BQ27220YZFR

Sample & Buy Product Folder Support & Community Tools & Software Technical Documents bq27220 SLUSCB7A – MARCH 2016 – REVISED APRIL 2016 bq27220 Single-Cell CEDV Fuel Gauge 1 Features 3 Description • The Texas Instruments bq27220 battery fuel gauge is a single-cell gauge that requires minimal userconfiguration and system microcontroller firmware development, leading to quick system bring-up. The bq27220 device uses the Compensated End-ofDischarge Voltage (CEDV) algorithm for fuel gauging, and provides information such as remaining battery capacity (mAh), state-of-charge (%), runtime-to-empty (min), battery voltage (mV), temperature (°C), and state-of-health (%). 1 • • • Single-Cell Li-Ion Battery Fuel Gauge – Resides in Pack or on System Board – Supports Embedded or Removable Batteries – Powers Directly from Battery with Integrated LDO – Supports a Low-Value (10-mΩ) External Sense Resistor Ultra-Low Power Consumption in NORMAL (50 µA) and SLEEP (9 µA) Modes Battery Fuel Gauging Based on Compensated End-of-Discharge Voltage (CEDV) Technology – Reports Remaining Capacity and State-ofCharge (SOC) with Smoothing Filter – Adjusts Automatically for Battery Aging, SelfDischarge, Temperature, and Rate Changes – Provides Battery State-of-Health (Aging) Estimation Microcontroller Peripheral Supports: – 400-kHz I2C™ Serial Interface – Configurable SOC Interrupt OR Battery Low Digital Output Warning – Internal Temperature Sensor OR Host-Reported Temperature OR External Thermistor 2 Applications • • • • • • • The bq27220 battery fuel gauge has ultra-low power consumption in NORMAL (50 μA) and SLEEP (9 μA) modes, leading to longer battery runtime. Configurable interrupts help save system power and free up the host from continuous polling. Accurate temperature sensing is supported via an external thermistor. Customers can use preloaded CEDV parameters in ROM or can generate custom chemistry parameters using TI's web-based tool, GAUGEPARCAL. Customgenerated parameters can be either programmed in the device RAM by the host on power up of the system or customers can program the parameters to an onboard One-Time Programmable (OTP) memory. Battery fuel gauging with the bq27220 device requires connections only to PACK+ (P+) and PACK– (P–) for a removable battery pack or embedded battery circuit. The tiny, 9-ball, 1.62 mm × 1.58 mm, 0.5-mm pitch NanoFree™ chip scale package (DSBGA) is ideal for space-constrained applications. Smartphones and Feature Phones Tablets Wearables Building Automation Portable Medical/Industrial Handsets Portable Audio Gaming Device Information(1) PART NUMBER bq27220 PACKAGE YZF (9) BODY SIZE (NOM) 1.62 mm × 1.58 mm (1) For all available packages, see the orderable addendum at the end of the data sheet. Simplified Schematic (System-Side) I 2C Bus SRN SCL Coulomb Counter SDA VSYS SRP CPU Battery Pack GPOUT ADC BAT PACKP BIN T VDD 1.8 V LDO 2.2 µF VSS 1 µF PACKN Li-Ion Cell Protection IC NFET NFET 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. bq27220 SLUSCB7A – MARCH 2016 – REVISED APRIL 2016 www.ti.com Table of Contents 1 2 3 4 5 6 Features .................................................................. Applications ........................................................... Description ............................................................. Revision History..................................................... Pin Configuration and Functions ......................... Specifications......................................................... 6.13 Typical Characteristics ............................................ 8 1 1 1 2 3 4 7 Detailed Description .............................................. 9 7.1 Overview ................................................................... 9 7.2 Functional Block Diagram (System-Side Configuration)............................................................. 9 7.3 Feature Description................................................... 9 7.4 Device Functional Modes........................................ 11 6.1 6.2 6.3 6.4 6.5 6.6 6.7 Absolute Maximum Ratings ...................................... 4 ESD Ratings.............................................................. 4 Recommended Operating Conditions....................... 5 Thermal Information .................................................. 5 Supply Current .......................................................... 5 Digital Input and Output DC Characteristics ............. 5 LDO Regulator, Wake-up, and Auto-Shutdown DC Characteristics ........................................................... 