET control * Safety overvoltage, pack and cell * Safety overtemperature, limits for both charge and discharge * Safety overcurrent, charge and discharge * Failed current measurement, voltage measurement, or temperature measurement Charge Control Features * Meets SMBus 2.0 and Smart Battery System (SBS) Specification 1.1 requirements * Active cell balancing using patented PowerPump technology, which eliminates unrecoverable capacity loss due to normal cell imbalance * Balancing-current monitoring to detect cell problems * Simultaneous, synchronous measurement of all cell voltages in a pack * Simultaneous, synchronous measurement of pack current with cell voltages * Reports target charging current and/or voltage to an SBS Smart Charger * Reports the chemical state-of-charge for each cell and pack * Supports precharging and zero-volt charging with separate MOSFET control * Programmable, Chemistry-specific parameters * Fault reporting Gas Gauging * The bq78PL114 accurately reports battery cell and pack state-of-charge (SOC). No full charge/discharge cycle is required for accurate reporting. * State-of-charge is reported via SMBus and optional LED display. * 18-bit integrating delta-sigma ADC coulomb counter, with programmable snap-to-zero value LED Display * The bq78PL114 drives a three- to five-egment LED display in response to a pushbutton (LEDEN) input signal. Each LED pin can sink up to 10 mA. 10 Submit Documentation Feedback Copyright (c) 2008, Texas Instruments Incorporated Product Folder Link(s): bq78PL114 bq78PL114 www.ti.com................................................................................................................................................................................................. SLUS850 - AUGUST 2008 Lifetime Data Logging (Readable via SMBus or SPI) * Recording of faults, events, anomalies, minimum and maximum values * Maximum/minimum temperature * Maximum/minimum pack voltage * Maximum/minimum cell voltages * Maximum charge and discharge currents Power Modes * Normal Mode: The bq78PL114 performs measurements and calculations, makes decisions, and updates internal data approximately once per second. All safety circuitry is fully functional in this mode. * Standby Mode: The bq78PL114 performs as in normal mode, but at a dramatically reduced rate to lower power consumption at times when the host computer is inactive or the battery system is not being used. All safety circuitry remains fully functional in this mode. * Ship Mode: The bq78PL114 disables (opens) all the protection MOSFETs, and continues to monitor temperature and voltage, but at a reduced measurement rate to dramatically lower power consumption. Environmental data is saved in flash as a part of the historical record. Safety circuitry is disabled in this mode. The device does not enter this power state as a part of normal operation; it is intended for use after factory programming and test. Entry occurs only after a unique SMBus or SPI command is issued. Exit occurs when the SMBus or SPI lines return to an active state. * Extreme Cell Undervoltage (ECUV) Shutdown Mode: In this mode, the bq78PL114 draws minimal current and the charge and discharge protection MOSFETs are disabled (opened). The precharge MOSFET remains enabled when a charge voltage is present. Safety circuitry is disabled in this mode. The device does not enter this mode as a part of normal operation; it enters this state during extreme cell undervoltage conditions (ECUV). The ECUV threshold is fully programmable below 2.7V. STATE CURRENT DRAW (Typ) OVERCURRENT PROTECTION ENTRY CONDITION EXIT CONDITION Active < 250 A Fully active Normal operation as determined by firmware Firmware directed to the following operating modes Standby < 150 A Fully active No load current flowing for predetermined time Load activity Ship < 40 A Not active Protected SMBus or SPI command SMBus or SPI becomes active < 1 A Not active (precharge enabled) Enabled when Vcell < ECUV Vcell charge above ECUV recovery threshold (2.7 V/cell typical) Extreme cell undervoltage OPERATION The bq78PL114 battery management controller serves as the master controller for a Li-Ion battery system consisting of up to 10 cells in series. Any number may be connected in parallel; other system or safety issues limit the number of parallel cells. The bq78PL114 provides extraordinarily precise state-of-charge gas gauging along with first and second level pack safety functions. Voltage and current measurements are performed synchronously and simultaneously for all cells in the system, allowing a level of precision not previously possible Submit Documentation Feedback Copyright (c) 2008, Texas Instruments Incorporated Product Folder Link(s): bq78PL114 11 PRODUCT PREVIEW Forensic Data Logging (Readable via SMBus or SPI) * Last known full capacity of each cell * Cycle count and/or cumulative number of ampere-hours delivered by the battery * Battery pack status: being charged, discharged, or at rest * Balancing effort required by each bank of cells to maintain balance * Information for each cell bank for period leading up to failure * Last 10 failures causing first-level safety action * Forensic data up-loadable to host CPU via SMBus or SPI * Forensic data recording of anomalies and events bq78PL114 SLUS850 - AUGUST 2008................................................................................................................................................................................................. www.ti.com in battery management. Temperature is measured by up to four additional external temperature sensors, for a total of five independent measurement points. (Additional cell temperature sensors are available in remote bq76PL102 dual-cell battery monitors.) Coulomb counting is captured continuously by a dedicated 18-bit integrating delta-sigma ADC in the bq78PL114. The CPU in the bq78PL114 is also responsible for system data calculations, black-box forensic data storage, and communicating parameters via the SMBus or SPI interface. PowerLAN Communication Link PowerLAN technology is Texas Instruments' patented serial network and protocol designed specifically for battery management in a multicell system environment. The PowerLAN link is used to initiate and report measurements of cell voltage and temperature, and control cell balancing. The bq78PL114 serves as the master controller of the PowerLAN link and can interface to multiple bq76PL102 dual-cell battery monitors, which measure and balance additional cells. The bq78PL1114 monitors the first three or four cells, and bq76PL102s can be added to monitor more series cells. The PowerLAN link isolates voltages from adjacent bq76PL102 devices to permit high-voltage stack assembly without compromising precision and accuracy. The PowerLAN link is expandable to support up to 10 cells in series. Each bq76PL102 handles voltage and temperature measurements, as well as balancing for two cells. The PowerLAN link provides high ESD tolerance and high immunity to noise generated by nearby digital circuitry or switching currents. Each bq76PL102 has both a PowerLAN input and PowerLAN output: Received data is buffered and retransmitted, permitting high numbers of nodes without loss of signal fidelity. Signals are capacitor-coupled between nodes, providing dc isolation. PRODUCT PREVIEW Safety Unique in the battery-management controller market, the bq78PL114 simultaneously measures voltage and current using independent and highly accurate delta-sigma ADCs. This technique removes virtually all systemic noise from measurements, which are made during all modes of battery operation: charge, discharge, and rest. The bq78PL114 also directs all connected bq76PL102 dual-cell battery monitors to measure each cell voltage simultaneously with the bq78PL114 measurements. Battery impedance and self-discharge characteristics are thus measured with an unprecedented level of accuracy in real time. The bq78PL114 applies this precise information to SmartSafety algorithms to detect certain anomalies and conditions which may be indicative of internal cell faults, before they become serious problems. The bq78PL114 uses its enhanced measurement system to detect system faults including cell under- and overvoltage, cell under- and overtemperature, system overvoltage, and system overcurrent. First-level safety algorithms first attempt to open the MOSFET safety switches. If this fails, second-level safety algorithms ctivate the SPROT output, normally used to open a fuse and provide permanent, hard protection for the systems. External MOSFET control inputs with programmable polarity can also be used to operate the safety MOSFETs under control of user supplied circuitry. The bq78PL114 continuously monitors these inputs. If any MOSFET fails to open when commanded; the 2nd level safety algorithms also activate the SPROT output. All first- and second-level safety algorithms have fully programmable time delays to prevent false triggering. Cell Balancing Patented PowerPump cell balancing drastically increases the useful life of battery packs by eliminating the cycle life fade of multi-cell packs due to cell imbalance. PowerPump efficiently transfers charge from cell to cell, rather than simply bleeding off charging energy as heat as is typically done with resistive-bleed balancing circuits. Balancing is configurable and may be performed during any battery operational modes: charge, discharge, or rest. Compared to resistive bleed balancing, virtually no energy is lost as heat. The actual balance current is externally scalable and can range from 10 mA to 1 A (100 mA typical) depending on component selection and system or cell requirements. A variety of techniques, such as simple terminal voltage, terminal voltage corrected for impedance and temperature effects, or state-of-charge balancing, is easily implemented by the bq78PL114. In some cases, chemistry-specific algorithms are available. By tracking the balancing required by individual cells, overall battery safety is enhanced, often allowing early detection of soft shorts or other cell failures. Balancing is achieved between all cells within the pack as dynamically determined by the bq78PL114. 