BQ76925PWR

Product Folder Order Now Support & Community Tools & Software Technical Documents BQ76925 SLUSAM9E – JULY 2011 – REVISED APRIL 2020 BQ76925 3-Series to 6-Series Cell Li-Ion and Li-Phosphate Battery Monitor (Analog Front End) 1 Features 3 Description • The BQ76925 host-controlled analog front end (AFE) is part of a complete pack monitoring, balancing, and protection system for 3-, 4-, 5-, or 6-series cell li-ion and li-polymer batteries. The BQ76925 device allows a host controller to monitor individual cell voltages, pack current and temperature easily. The Host may use this information to determine unsafe or faulty operating conditions such as overvoltage, undervoltage, overtemperature, overcurrent, cell imbalance, state of charge, and state of health conditions. 1 • • • • • • • • • • Analog interface for host cell measurement – Cell input MUX, level shifter, and scaler – 1.5-/ 3.0-V low-drift, calibrated reference allows accurate analog-to-digital conversions Analog interface for host current measurement – Variable gain current sense amplifier capable of operation with 1-mΩ sense resistor Switchable thermistor bias output for host temperature measurements Overcurrent comparator with dynamically adjustable threshold – Alerts host to potential overcurrent faults – Wakes up host on load connect Integrated cell balancing FETs – Individual host control – 50 mA per cell balancing current Supports cell sense-line open wire detection Integrated 3.3-V regulator for powering microcontroller or LEDs I2C interface for host communications – Optional packet CRC for robust operation Supply voltage range from 4.2 V to 26.4 V Low power consumption – 40 µA typical in NORMAL mode – 1.5 µA maximum in SLEEP mode 20-pin TSSOP or 24-pin VQFN package Cell input voltages are level-shifted, multiplexed, scaled, and output for measurement by a host ADC. A dedicated pin provides a low-drift calibrated reference voltage to enable accurate measurements. Device Information(1) PART NUMBER • Primary Protection in Li-Ion Battery Packs – Cordless power tools – Light electric vehicles (e-Bike, scooter, for example) – UPS systems – Medical Equipment – Portable Test Equipment BODY SIZE (NOM) BQ76925 TSSOP (20) 4.00 mm × 4.00 mm BQ76925 VQFN (24) 6.50 mm × 4.40 mm (1) For all available packages, see the orderable addendum at the end of the datasheet. Simplified Schematic PACK+ RBAT CV3P3 CBAT BAT VCTL VC6 V3P3 VC5 SCL RIN CIN RIN CIN RIN RIN CIN CIN CREF (Optional) VREF bq76925 VC2 VTB VC1 VCOUT VC0 VIOUT VSS ALERT SENSEN CIN VCC I2C SDA VC4 VC3 RIN RIN 2 Applications PACKAGE ADC Ref MCU RTH CTH RNTC ADC1 (Temp) ADC2 (Voltage) ADC3 (Current) COUT SENSEP GPIO (Alert) GPIO GPIO FET Control Or Fault signaling VSS COUT CIN CSENSE RIN RSENSEN RSENSEP CIN RSENSE PACK- 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. BQ76925 SLUSAM9E – JULY 2011 – REVISED APRIL 2020 www.ti.com Table of Contents 1 2 3 4 5 6 7 Features .................................................................. Applications ........................................................... Description ............................................................. Revision History..................................................... Description (Continued) ........................................ Pin Configuration and Functions ......................... Specifications......................................................... 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 7.10 7.11 7.12 7.13 7.14 7.15 1 1 1 2 3 3 4 Absolute Maximum Ratings ...................................... 4 ESD Ratings ............................................................ 4 Recommended Operating Conditions....................... 5 Thermal Information .................................................. 5 Electrical Characteristics: Supply Current ................ 6 Internal Power Control (Startup and Shutdown) ....... 6 3.3-V Voltage Regulator............................................ 