6 6.8 LDO Regulator, Wake-up, and Auto-shutdown AC Characteristics ........................................................... 6 6.9 ADC (Temperature and Cell Measurement) Characteristics ........................................................... 6 6.10 Integrating ADC (Coulomb Counter) Characteristics ................................................................................... 6 6.11 I2C-Compatible Interface Communication Timing Characteristics ........................................................... 7 6.12 SHUTDOWN and WAKE-UP Timing ...................... 8 8 Application and Implementation ........................ 12 8.1 Application Information............................................ 12 8.2 Typical Applications ................................................ 12 9 Power Supply Recommendation ........................ 15 9.1 Power Supply Decoupling ....................................... 15 10 Layout................................................................... 15 10.1 Layout Guidelines ................................................. 15 10.2 Layout Example .................................................... 16 11 Device and Documentation Support ................. 17 11.1 11.2 11.3 11.4 11.5 Documentation Support ........................................ Community Resources.......................................... Trademarks ........................................................... Electrostatic Discharge Caution ............................ Glossary ................................................................ 17 17 17 17 17 12 Mechanical, Packaging, and Orderable Information ........................................................... 17 4 Revision History 2 DATE REVISION NOTES April 2016 A PRODUCT PREVIEW to Production Data Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated Product Folder Links: bq27220 bq27220 www.ti.com SLUSCB7A – MARCH 2016 – REVISED APRIL 2016 5 Pin Configuration and Functions Top View 3 2 1 C B A Bottom View 1 2 3 C B A Pin Functions PIN NAME BAT BIN (1) NUMBER C3 B1 TYPE DESCRIPTION PI, AI (1) LDO regulator input and battery voltage measurement input. Kelvin sense connect to the positive battery terminal (PACKP). Connect a capacitor (1 µF) between BAT and VSS. Place the capacitor close to the gauge. DI Battery insertion detection input. If OpConfig [BI_PU_EN] = 1 (default), a logic low on the pin is detected as battery insertion. For a removable pack, the BIN pin can be connected to VSS through a pulldown resistor on the pack, typically the 10-kΩ thermistor; the system board should use a 1.8-MΩ pullup resistor to VDD to ensure the BIN pin is high when a battery is removed. If the battery is embedded in the system or in the pack, it is recommended to leave [BI_PU_EN] = 1 and use a 10-kΩ pulldown resistor from BIN to VSS. If [BI_PU_EN] = 0, then the host must inform the gauge of battery insertion and removal with the BAT_INSERT and BAT_REMOVE subcommands. A 10-kΩ pulldown resistor should be placed between BIN and VSS, even if this pin is unused. NOTE: The BIN pin must not be shorted directly to VCC or VSS and any pullup resistor on the BIN pin must be connected only to VDD and not an external voltage rail. If an external thermistor is used for temperature input, the thermistor should be connected between this pin and VSS. IO = Digital input-output, AI = Analog input, P = Power connection Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated Product Folder Links: bq27220 3 bq27220 SLUSCB7A – MARCH 2016 – REVISED APRIL 2016 www.ti.com Pin Functions (continued) PIN NAME NUMBER TYPE DESCRIPTION This open-drain output can be configured to indicate BAT_LOW when the OpConfig [BATLOWEN] bit is set. By default [BATLOWEN] is cleared and this pin performs an interrupt function (SOC_INT) by pulsing for specific events, such as a change in state-of-charge. Signal polarity for these functions is controlled by the [GPIOPOL] configuration bit. This pin should not be left floating, even if unused; therefore, a 10-kΩ pullup resistor is recommended. If the device is in SHUTDOWN mode, toggling GPOUT makes the gauge exit SHUTDOWN. It is recommended to connect GPOUT to a GPIO of the host MCU so that in case of any inadvertent shutdown condition, the gauge can be commanded to come out of SHUTDOWN. GPOUT A1 DO SCL A3 DIO SDA A2 DIO SRN C2 AI SRP C1 AI VDD B3 PO 1.8-V regulator output. Decouple with a 2.2-μF ceramic capacitor to VSS. This pin is not intended to provide power for other devices in the system. VSS B2 PI Ground pin Slave I2C serial bus for communication with system (Master). Open-drain