12 Submit Documentation Feedback Copyright (c) 2008, Texas Instruments Incorporated Product Folder Link(s): bq78PL114 bq78PL114 www.ti.com................................................................................................................................................................................................. SLUS850 - AUGUST 2008 Outputs Charge Control The open-drain outputs CHG and PRE are ordinarily used to drive MOSFET transistors controlling charge to the cell stack. Charge or precharge mode is selected based on the present cell voltage compared to the user-definable cell precharge, undervoltage, and temperature thresholds. When below these limits, the PRE signal is active and the CHG signal is inactive. This turns on the precharge MOSFET and is used to charge a depleted system through a current-limiting series resistor. When all cell voltages are above the limit and the temperature is above the charge temperature minimum, then the CHG output also becomes active and enables the charge MOSFET to turn on, providing a high-current path between charger and battery cells. The CHG and PRE MOSFET control outputs are both disabled (low) when any cell reaches the safety cutoff limit or temperature threshold. During active charging modes (and above cell voltage thresholds), the discharge MOSFET is also enabled to avoid excessive heating of the body diode. Similarly, the charge MOSFET is active during discharge, provided current flow is in the correct direction and no safety violations are present. The CHG and PRE outputs are intended to drive buffer transistors acting as inverting level shifters. The DSG output operates similarly to control-system discharging. It is enabled (high) by default. If a cell voltage falls below a programmable threshold, or excessive current or other safety related fault is sensed, the DSG output is disabled (low) to prevent damage to the cells. All facets of safely charging and discharging the cell stack are controlled by user-definable parameters which provide precise control over MOSFET states. Both system and cell over- and undervoltage limits are provided, as well as programmable hysteresis to prevent oscillation. Temperature and current thresholds are also provided, each with independent timers to prevent nuisance activations. LEDEN LEDEN is a dual-function pin. One function is to provide output current to the LED display array. It also serves as an input that monitors for closure of a state-of-charge indicator (SOCi) push-button switch. LED SOCi Outputs LED1-LED5 are current-sinking outputs designed to drive low-current LEDs. The LEDs can be activated by the LEDEN pin via a pushbutton switch. They can be configured (using SBS parameters) to operate in bar or dot mode and to use three to five LEDs to represent state-of-charge information. Inputs Current Measurement Current is monitored by four separate ADCs. All use the same very low-value sense resistor, typically 10 milliohms in series with the pack negative connection. CCBAT and CCPACK connections to resistor use an R/C filter for noise reduction. (CSBAT and CSPACK are direct connections used for safety.) It is possible to use even lower values for the sense resistor in very high-current designs by external circuitry. Contact Texas Instruments directly for details. either 5 or the sense secondary employing A 14-bit delta-sigma ADC is used to measure current flow accurately in both directions. The measurements are taken simultaneously and synchronously with all the cell voltage measurements, even those cells measured by bq76PL102 dual-cell battery monitors. Coulomb Counting A dedicated coulomb counter is used to measure charge flow with 18 bit precision in both directions by a calibrated, integrating delta-sigma ADC. This allows the bq78PL114 to keep very accurate state-of-charge (SOC) information and battery statistics. A small deadband is applied to further reduce noise effects. The coulomb counter is unique in that it continues to accumulate (integrate) current flow in either direction even as the rest of the internal microcontroller is placed in a very low power state, further lowering power consumption without compromising system accuracy. Submit Documentation Feedback Copyright (c) 2008, Texas Instruments Incorporated Product Folder Link(s): bq78PL114 13 PRODUCT PREVIEW Discharge Control bq78PL114 SLUS850 - AUGUST 2008................................................................................................................................................................................................. www.ti.com