6 Voltage Reference .................................................... 7 Cell Voltage Amplifier................................................ 7 Current Sense Amplifier .......................................... 7 Overcurrent Comparator ......................................... 8 Internal Temperature Measurement ....................... 8 Cell Balancing and Open Cell Detection................. 8 I2C Compatible Interface......................................... 9 Typical Characteristics .......................................... 10 8 Detailed Description ............................................ 11 8.1 8.2 8.3 8.4 8.5 8.6 9 Overview ................................................................. Functional Block Diagram ....................................... Feature Description................................................. Device Functional Modes........................................ Programming........................................................... Register Maps ........................................................ 11 12 12 18 20 22 Application and Implementation ........................ 28 9.1 Application Information............................................ 28 9.2 Typical Application ................................................. 29 10 Power Supply Recommendations ..................... 32 11 Layout................................................................... 32 11.1 Layout Guidelines ................................................. 32 11.2 Layout Example .................................................... 32 12 Device and Documentation Support ................. 34 12.1 12.2 12.3 12.4 12.5 12.6 Documentation Support ....................................... Receiving Notification of Documentation Updates Support Resources ............................................... Trademarks ........................................................... Electrostatic Discharge Caution ............................ Glossary ................................................................ 34 34 34 34 34 34 13 Mechanical, Packaging, and Orderable Information ........................................................... 34 4 Revision History NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Revision D (October 2016) to Revision E Page • Changed the title of the data sheet ....................................................................................................................................... 1 • Changed ZXTP2504DFH to ZXTP25040DFH...................................................................................................................... 28 Changes from Revision C (July 2015) to Revision D Page • Added test condition n = 1 – 5 at 25°C and MAX value for IVCn parameter ........................................................................... 6 • Added Receiving Notification of Documentation Updates section ....................................................................................... 34 Changes from Revision B (December 2011) to Revision C Page • Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information section. ................................................................................................ 1 • Moved content to new sections and added hyperlinks to corresponding sections, figures, tables and documents. ............. 1 • Moved RBAT, CBAT, RIN, CIN, RSENSEN, RSENSEP, CSENSE, RVCTL, CV3P3, CREF, and COUT table rows to Design Requirements .. 5 Changes from Revision A (July 2011) to Revision B • 2 Page Added 24-pin QFN (RGE) Package to Production Data ........................................................................................................ 