pins. Use with external 10-kΩ pullup resistors (typical) for each pin. If the external pullup resistors will be disconnected from these pins during normal operation, recommend using external 1-MΩ pulldown resistors to VSS at each pin to avoid floating inputs. Coulomb counter differential inputs expecting an external 10-mΩ, 1% sense resistor. For systemside configurations, Kelvin sense connect SRP to the positive battery terminal (PACKP) side of the external sense resistor. Kelvin sense connect SRN to the other side of the external sense resistor with the positive connection to the system (VSYS). For pack-side configurations with lowside sensing, connect SRP to PACK– and SRN to Cell–. See the Simplified Schematic. No calibration is required. The fuel gauge is pre-calibrated for a standard 10-mΩ, 1% sense resistor. 6 Specifications 6.1 Absolute Maximum Ratings Over operating free-air temperature range (unless otherwise noted) (1) VBAT VSR MIN MAX UNIT BAT pin input voltage range –0.3 6 V SRP and SRN pins input voltage range –0.3 VBAT + 0.3 V 2 V VDD Differential voltage across SRP and SRN. ABS(SRP – SRN) VDD pin supply voltage range (LDO output) –0.3 2 V VIOD Open-drain IO pins (SDA, SCL) –0.3 6 V VIOPP Push-pull IO pins (BIN) –0.3 VDD + 0.3 V TA Operating free-air temperature range –40 85 °C –65 150 °C Storage temperature, Tstg (1) 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. 6.2 ESD Ratings VALUE V(ESD) (1) (2) 4 Electrostatic discharge Human body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1) ±1500 Charged-device model (CDM), per JEDEC specification JESD22-C101 (2) ±250 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 © 2016, Texas Instruments Incorporated Product Folder Links: bq27220 bq27220 www.ti.com SLUSCB7A – MARCH 2016 – REVISED APRIL 2016 6.3 Recommended Operating Conditions TA = 30°C and VBAT = 3.6 V (unless otherwise noted) MIN CBAT (1) CLDO18 (1) VPU (1) (1) NOM External input capacitor for internal LDO between BAT and VSS Nominal capacitor values specified. Recommend a 5% ceramic X5R-type External output capacitor for internal LDO capacitor located close to the device. between VDD and VSS External pullup voltage for open-drain pins (SDA, SCL, GPOUT) MAX UNIT 0.1 μF 2.2 μF 1.62 3.6 V Specified by design. Not production tested. 6.4 Thermal Information bq27220 THERMAL METRIC (1) YZF (DSBGA) UNIT 9 PINS RθJA Junction-to-ambient thermal resistance 64.1 °C/W RθJCtop Junction-to-case (top) thermal resistance 59.8 °C/W RθJB Junction-to-board thermal resistance 52.7 °C/W ψJT Junction-to-top characterization parameter 0.3 °C/W ψJB Junction-to-board characterization parameter 28.3 °C/W RθJCbot Junction-to-case (bottom) thermal resistance 2.4 °C/W (1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953 6.5 Supply Current TA = 30°C and VBAT = 3.6 V (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT ICC (1) NORMAL mode current ILOAD > Sleep Current (2) 50 μA ISLP (1) SLEEP mode current ILOAD < Sleep Current (2) 9 μA SHUTDOWN mode current Fuel gauge in host commanded SHUTDOWN mode. (LDO regulator output disabled) 0.6 μA ISD (1) (1) (2) Specified by design. Not production tested. Wake Comparator Disabled. 6.6 Digital Input and Output DC Characteristics TA = –40°C to 85°C, typical values at TA = 30°C and VBAT = 3.6 V (unless otherwise noted)(Force Note1) (1) PARAMETER VIH(OD) TEST CONDITIONS Input voltage, high (2) External pullup resistor to VPU (3) MIN TYP MAX UNIT VPU × 0.7 V VIH(PP) Input voltage, high VIL Input voltage, low (2) VOL Output voltage, low (2) 0.6 V IOH Output source current, high (2) 0.5 mA Output sink current, low (2) IOL(OD) CIN Ilkg (1) (2) (3) (1) 1.4 (3) V 0.6 V –3 mA Input capacitance (2) (3) 5 pF Input leakage current (SCL, SDA, BIN, GPOUT) 1 μA Specified by design. Not production tested. Open Drain pins: (SCL, SDA, GPOUT) Push-Pull pin: (BIN) Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated Product Folder Links: bq27220 5 bq27220 SLUSCB7A – MARCH 2016 – REVISED APRIL 2016 www.ti.com 6.7 LDO Regulator, Wake-up, and Auto-Shutdown DC Characteristics TA = –40°C to 85°C, typical values at TA = 30°C and VBAT = 3.6 V (unless otherwise noted)(Force Note1) (1) PARAMETER VBAT BAT pin regulator input VDD Regulator output voltage UVLOIT+ VBAT undervoltage lock-out LDO wake-up rising threshold UVLOIT– VBAT undervoltage lock-out LDO auto-shutdown falling threshold VWU+ (1) GPOUT (input) LDO Wake-up rising edge threshold (2) (1) (2) TEST CONDITIONS MIN TYP 2.45 LDO Wake-up from SHUTDOWN mode MAX 4.5 UNIT V 1.85 V 2 V 1.95 V 1.2 V Specified by design. Not production tested. If the device is commanded to SHUTDOWN via I2C with VBAT > UVLOIT+, a wake-up rising edge trigger is required on GPOUT. 