Safety Current Two additional ADCs are used to directly monitor for overcurrent or short-circuit current conditions, independently of the internal function. This provides a direct and rapid response to insure pack integrity and safe operation by opening the appropriate MOSFETs. These functions are implemented in hardware, and do not require firmware for functionality. Voltage Measurement Voltage measurement is performed by four independent delta-sigma ADCs which operate simultaneously and are triggered synchronously so that all voltages are read at precisely the same moment. The bq78PL114 coordinates the attached bq76PL102 dual-cell battery monitors so they also perform their cell voltage measurements in sync with the bq78PL114 voltage and current measurements. Voltage measurements are converted with better than 1 mV of resolution, providing superior accuracy. One-ADC-per-cell technology means that voltage is also measured simultaneously with current, permitting accurate, real-time cell impedance calculation during all operating conditions. This technique also provides greatly enhanced noise immunity and filtering of the input signal without signal loss. Temperature Measurement PRODUCT PREVIEW XT1-XT4 are dedicated temperature inputs. Each external sensor consists of a low-cost silicon diode (dual diode in one package is recommended) and capacitor combination. XT1, multiplexed with the LED1 and LED2 inputs, is used to measure cells 1 and 3. XT2, multiplexed with the LED1 and LED2 inputs, is used to measure cells 2 and 4. XT3 is a dedicated IC-temperature sensor, which should be placed near the bq78PL114 IC. XT4 is dedicated to protection-MOSFET temperature and governed by safety rules. The sensor attached to XT4 should be placed near the pack-disconnect MOSFETs. Temperatures for cells 5 and above are measured by external bq76PL102(s), and the temperature data is received by the bq78PL114 over the PowerLAN link for processing. The bq78PL114 can report all of these temperatures individually and as an average. A single internal, integrated silicon sensor is also supplied in the bq78PL114. Note that additional external temperature sensors can be added using bq76PL102 dual-cell battery monitors operating on the PowerLAN link. Each bq76PL102 contains one internal temperature monitor and two additional external temperature-sensor inputs (in addition to the two cell-voltage measurements and cell balancing). EFCIx The external MOSFET control inputs are for user control of MOSFETs based on external circuitry and conditions. The polarity of the input signal is user programmable. Two modes of operation are possible. The first mode is used to implement additional hardware safety inputs, and is used to force the protection MOSFETs to an OFF state. The polarity of the input signals is programmable. The inputs can also be used to control the MOSFETs directly through hardware, with no firmware operation required. COMMUNICATIONS SMBus The bq78PL114 uses the industry-standard Smart Battery System's two-wire System Management Bus (SMBus) communications protocol for all external communication. SMBus version 2.0 is supported by the bq78PL114, and includes clock stretching, bus fault time-out detection, and optional packet error checking (PEC). For additional information, see the www.smbus.org and www.sbs-forum.org Web sites. SPI The bq78PL114 provides a standard serial peripheral interface (SPI) port consisting of SELECT, SPI-DI, SPI-DO, and SPI-CLK signals. This port may be operated as a master or slave SPI port. A typical system configuration uses the bq78PL114 as a SPI slave device so that a host controller could access the various battery data using the industry-standard Smart Battery Data specification for content. Alternatively, the SPI port may be operated as a master to allow the bq78PL114 to write selected system data to another device for use in an autonomous application. Contact Texas Instruments for additional SPI options and details. 14 Submit Documentation Feedback Copyright (c) 2008, Texas Instruments Incorporated Product Folder Link(s): bq78PL114 bq78PL114 www.ti.com................................................................................................................................................................................................. SLUS850 - AUGUST 2008 Smart Battery Data (SBData) The data content and formatting of the bq78PL114 information conforms to the Smart Battery System's (SBS) Smart Battery Data specification, version 1.1. See the SBS/SMBus site at www.sbs-forum.com for further information regarding these specifications. This SBS Data (SBData) specification defines read/write commands for accessing data commonly required in laptop computer applications. The commands are generic enough to be useful in most applications. PRODUCT PREVIEW Because the bq78PL114 provides a wealth of