3 Submit Documentation Feedback Copyright © 2011–2020, Texas Instruments Incorporated Product Folder Links: BQ76925 BQ76925 www.ti.com SLUSAM9E – JULY 2011 – REVISED APRIL 2020 5 Description (Continued) The voltage across an external-sense resistor is amplified and output to a host ADC for both charge and discharge current measurements. Two gain settings enable operation with a variety of sense resistor values over a wide range of pack currents. To enable temperature measurements by the host, the AFE provides a separate output pin for biasing an external thermistor network. This output can be switched on and off under host control to minimize power consumption. The BQ76925 device includes a comparator with a dynamically selectable threshold for monitoring current. The comparator result is driven through an open-drain output to alert the host when the threshold is exceeded. This feature can be used to wake up the host on connection of the load, or to alert the host to a potential fault condition. The BQ76925 device integrates cell balancing FETs that are fully controlled by the host. The balancing current is set by external resistors up to a maximum value of 50 mA. These same FETs may be utilized in conjunction with cell voltage measurements to detect an open wire on a cell sense-line. The host communicates with the AFE through an I2C interface. A packet CRC may optionally be used to ensure robust operation. The device may be put into a low-current sleep mode through the I2C interface and awakened by pulling up the ALERT pin. 6 Pin Configuration and Functions PW Package 20-Pin TTSOP Top View BAT VCTL NC NC V3P3 SCL 23 22 21 20 19 V3P3 24 RGE Package 24-Pin QFN With Thermal Pad Top View VCTL 1 20 BAT 2 19 SCL VC6 3 18 SDA VC5 4 17 VREF VC4 5 16 VTB VC6 1 18 SDA VC3 6 15 VCOUT VC5 2 17 VREF VC2 7 14 VIOUT VC4 3 16 VTB VC1 8 13 ALERT VC0 9 12 SENSEP VC3 4 15 VCOUT VSS 10 11 SENSEN VC2 5 14 VIOUT VC1 6 13 ALERT 7 8 9 10 11 12 VC0 VSS NC NC SENSEN SENSEP Thermal Pad Pin Functions NAME PIN NO. TYPE DESCRIPTION TSSOP VQFN VCTL 1 23 Output 3.3-V Regulator control voltage (1) ALERT 13 13 Output Overcurrent alert (open drain) BAT 2 24 Power Supply voltage, tied to most positive cell NC — 9, 10, 21, 22 — SCL 19 19 Input I2C Clock (open drain) SDA 18 18 Input / Output I2C Data (open drain) SENSEN 11 11 Input (1) No Connection (leave open) Negative current sense When a bypass FET is used to supply the regulated 3.3-V load current, VCTL automatically adjusts to keep V3P3 = 3.3 V. If VCTL is tied to BAT, the load current is supplied through V3P3. Submit Documentation Feedback Copyright © 2011–2020, Texas Instruments Incorporated Product Folder Links: BQ76925 3 BQ76925 SLUSAM9E – JULY 2011 – REVISED APRIL 2020 www.ti.com Pin Functions (continued) NAME PIN NO. TYPE DESCRIPTION TSSOP VQFN SENSEP 12 12 Input V3P3 20 20 Output VC6 3 1 Input Sense voltage for most positive cell VC5 4 2 Input Sense voltage for second most positive cell VC4 5 3 Input Sense voltage for third most positive cell VC3 6 4 Input Sense voltage for fourth most positive cell VC2 7 5 Input Sense voltage for fifth most positive cell VC1 8 6 Input Sense voltage for least positive cell VC0 9 7 Input Sense voltage for negative end of cell stack VCOUT 15 15 Output Cell measurement voltage VIOUT 14 14 Output Current measurement voltage VREF 17 17 Output Reference voltage for ADC VSS 10 8 Power Ground VTB 16 16 Output Bias voltage for thermistor network Positive current sense 3.3-V Regulator 7 Specifications 7.1 Absolute Maximum Ratings over operating free-air temperature range (unless otherwise noted) VBAT VI Supply voltage Input voltage (1) MIN MAX UNIT BAT –0.3 36 V Cell input differential, VCn to VCn+1, n = 0 to 5 –0.3 9 Cell input, VCn, n = 1 to 6 –0.3 (6 × n) BAT to VC6 differential –10 10 –3 3 VC0 (2) SENSEP, SENSEN –3 3 SCL, SDA –0.3 6 VCOUT, VIOUT, VREF –0.3 3.6 VTB, V3P3 –0.3 7 ALERT –0.3 30 VCTL –0.3 36 V VO Output voltage ICB Cell balancing current 70 mA IIN Cell input current –25 70 mA Tstg Storage temperature –65 150 °C (1) (2) V Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. Negative voltage swings on VC0 in the absolute maximum range can cause unwanted circuit behavior and should be avoided. 