6.8 LDO Regulator, Wake-up, and Auto-shutdown AC Characteristics TA = –40°C to 85°C, typical values at TA = 30°C and VBAT = 3.6 V (unless otherwise noted) PARAMETER tSHDN (1) tSHUP (1) tVDD (1) TEST CONDITIONS SHUTDOWN entry time Time delay from SHUTDOWN command to LDO output disable. SHUTDOWN GPOUT low time Minimum low time of GPOUT (input) in SHUTDOWN before WAKEUP tWUVDD (1) Wake-up VDD output delay tPUCD Power-up communication delay Time delay from rising edge of BAT to the Active state. Includes firmware initialization time. TYP MAX UNIT 250 ms μs 10 Initial VDD output delay Time delay from rising edge of GPOUT (input) to nominal VDD output. (1) MIN 13 ms 8 ms 250 ms Specified by design. Not production tested. 6.9 ADC (Temperature and Cell Measurement) Characteristics TA = –40°C to 85°C; typical values at TA = 30°C and VBAT = 3.6 V (unless otherwise noted) (Force Note1) (1) PARAMETER VIN(BAT) BAT pin voltage measurement range tADC_CONV Conversion time TEST CONDITIONS Voltage divider enabled MIN 2.45 Effective resolution (1) TYP MAX 4.5 UNIT V 125 ms 15 bits Specified by design. Not tested in production. 6.10 Integrating ADC (Coulomb Counter) Characteristics TA = –40°C to 85°C; typical values at TA = 30°C and VBAT = 3.6 V (unless otherwise noted)(Force Note1) (1) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT VBAT V VSRCM Input voltage range of SRN, SRP pins VSRDM Input differential voltage range of VSRP–VSRN tSR_CONV Conversion time Single conversion 1 s Effective Resolution Single conversion 16 bits (1) 6 VSS ± 80 mV Specified by design. Not tested in production. Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated Product Folder Links: bq27220 bq27220 www.ti.com SLUSCB7A – MARCH 2016 – REVISED APRIL 2016 6.11 I2C-Compatible Interface Communication Timing Characteristics TA = –40°C to 85°C; typical values at TA = 30°C and VBAT = 3.6 V (unless otherwise noted) (Force Note1) (1) MIN NOM MAX UNIT Standard Mode (100 kHz) 4 μs 4.7 μs 4 μs 4.7 μs 250 ns td(STA) Start to first falling edge of SCL tw(L) SCL pulse duration (low) tw(H) SCL pulse duration (high) tsu(STA) Setup for repeated start tsu(DAT) Data setup time Host drives SDA th(DAT) Data hold time Host drives SDA 0 ns tsu(STOP) Setup time for stop 4 μs t(BUF) Bus free time between stop and start 66 μs tf SCL or SDA fall time (1) tr SCL or SDA rise time fSCL Clock frequency (2) Includes Command Waiting Time 300 (1) ns 300 ns 100 kHz Fast Mode (400 kHz) td(STA) Start to first falling edge of SCL 600 ns tw(L) SCL pulse duration (low) 1300 ns tw(H) SCL pulse duration (high) 600 ns tsu(STA) Setup for repeated start 600 ns tsu(DAT) Data setup time Host drives SDA 100 ns th(DAT) Data hold time Host drives SDA 0 ns tsu(STOP) Setup time for stop 600 ns t(BUF) Bus free time between stop and start 66 μs tf SCL or SDA fall time (1) tr SCL or SDA rise time fSCL Clock frequency (2) (1) (2) Includes Command Waiting Time 300 (1) ns 300 ns 400 kHz Specified by design. Not production tested. If the clock frequency (fSCL) is > 100 kHz, use 1-byte write commands for proper operation. All other transactions types are supported at 400 kHz. (See I2C Interface and I2C Command Waiting Time.) tSU(STA) tw(H) tf tw(L) tr t(BUF) SCL SDA td(STA) tsu(STOP) tf tr th(DAT) tsu(DAT) REPEATED START STOP START Figure 1. I2C-Compatible Interface Timing Diagram Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated Product Folder Links: bq27220 7 bq27220 SLUSCB7A – MARCH 2016 – REVISED APRIL 2016 www.ti.com 6.12 SHUTDOWN and WAKE-UP Timing tPUCD tSHUP tVDD tSHDN tPUCD tWUVDD BAT VDD I2C Bus SHUTDOWN _ ENABLE SHUTDOWN GPOUT * State Off WAKE-UP Active SHUTDOWN WAKE-UP Active * GPOUT is configured as an input for wake-up signaling. Figure 2. SHUTDOWN and WAKE-UP Timing Diagram 6.13 Typical Characteristics 0.6% 0.45% 0.4% Voltage Accuracy Error Current Accuracy Error 0.5% 0.4% 0.3% 0.2% 0.1% 0 0.35% 0.3% 0.25% 0.2% 0.15% 0.1% 0.05% -0.1% -50 0 50 Temperature (qC) 100 0 -60 -40 -20 0 20 40 Temperature (qC) D001 Figure 3. Current Accuracy Error vs. Temperature 60 80 100 D002 Figure 4. Voltage Accuracy Error vs. Temperature Internal Temperature Accuracy Error 0 -1% -2% -3% -4% -5% -6% -50 0 50 Temperature (qC) 100 D003 Figure 5. Internal Temperature Accuracy Error vs. Temperature 8 Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated Product Folder Links: bq27220 bq27220 www.ti.com SLUSCB7A – MARCH 2016 – REVISED APRIL 2016 7 Detailed Description 7.1 Overview The bq27220 fuel