control and battery information beyond the SBData standard, new command codes have been defined by Texas Instruments. In addition, new battery data features, such as state-of-health, use newly defined extended SBData command codes. Standard SMBus protocols are used, although additional data values beyond those defined by the Smart Battery Data specification are employed. (For example, the bq78PL114 typically is used in a multicell battery system and may report individual cell voltages for up to 10 cells. The SBData command set only defines four cell-voltage registers.) Submit Documentation Feedback Copyright (c) 2008, Texas Instruments Incorporated Product Folder Link(s): bq78PL114 15 bq78PL114 SLUS850 - AUGUST 2008................................................................................................................................................................................................. www.ti.com SBS Standard Data Parameter List (Abridged) (1) (2) PRODUCT PREVIEW Command Data Type Descripotion 00 R/W word (unsigned) Manufacturer Access 01 R/W word (unsigned) Remaining Capacity Alarm Level 02 R/W word (unsigned) Remaining Time Alarm Level 03 R/W word (unsigned) Battery Mode 04 R/W word (unsigned) At Rate value used in AtRate calculations 05 Read word (unsigned) At Rate Time to Full 06 Read word (unsigned) At Rate Time to Empty 07 Read word (Boolean) At Rate OK 08 Read word (unsigned) Pack Temperature (maximum of all individual cells) 09 Read word (unsigned) Pack Voltage (sum of individual cell readings) 0A Read word (unsigned) Pack Current 0B Read word (unsigned) Average Pack Current 0C Read word (unsigned) Max Error 0D Read word (unsigned) Relative State of Charge 0E Read word (unsigned) Absolute State of Charge 0F Read word (unsigned) Remaining Pack Capacity 10 Read word (unsigned) Full Charge Capacity 11 Read word (unsigned) Run Time to Empty 12 Read word (unsigned) Average Time to Empty 13 Read word (unsigned) Average Time to Full 14 Read word (unsigned) Charging Current 15 Read word (unsigned) Charging Voltage 16 Read word (unsigned) Battery Status 17 Read word (unsigned) Cycle Count 18 Read word (unsigned) Design Capacity 19 Read word (unsigned) Design Voltage 1A Read word (unsigned) Specification Information 1B Read word (unsigned) Manufacture Date 1C Read word (unsigned) Serial Number 1D-1F Reserved 20 Read block (string) Pack Manufacturer Name (31 characters maximum) 21 Read block (string) Pack Device Name (31 characters maximum) 22 Read block (string) Pack Chemistry 23 Read block (string) Manufacturer Data 24-2E Reserved 2F R/W Block 30-3B Reserved 3C R/W word (unsigned) Optional Manufacturer Function 4 (Vcell 4) 3D R/W word (unsigned) Optional Manufacturer Function 3 (Vcell 3) 3E R/W word (unsigned) Optional Manufacturer Function 2 (Vcell 2) 3F R/W word (unsigned) Optional Manufacturer Function 1 (Vcell 1) 40-45 Unused 46-47 Reserved 48-4F Unused 50-55 Reserved (1) (2) 16 Optional Manufacturer Function 5 Parameters 0x00-0x3F are compatible with the SBDATA specification. By default, the bq78PL114 initially responds to the SBData slave address <0001 011R/W> (0x16, 0x17). Submit Documentation Feedback Copyright (c) 2008, Texas Instruments Incorporated Product Folder Link(s): bq78PL114 bq78PL114 www.ti.com................................................................................................................................................................................................. SLUS850 - AUGUST 2008 Data Type 56-57 Unused 58-5A Reserved 5B-5F Unused 60-62 Reserved 63-6F Unused 70 Reserved 71-FF Unused Descripotion PRODUCT PREVIEW Command Submit Documentation Feedback Copyright (c) 2008, Texas Instruments Incorporated Product Folder Link(s): bq78PL114 17 bq78PL114 SLUS850 - AUGUST 2008................................................................................................................................................................................................. www.ti.com REFERENCE SCHEMATIC (3 Series Cells) PRODUCT PREVIEW 18 Submit Documentation Feedback Copyright (c) 2008, Texas Instruments Incorporated Product Folder Link(s): bq78PL114 bq78PL114 www.ti.com................................................................................................................................................................................................. SLUS850 - AUGUST 2008 PRODUCT PREVIEW REFERENCE SCHEMATIC (8 Series Cells) Submit Documentation Feedback Copyright (c) 2008, Texas Instruments Incorporated Product Folder Link(s): bq78PL114 19 PACKAGE OPTION ADDENDUM www.ti.com 14-Aug-2008 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty BQ78PL114RGZR PREVIEW QFN RGZ 48 2500 TBD Call TI Call TI BQ78PL114RGZT PREVIEW QFN RGZ 48 250 TBD Call TI Call TI Lead/Ball Finish MSL Peak Temp (3) (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. 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