7.2 ESD Ratings VALUE V(ESD) (1) (2) 4 Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1) ±2000 Charged-device model (CDM), per JEDEC specification JESD22-C101 (2) ±500 UNIT V JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process. Submit Documentation Feedback Copyright © 2011–2020, Texas Instruments Incorporated Product Folder Links: BQ76925 BQ76925 www.ti.com SLUSAM9E – JULY 2011 – REVISED APRIL 2020 7.3 Recommended Operating Conditions (1) MIN Supply voltage BAT 4.2 Cell input differential, VCn to VCn+1, n = 0 to 5 1.4 NOM Cell input, VCn, n = 1 to 6 BAT to VC6 differential VI SCL, SDA Output voltage 4.4 V V 8 V V –125 375 mV 0 5.5 V 5.5 V 0 26.4 V 0 V3P3 + 0.2 V (2) V3P3 Backfeeding ALERT Wakeup function VCOUT, VIOUT VO V 0 SENSEP VREF UNIT 26.4 4.4 × n –8 VC0, SENSEN Input voltage MAX REFSEL = 0 1.5 REFSEL = 1 3 VTB V V 5.5 V3P3 Regulating 3.3 VCTL ALERT Alert function V V 0.8 26.4 V 0 5.5 V ICB Cell balancing current 0 50 mA TA Operating free-air temperature –25 85 °C TFUNC Functional free-air temperature –40 100 °C (1) (2) All voltages are relative to VSS, except “Cell input differential.” Internal 3.3-V regulator may be overridden (that is, backfed) by applying an external voltage larger than the regulator voltage. 7.4 Thermal Information BQ76925 THERMAL METRIC (1) PW (TSSOP) RGE (VQFN) 20 PINS 24 PINS UNIT RθJA Junction-to-ambient thermal resistance 97.5 36 °C/W RθJC (top) Junction-to-case (top) thermal resistance 31.7 38.6 °C/W RθJB Junction-to-board thermal resistance 48.4 14 °C/W ψJT Junction-to-top characterization parameter 1.5 0.6 °C/W ψJB Junction-to-board characterization parameter 47.9 14 °C/W RθJC (bot) Junction-to-case (bottom) thermal resistance n/a 4.6 °C/W (1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report. Submit Documentation Feedback Copyright © 2011–2020, Texas Instruments Incorporated Product Folder Links: BQ76925 5 BQ76925 SLUSAM9E – JULY 2011 – REVISED APRIL 2020 www.ti.com 7.5 Electrical Characteristics: Supply Current BAT = 4.2 to 26.4 V, VCn = 1.4 to 4.4, TA = –25°C to +85°C Typical values stated where TA = 25°C and BAT= 21.6 V (unless otherwise noted) PARAMETER TEST CONDITION MIN TYP MAX UNIT Normal mode supply current All device functions enabled All pins unloaded SDA and SCL high 40 48 µA Standby mode 1 supply current V3P3 and overcurrent monitor enabled All pins unloaded All other device functions disabled SDA and SCL high 14 17 µA IDD3 Standby mode 2 supply current V3P3 enabled All pins unloaded All device functions disabled SDA and SCL high 12 14 V IDD4 Sleep mode supply current V3P3 disabled All pins unloaded All device functions disabled SDA and SCL low 1 1.5 µA IVCn Input current for selected cell All cell voltages equal Cell balancing disabled Open cell detection disabled during cell voltage monitoring Cell to cell input current difference All cell voltages equal Cell balancing disabled Open cell detection disabled IDD1 IDD2 ∆IVCn n=6 2.4 2.7 n=1–5 < 0.5 n = 1 – 5 at 25°C < 0.3 µA < 0.2 µA UNIT 7.6 Internal Power Control (Startup and Shutdown) PARAMETER TEST CONDITION MIN TYP MAX (1) 4.3 4.5 4.7 V Initial BAT > 1.4 VBAT rising (1) 6.5 7 7.5 V 3.6 V Initial BAT < 1.4 VBAT rising VPOR Power on reset voltage Measured at BAT pin VSHUT Shutdown voltage (2) Measured at BAT pin, BAT falling tPOR Time delay after POR before I2C comms allowed CV3P3 = 4.7 µF VWAKE Wakeup voltage Measured at ALERT pin tWAKE_PLS Wakeup signal pulse width tWAKE_DLY Time delay after wakeup before I2C comms allowed (1) (2) 1 ms 0.8 2 V 1 5 μs 1 ms CV3P3 = 4.7 µF Initial power up will start with BAT < 1.4 V, however if BAT falls below VSHUT after rising above VPOR, the power on threshold depends on the minimum level reached by BAT after falling below VSHUT. Following POR, the device will operate down to this voltage. 