gauge accurately predicts the battery capacity and other operational characteristics of a single Li-based rechargeable cell. It can be interrogated by a system processor to provide cell information such as state-of-charge (SoC). The bq27220 monitors charge and discharge activity by sensing the voltage across a small value resistor (10 mΩ typical) between the SRP and SRN pins and in series with the battery. By integrating charge passing through the battery, the battery’s SOC is adjusted during battery charge or discharge. The fuel gauging is derived from the Compensated End of Discharge Voltage (CEDV) method, which uses a mathematical model to correlate remaining state of charge (RSOC) and voltage near to the end of discharge state. This requires a full discharge cycle for a single point FCC update. The implementation models cell voltage (OCV) as a function of battery state of charge (SOC), temperature, and current. The impedance is also a function of SOC and temperature, all of which can be satisfied by using seven parameters: EMF, C0, R0, T0, R1, TC, C1. NOTE The following formatting conventions are used in this document: Commands: italics with parentheses() and no breaking spaces, for example, Control(). Data Flash: italics, bold, and breaking spaces, for example, Design Capacity. Register bits and flags: italics with brackets [ ], for example, [TDA] Data flash bits: italics, bold, and brackets [ ], for example, [LED1] Modes and states: ALL CAPITALS, for example, UNSEALED mode. 7.2 Functional Block Diagram (System-Side Configuration) I 2C Bus SRN SCL Coulomb Counter SDA VSYS SRP CPU Battery Pack GPOUT ADC BAT PACKP BIN T VDD 1.8 V LDO 2.2 µF VSS 1 µF PACKN Li-Ion Cell Protection IC NFET NFET 7.3 Feature Description Information is accessed through a series of commands called Standard Commands. Further capabilities are provided by the additional Extended Commands set. Both sets of commands, indicated by the general format Command), are used to read and write information within the control and status registers, as well as its data locations. Commands are sent from the system to the gauge using the I2C serial communications engine, and can be executed during application development, system manufacture, or end-equipment operation. The fuel gauge measures the charging and discharging of the battery by monitoring the voltage across a smallvalue sense resistor. When a cell is attached to the fuel gauge, cell impedance is computed based on cell current, cell open-circuit voltage (OCV), and cell voltage under loading conditions. The fuel gauge uses an integrated temperature sensor for estimating cell temperature. Alternatively, the host processor can provide temperature data for the fuel gauge. Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated Product Folder Links: bq27220 9 bq27220 SLUSCB7A – MARCH 2016 – REVISED APRIL 2016 www.ti.com Feature Description (continued) For more details, see the bq27220 Technical Reference Manual (SLUUBD4). The external temperature sensing is optimized with the use of a high accuracy negative temperature coefficient (NTC) thermistor with R25 = 10.0 kΩ ±1%. B25/85 = 3435K ± 1% (such as Semitec NTC 103AT) on the BIN pin. Alternatively, the bq27220 can also be configured to use its internal temperature sensor or receive temperature data from the host processor. The bq27220 uses temperature to monitor the battery-pack environment, which is used for fuel gauging and cell protection functionality. 7.3.1 Communications 7.3.1.1 I2C Interface The fuel gauge supports the standard I2C read, incremental read, quick read, one-byte write, and incremental write functions. The 7-bit device address (ADDR) is the most significant 7 bits of the hex address and is fixed as 1010101. The first 8 bits of the I2C protocol are, therefore, 0xAA or 0xAB for write or read, respectively. Host generated S ADDR[6:0] 0 A Gauge generated CMD [7:0] A DATA [7:0] A P S ADDR[6:0] 1 A (a) 1-byte write S ADDR[6:0] 0 A DATA [7:0] N P (b) quick read CMD [7:0] A Sr ADDR[6:0] 1 A DATA [7:0] N P (c) 1- byte read S ADDR[6:0] 0 A CMD [7:0] A Sr ADDR[6:0] 1 A DATA [7:0] A ... DATA [7:0] N P (d) incremental read S ADDR[6:0] 0 A CMD[7:0] A DATA [7:0] A DATA [7:0] A ... A P (e) incremental write (S = Start , Sr = Repeated Start , A = Acknowledge , N = No Acknowledge , and P = Stop). Figure 6. I2C Interface Read and Write Functions The quick read returns data at the address indicated by the address pointer. The address pointer, a register internal to the I2C communication engine, increments whenever data is acknowledged by the fuel gauge or the I2C master. “Quick writes” function in the same manner and are a convenient means of sending multiple bytes to consecutive command locations (such as two-byte commands that require two bytes of data). The following command sequences are not supported: Figure 7. Attempt to Write a Read-Only Address (NACK After Data Sent By Master) Figure 8. Attempt to Read an Address Above 0x6B (NACK Command) 7.3.1.2 I2C Time Out The I2C engine releases both SDA and SCL if the I2C bus is held low for 2 seconds. If the fuel gauge is holding the lines, releasing them frees them for the master to drive the lines. If an external condition is holding either of the lines low, the I2C engine enters the low-power SLEEP mode. 10 Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated Product Folder Links: bq27220 bq27220 www.ti.com SLUSCB7A – MARCH 2016 – REVISED APRIL 2016 Feature Description (continued) 7.3.1.3 I2C Command Waiting Time To ensure proper operation at 400 kHz, a t(BUF) ≥ 66 μs bus-free waiting time must be inserted between all packets addressed to the fuel gauge. In addition, if the SCL clock frequency (fSCL) is > 100 kHz, use individual 1byte write commands for proper data flow control. Figure 9 shows the standard waiting time required between issuing the control subcommand the reading the status result. For read-write standard commands, a minimum of 2 seconds is required to get the result updated. For read-only standard commands, there is no waiting time required, but the host must not issue any standard command more than two times per second. Otherwise, the gauge could result in a reset issue due to the expiration of the watchdog timer. S ADDR [6:0] 0 A CMD [7:0] A DATA [7:0] A P 66ms S ADDR [6:0] 0 A CMD [7:0] A DATA [7:0] A P 66ms S ADDR [6:0] 0 A CMD [7:0] A Sr ADDR [6:0] 1 A DATA [7:0] A DATA [7:0] N P 66ms N P 66ms Waiting time inserted between two 1-byte write packets for a subcommand and reading results (required for 100 kHz < fSCL £ 400 kHz) S ADDR [6:0] 0 A CMD [7:0] A S ADDR [6:0] 0 A CMD [7:0] A Sr DATA [7:0] ADDR [6:0] A 1 A DATA [7:0] DATA [7:0] A P A 66ms DATA [7:0] Waiting time inserted between incremental 2-byte write packet for a subcommand and reading results (acceptable for fSCL £ 100 kHz) S ADDR [6:0] DATA [7:0] 0 A A CMD [7:0] DATA [7:0] A Sr N P ADDR [6:0] 1 A DATA [7:0] A DATA [7:0] A 66ms Waiting time inserted after incremental read Figure 9. Standard Waiting Time 7.3.1.4 I2C Clock Stretching A clock stretch can occur during all modes of fuel gauge operation. In SLEEP mode, a short ≤ 100-µs clock stretch occurs on all I2C traffic as the device must wake-up to process the packet. In the other modes (INITIALIZATION, NORMAL), a ≤ 4-ms clock stretching period may occur within packets addressed for the fuel gauge as the I2C interface performs normal data flow control. 7.4 Device Functional Modes To minimize power consumption, the fuel gauge has several power modes: INITIALIZATION, NORMAL, and SLEEP. The fuel gauge passes automatically between these modes, depending upon the occurrence of specific events, though a system processor can initiate some of these modes directly. For more details, see the bq27220 Technical Reference Manual (SLUUBD4). Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated Product Folder Links: bq27220 11 bq27220 SLUSCB7A – MARCH 2016 – REVISED APRIL 2016 www.ti.com 8 Application and Implementation NOTE Information in the following application section is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality. 8.1 Application Information The bq27220 fuel gauge is a microcontroller peripheral that provides system-side or pack-side fuel gauging for single-cell Li-Ion batteries. The device requires minimal configuration and uses One-Time Programmable (OTP) Non-Volatile Memory (NVM). Battery fuel gauging with the fuel gauge requires connections only to PACK+ and PACK– for a removable battery pack or embedded battery circuit. To allow for optimal performance in the end application, special considerations must be taken to ensure minimization of measurement error through proper printed circuit board (PCB) board layout. Such requirements are detailed in Design Requirements. 