7.7 3.3-V Voltage Regulator PARAMETER VCTL Regulator control voltage VV3P3 Regulator output IREG V3P3 output current ISC TEST CONDITION (1) (2) MIN Measured at VCTL, V3P3 regulating 3.3 Measured at V3P3, IREG = 0 to 4 mA, BAT = 4.2 to 26.4 V 3.2 V3P3 short circuit current limit V3P3 = 0.0 V 10 VTB Thermistor bias voltage Measured at VTB, ITB = 0 ITB Thermistor bias current RTB Thermistor bias internal resistance RDS(ON) for internal FET switch, ITB = 1 mA (1) (2) 6 TYP 3.3 MAX UNIT 26.4 V 3.4 V 4 mA 17 mA VV3P3 V 1 90 130 mA Ω When a bypass FET is used to supply the regulated 3.3 V load current, VCTL automatically adjusts to keep V3P3 = 3.3 V. Note that VCTL,MIN and the FET VGS will determine the minimum BAT voltage at which the bypass FET will operate. If VCTL is tied to BAT, the load current is supplied through V3P3. Submit Documentation Feedback Copyright © 2011–2020, Texas Instruments Incorporated Product Folder Links: BQ76925 BQ76925 www.ti.com SLUSAM9E – JULY 2011 – REVISED APRIL 2020 7.8 Voltage Reference PARAMETER VREF Voltage reference output TEST CONDITION Before gain correction, TA = 25°C After gain correction, TA = 25°C VREF_CAL Reference calibration voltage Measured at VCOUT ∆VREF Voltage reference tolerance TA = 0 – 50°C IREF VREF output current (1) (1) MAX UNIT REF_SEL = 0 1.44 MIN TYP 1.56 V REF_SEL = 1 2.88 3.12 REF_SEL = 0 –0.1% REF_SEL = 1 VCOUT_SEL = 2 1.5 +0.1% –0.1% 3 +0.1% –0.9% 0.5 × VREF +0.9% VCOUT_SEL = 3 –0.5% 0.85 × VREF +0.5% (0.85 × VREF) – (0.5 × VREF) –0.3% 0.35 × VREF +0.3% –40 V V 40 ppm/°C 10 µA Gain correction factor determined at final test and stored in non-volatile storage. Gain correction is applied by Host controller. 7.9 Cell Voltage Amplifier PARAMETER TEST CONDITION MIN TYP MAX REF_SEL = 0 –1.6% 0.3 1.5% REF_SEL = 1 –1.6% 0.6 1.5% GVCOUT Cell voltage amplifier gain Measured from VCn to VCOUT OVCOUT Cell voltage amplifier offset Measured from VCn to VCOUT VCOUT ∆VCOUT Cell voltage amp output range (1) Cell voltage amplifier accuracy VCOUT output current (5) tVCOUT Delay from VCn select to VCOUT (5) –16 VCn = 1.4 V to 4.4 V, After correction, (2) Measured at VCOUT (3) REF_SEL = 1 (4) 15 mV REF_SEL = 0 1.47 1.5 1.53 V REF_SEL = 1 2.94 3 3.06 V Measured at VCOUT, VCn = 0 V IVCOUT (1) (2) (3) (4) Measured at VCOUT, VCn = 5 V UNIT 0 V TA = 25°C –3 3 TA = 0°C to 50°C –5 5 TA = –25°C to +85°C –8 8 Output step of 200 mV, COUT = 0.1 µF mV 10 µA 100 µs For VCn values greater than 5 V, VCOUT clamps at approximately V3P3. Correction factor determined at final test and stored in non-volatile storage. Correction is applied by Host controller. Output referred. Input referred accuracy is calculated as ∆VCOUT / GVCOUT (for example, 3 / 0.6 = 5). Correction factors are calibrated for gain of 0.6. Tolerance at gain of 0.3 is approximately doubled. Contact TI for information on devices calibrated to a gain of 0.3. Max DC load for specified accuracy. 7.10 Current Sense Amplifier PARAMETER TEST CONDITION GVIOUT Current sense amplifier gain Measured from SENSEN, SENSEP to VIOUT VIIN Current sense amp input range Measured from SENSEN, SENSEP to VSS Current sense amp output range Measured at VIOUT Zero current output Measured at VIOUT SENSEP = SENSEN VIOUT ∆VIOUT Current amplifier accuracy IVIOUT VIOUT output current (1) MIN TYP MAX UNIT –125 375 mV REF_SEL = 0 0.25 1.25 V REF_SEL = 1 0.5 2.5 V I_GAIN = 0 4 I_GAIN = 1 8 REF_SEL = 0 1 V REF_SEL = 1 2 V –1% (1) 1% 10 µA Max DC load for specified accuracy Submit Documentation Feedback Copyright © 2011–2020, Texas Instruments Incorporated Product Folder Links: BQ76925 7 BQ76925 SLUSAM9E – JULY 2011 – REVISED APRIL 2020 www.ti.com 7.11 Overcurrent Comparator PARAMETER TEST CONDITION MIN Comparator amplifier gain VITRIP Current comparator trip threshold (2) MAX 5 Measured from SENSEP to comparator input GVCOMP UNIT V 1 25 400 mV VITRIP = 25 mV –6 6 mV VITRIP > 25 mV –10% 10% V 0.4 V ∆VITRIP Current comparator accuracy VOL_ALERT ALERT Output Low Logic VOH_ALERT ALERT Output High Logic IALERT ALERT Pulldown current ALERT = 0.4 V, Output driving low IALERT_LKG ALERT Leakage current ALERT = 5 V, Output Hi-Z tOC Comparator response time (1) (2) (3) TYP Minimum VBAT for comparator operation (1) VBAT_COMP IALERT = 1 mA (3) NA NA NA 1 mA