8.2 Typical Applications Ext VCC EXT_VCC TP4 EXT_VCC J3 GND VDD VDD J4 R2 1.8 Meg PGND EXT_VCC BIN JP1 JP2 EXT_VCC R3 5.1k J2 J1 SDA SCL VSS R4 10.0k 4 3 2 1 R5 10.0k GPOUT GPOUT SDA SCL VDD U1 PGND Recommended to be connected GPOUT to a GPIO on the host. BIN C3 BAT VDD B3 A3 A2 SCL SDA SRP SRN C1 C2 A1 GPOUT B1 BIN VSS B2 TP5 C3 0.47 µF PGND PGND Cell+ Cell+ BIN Cell– 1 TP1 2 3 VDD C1 2.2 µF PGND Load+ TP2 J6 Load- J7 Pack+ Charger+ BIN J5 R8 10.0k C2 1 µF R1 TP3 0.01 ChargerPack+ PGND Figure 10. Typical Application for Pack-Side Using Low-Side Sensing 8.2.1 Design Requirements As shipped from the Texas Instruments factory, many bq27220 parameters in OTP NVM are left in the unprogrammed state (zero). This partially programmed configuration facilitates customization for each end application. Upon device reset, the contents of OTP are copied to associated volatile RAM-based data memory blocks. For proper operation, all parameters in RAM-based data memory require initialization — either by updating data memory parameters in a lab/evaluation situation or by programming the OTP for customer production. The bq27220 Technical Reference Manual (SLUUBD4) shows the default value and a typically expected value appropriate for most of applications. 12 Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated Product Folder Links: bq27220 bq27220 www.ti.com SLUSCB7A – MARCH 2016 – REVISED APRIL 2016 Typical Applications (continued) 8.2.2 Detailed Design Procedure 8.2.2.1 BAT Voltage Sense Input A ceramic capacitor at the input to the BAT pin is used to bypass AC voltage ripple to ground, greatly reducing its influence on battery voltage measurements. It proves most effective in applications with load profiles that exhibit high-frequency current pulses (that is, cell phones) but is recommended for use in all applications to reduce noise on this sensitive high-impedance measurement node. 8.2.2.2 Integrated LDO Capacitor The fuel gauge has an integrated LDO with an output on the VDD pin of approximately 1.8 V. A capacitor with a value of at least 2.2 μF should be connected between the VDD pin and VSS. The capacitor must be placed close to the gauge IC and have short traces to both the VDD pin and VSS. This regulator must not be used to provide power for other devices in the system. 8.2.2.3 Sense Resistor Selection Any variation encountered in the resistance present between the SRP and SRN pins of the fuel gauge will affect the resulting differential voltage, and derived current, that it senses. As such, it is recommended to select a sense resistor with minimal tolerance and temperature coefficient of resistance (TCR) characteristics. The standard recommendation based on the best compromise between performance and price is a 1% tolerance, 50ppm drift sense resistor with a 1-W power rating. 8.2.3 External Thermistor Support The fuel gauge temperature sensing circuitry is designed to work with a negative temperature coefficient-type (NTC) thermistor with a characteristic 10-kΩ resistance at room temperature (25°C). The default curve-fitting coefficients configured in the fuel gauge specifically assume a Semitec 103AT type thermistor profile and so that is the default recommendation for thermistor selection purposes. Moving to a separate thermistor resistance profile (for example, JT-2 or others) requires an update to the default thermistor coefficients, which can be modified in RAM to ensure highest accuracy temperature measurement performance. Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated Product Folder Links: bq27220 13 bq27220 SLUSCB7A – MARCH 2016 – REVISED APRIL 2016 www.ti.com Typical Applications (continued) 8.2.4 Application Curves 0.6% 0.45% 0.4% Voltage Accuracy Error Current Accuracy Error 0.5% 0.4% 0.3% 0.2% 0.1% 0 -0.1% -50 0.35% 0.3% 0.25% 0.2% 0.15% 0.1% 0.05% 0 50 Temperature (qC) 100 0 -60 -40 -20 0 20 40 Temperature (qC) D001 Figure 11. Current Accuracy Error vs. Temperature 60 80 100 D002 Figure 12. Voltage Accuracy Error vs. Temperature Internal Temperature Accuracy Error 0 -1% -2% -3% -4% -5% -6% -50 0 50 Temperature (qC) 100 D003 Figure 13. Internal Temperature Accuracy Error vs. Temperature 14 Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated Product Folder Links: bq27220 bq27220 www.ti.com SLUSCB7A – MARCH 2016 – REVISED APRIL 2016 9 Power Supply Recommendation 9.1 Power Supply Decoupling The battery connection on the BAT pin is used for two purposes: • To supply power to the fuel gauge, and • To provide an input for voltage measurement of the battery. A capacitor of value of at least 1 µF should be connected between BAT and VSS. The capacitor must be placed close to the gauge IC and have short traces to both the BAT pin and VSS. The fuel gauge has an integrated LDO with an output on the VDD pin of approximately 1.8 V. A capacitor of value of at least 2.2 µF should be connected between the VDD pin and VSS. The capacitor must be placed close to the gauge IC and have short traces to both the VDD pin and VSS. This regulator must not be used to provide power for other devices in the system. 10 Layout 10.1 Layout Guidelines • • • • A capacitor of value of at least 2.2 µF is connected between the VDD pin and VSS. The capacitor must be placed close to the gauge IC and have short traces to both the VDD pin and VSS. This regulator must not be used to provide power for other devices in the system. It is required to have a capacitor of at least 1.0 µF connect between the BAT pin and VSS if the connection between the battery pack and the gauge BAT pin has the potential to pick up noise. The capacitor should be placed close to the gauge IC and have short traces to both the BAT pin and VSS. If the external pullup resistors on the SCL and SDA lines will be disconnected from the host during low-power operation, it is recommended to use external 1-MΩ pulldown resistors to VSS to avoid floating inputs to the I2C engine. The value of the SCL and SDA pullup resistors should take into consideration the pullup voltage and the bus capacitance. Some recommended values, assuming a bus capacitance of 10 pF, can be seen in Table 1. Table 1. Recommended Values for SCL and SDA Pullup Resistors VPU RPU • • • • • • 1.8 V 3.3 V Range Typical Range Typical 400 Ω ≤ RPU ≤ 37.6 kΩ 10 kΩ 900 Ω ≤ RPU ≤ 29.2 kΩ 5.1 kΩ If the host is not using the GPOUT functionality, then it is recommended that GPOUT be connected to a GPIO of the host so that in the cases where the device is in SHUTDOWN, toggling GPOUT can wake the gauge from the SHUTDOWN state. If the battery pack thermistor is not connected to the BIN pin, the BIN pin should be pulled down to VSS with a 10-kΩ resistor. The BIN pin should not be shorted directly to VDD or VSS. The actual device ground is pin B2 (VSS). The SRP and SRN pins should be Kelvin connected to the RSENSE terminals. SRP to the battery pack side of RSENSE and SRN to the system side of the RSENSE. Kelvin connect the BAT pin to the battery PACKP terminal. Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated Product Folder Links: bq27220 15 bq27220 SLUSCB7A – MARCH 2016 – REVISED APRIL 2016 www.ti.com 10.2 Layout Example Kelvin connect SRP and SRN connections right at Rsense terminals RSENSE VSYSTEM If battery pack’s thermistor will not be connected to BIN pin, a 10-kΩ pulldown resistor should be connected to the BIN pin. SRP BAT SRN VDD CBAT C VDD VDD The BIN pin should not be shorted directly to VDD or VSS. Battery Pack PACK+ Li-Ion Cell TS + BIN Vpullup( do not pull to gauge VDD) VSS R BIN RSCL SCL GPOUT R SDA Place close to gauge IC. Trace to pin and VSS should be short SDA R THERM Protection IC PACK- RGPOUT NFET NFET SCL Via connects to Power Ground SDA GPOUT Figure 14. EVM Board Layout 16 Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated Product Folder Links: bq27220 bq27220 www.ti.com SLUSCB7A – MARCH 2016 – REVISED APRIL 2016 11 Device and Documentation Support 11.1 Documentation Support 11.1.1 Related Documentation • bq27220 Technical Reference Manual (SLUUBD4) • Quickstart Guide for bq27220 (SLUUAP7) • Single Cell Gas Gauge Circuit Design (SLUA456) • Key Design Considerations for the bq27500 and bq27501 (SLUA439) • ESD and RF Mitigation in Handheld Battery Electronics (SLUA460) 11.2 Community Resources The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of Use. TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help solve problems with fellow engineers. Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and contact information for technical support. 11.3 Trademarks NanoFree, E2E are trademarks of Texas Instruments. I2C is a trademark of NXP Semiconductors, N.V. All other trademarks are the property of their respective owners. 11.4 Electrostatic Discharge Caution This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. 11.5 Glossary SLYZ022 — TI Glossary. This glossary lists and explains terms, acronyms, and definitions. 12 Mechanical, Packaging, and Orderable Information The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of this document. For browser-based versions of this data sheet, refer to the left-hand navigation. Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated Product Folder Links: bq27220 17 PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2020 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) (6) BQ27220YZFR ACTIVE DSBGA YZF 9 3000 RoHS & Green SNAGCU Level-1-260C-UNLIM -40 to 85 BQ27220 BQ27220YZFT ACTIVE DSBGA YZF 9 250 RoHS & Green SNAGCU Level-1-260C-UNLIM -40 to 85 BQ27220 (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) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of