bq24230 bq24232 www.ti.com .......................................................................................................................................... SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 USB-FRIENDLY LITHIUM-ION BATTERY CHARGER AND POWER-PATH MANAGEMENT IC FEATURES 1 • • • Proprietary Start-Up Sequence Limits Inrush Current Status Indication – Charging/Done, Power Good Small 3 mm × 3 mm 16-Lead QFN Package APPLICATIONS • • Bluetooth™ Devices Low-Power Handheld Devices TYPICAL APPLICATION CIRCUIT 1 kΩ 9 CHG IN 7 Adaptor PGOOD 1 kΩ 13 DC SYSTEM OUT 10 11 1mF GND 4.7mF EN2 5 BAT 2 3 TS 1 4.7mF TD ILIM 12 ISET EN1 6 TEMP 16 CE PACK+ TMR 15 bq24230 VSS 4 8 14 • Fully Compliant USB Charger – Selectable 100-mA and 500-mA Maximum Input Current – 100-mA Maximum Current Limit Ensures Compliance to USB-IF Standard – Input-based Dynamic Power Management (VIN-DPM) for Protection Against Poor USB Sources • 28-V Input Rating With Overvoltage Protection • Integrated Dynamic Power-Path Management (DPPM) Function Simultaneously and Independently Powers the System and Charges the Battery • Supports up to 500-mA Charge Current With Current Monitoring Output (ISET) • Programmable Input Current Limit up to 500 mA for Wall Adapters • Programmable Termination Current (bq24232) • Programmable Precharge and Fast-Charge Safety Timers • Reverse Current, Short-Circuit, and Thermal Protection • NTC Thermistor Input 2 2.94 kΩ 4.32 kΩ PACK- DESCRIPTION The bq2423x series of devices are highly integrated Li-ion linear chargers and system power-path management devices targeted at space-limited portable applications. The devices operate from either a USB port or ac adapter and support charge currents between 25 mA and 500 mA. The high-input-voltage range with input overvoltage protection supports low-cost, unregulated adapters. The USB input current limit accuracy and start-up sequence allow the bq2423x to meet USB-IF inrush current specification. Additionally, the input dynamic power management (VIN-DPM) prevents the charger from crashing poorly designed or incorrectly configured USB sources. The bq2423x features dynamic power-path management (DPPM) that powers the system while simultaneously and independently charging the battery. The DPPM circuit reduces the charge current when the input current limit causes the system output to fall to the DPPM threshold, thus supplying the system load at all times while monitoring the charge current separately. This feature reduces the number of charge and discharge cycles on the battery, allows for proper charge termination, and enables the system to run with a defective or absent battery pack. Additionally, this enables instant system turn-on even with a totally discharged battery. The power-path management architecture also permits the battery to supplement the system current requirements when the adapter cannot deliver the peak system currents, enabling the use of a smaller adapter. 1 2 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. Bluetooth is a trademark of Bluetooth SIG, Inc.. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2008, Texas Instruments Incorporated bq24230 bq24232 SLUS821A – OCTOBER 2008 – REVISED DECEMBER 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 battery is charged in three phases: conditioning, constant current, and constant voltage. In all charge phases, an internal control loop monitors the IC junction temperature and reduces the charge current if the internal temperature threshold is exceeded. The charger power stage and charge current sense functions are fully integrated. The charger function has high-accuracy current and voltage regulation loops, charge status display, and charge termination. The input current limit and charge current are programmable using external resistors. ORDERING INFORMATION PART NUMBER (1) (2) VOVP VOUT(REG) VDPM OPTIONAL FUNCTION MARKING bq24230RGTR 6.6 V 4.4 V VO(REG) – 100 mV TD CGN bq24230RGTT 6.6 V 4.4 V VO(REG) – 100 mV TD CGN bq24232RGTR 10.5 V 4.4 V VO(REG) – 100 mV ITERM NXK bq24232RGTT 10.5 V 4.4 V VO(REG) – 100 mV ITERM NXK (1) (2) The RGT package is available in the following options: R - taped and reeled in quantities of 3000 devices per reel. T - taped and reeled in quantities of 250 devices per reel. This product is RoHS compatible, including a lead concentration that does not exceed 0.1% of total product weight, and is suitable for use in specified lead-free soldering processes. In addition, this product uses package materials that do not contain halogens, including bromine (Br) or antimony (Sb) above 0.1% of total product weight. ABSOLUTE MAXIMUM RATINGS (1) over the 0°C to 125°C operating free-air temperature range (unless otherwise noted) VI II IO Input voltage Input current Output current (continuous) Output sink current VALUE UNIT IN (with respect to VSS) –0.3 to 28 V OUT (with respect to VSS) –0.3 to 7 V BAT (with respect to VSS) –0.3 to 5 V EN1, EN2, CE, TS, ISET, PGOOD, CHG, ILIM, TMR, TD, ITERM (with respect to VSS) –0.3 to 7 V IN 600 mA OUT 600 mA BAT (Discharge mode) 600 mA CHG, PGOOD 15 mA TJ Junction temperature –40 to 150 °C Tstg Storage temperature –65 to 150 °C (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. All voltage values are with respect to the network ground terminal unless otherwise noted. DISSIPATION RATINGS (1) (1) (2) 2 PACKAGE (2) RθJA RθJC RGT (1) 39.47 °C/W 2.4 °C/W POWER RATING TA ≤ 25°C TA = 85°C 2.3 W 225 mW This data is based on using the JEDEC High-K board and the exposed die pad is connected to a Cu pad on the board. The pad is connected to the ground plane by a 2x3 via matrix. For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI website at www.ti.com. Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 bq24230 bq24232 www.ti.com .......................................................................................................................................... SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 RECOMMENDED OPERATING CONDITIONS MIN IN voltage range VI IN operating voltage range MAX UNIT 4.35 26 V '230 4.35 6.4 V '232 4.35 10.2 IIN Input current, IN pin 500 mA IOUT Current, OUT pin 500 mA IBAT Current, BAT pin (discharging) 500 mA ICHG Current, BAT pin (charging) 500 mA TJ Junction temperature –40 125 °C RILIM Maximum input current programming resistor 3.1 7.8 kΩ RISET Fast-charge current programming resistor 1.8 36 kΩ RTMR Timer programming resistor 18 72 kΩ RITERM Termination programming resistor 0 15 kΩ MAX UNIT '232 ELECTRICAL CHARACTERISTICS over operating free-air temperature range (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP 3.3 INPUT UVLO Undervoltage lockout VIN: 0 V → 4 V 3.2 Vhys(UVLO) Hysteresis on UVLO VIN: 4 V → 0 V 200 VIN(DT) Input power detection threshold Input power detected when VIN > VBAT + VIN(DT) VBAT = 3.6 V, VIN: 3.5 V → 4 V 55 Vhys(INDT) Hysteresis on VIN(DT) VBAT = 3.6 V, VIN: 4 V → 3.5 V 20 tDGL(PGOOD) Deglitch time, input power detected status Time measured from VIN: 0 V → 5 V 1-µs rise time to PGOOD = LO VOVP Input overvoltage protection threshold ('230) VIN: 5 V → 7 V 6.4 6.6 6.8 ('232) VIN: 5 V → 11 V 10.2 10.5 10.8 Vhys(OVP) Hysteresis on OVP ('230) VIN: 7 V → 5V 110 ('232) VIN: 11 V → 5 V 175 tDGL(OVP) tREC(OVP) V mV 130 mV mV 2 ms V mV 50 µs 2 ms VIN > UVLO and VIN > VBAT+VIN(DT) 1.3 mA VIN > UVLO and VIN > VBAT+VIN(DT) 520 mV Input overvoltage blanking time Input overvoltage recovery time 80 3.4 300 Time measured from VIN: 11 V → 5 V 1 µs fall time to PGOOD = LO ILIM, TEST ISET SHORT CIRCUIT ISC Current source VSC QUIESCENT CURRENT CE = LO or HI, input power not detected, no load on OUT pin 6.5 µA EN1= HI, EN2=HI, VIN = 6 V, TJ=85°C 50 µA EN1= HI, EN2=HI, VIN = 10 V, TJ=85°C 200 Active supply current, IN pin CE = LO, VIN = 6 V, no load on OUT pin, VBAT > VBAT(REG), (EN1, EN2) ≠ (HI, HI) 1.5 mA VDO(IN-OUT) VIN – VOUT VIN = 4.3 V, IIN = 500 mA, VBAT = 4.2 V 237.5 mV VDO(BAT-OUT) VBAT – VOUT IOUT = 500 mA, VIN = 0 V, VBAT > 3 V 62.5 mV VO(REG) OUT pin voltage regulation VIN > VOUT + VDO (IN-OUT) 4.3 4.4 4.5 V EN1 = LO, EN2 = LO 90 95 100 EN1 = HI, EN2 = LO 450 475 500 IBAT(PDWN) Sleep current into BAT pin IIN(STDBY) Standby current into IN pin ICC POWER PATH IINmax Maximum input current KILIM Maximum input current factor IINmax Programmable input current limit range 150.0 EN2 = HI, EN1 = LO KILIM/RILIM 1320 EN2 = HI, EN1 = LO, RILIM = 3.1 kΩ to 7.8 kΩ 200 1470 A 1620 AΩ 500 mA Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 mA 3 bq24230 bq24232 SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 .......................................................................................................................................... www.ti.com ELECTRICAL CHARACTERISTICS (continued) over operating free-air temperature range (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT 4.35 4.50 4.63 V VO(REG) – 180 mV VO(REG) – 100 mV VO(REG) – 30 mV V VIN-DPM Input voltage threshold when input current is reduced VDPPM Output voltage threshold when charging current is reduced VBSUP1 Enter battery supplement mode VBAT = 3.6 V, RILIM = 1.5 kΩ, RLOAD = 10 Ω →2 Ω VOUT ≤ VBAT –40 mV V VBSUP2 Exit battery supplement mode VBAT = 3.6 V, RILIM = 1.5 kΩ, RLOAD = 2 Ω →10 Ω VOUT ≥ VBAT–20 mV V VO(SC1) Output short-circuit detection threshold, power-on VIN > UVLO and VIN > VBAT+VIN(DT) Output short-circuit detection threshold, supplement mode VBAT – VOUT > VO(SC2) indicates short circuit VIN > UVLO and VIN > VBAT+VIN(DT) VO(SC2) tDGL(SC2) Deglitch time, supplement mode short circuit tREC(SC2) Recovery time, supplement mode short circuit EN2 = LO, EN1 = X 0.8 0.9 1 200 250 300 V mV 250 µs 60 ms BATTERY CHARGER IBAT(SC) Source current for BAT pin short-circuit detection VBAT = 1.5 V VBAT(SC) BAT pin short-circuit detection threshold VBAT rising VBAT(REG) Battery charge voltage VLOWV Precharge to fast-charge transition threshold tDGL1(LOWV) Deglitch time on precharge to fast-charge transition 25 ms tDGL2(LOWV) Deglitch time on fast-charge to precharge transition 25 ms VIN > UVLO and VIN > VBAT + VIN(DT) Battery fast-charge current range VBAT(REG) > VBAT > VLOWV, VIN = 5 V, CE = LO, EN1 = LO, EN2 = HI Battery fast-charge current CE = LO, EN1= LO, EN2 = HI, VBAT > VLOWV, VIN = 5 V, IINmax > ICHG, no load on OUT pin, thermal loop and DPM loop not active KISET Fast-charge current factor 25 mA ≥ ICHG≥ 500 mA IPRECHG Precharge current 2.5 mA ≥ IPRECHG≥ 30 mA ICHG ITERM Termination comparator threshold for termination detection ITERM Termination current threshold factor (bq24232) IBIAS(ITERM) Current for external termination-setting resistor KITERM K factor for termination detection threshold (externally set) (bq24232) IBIAS(ITERM) Current for external termination_setting resistor (bq24232) tDGL(TERM) Deglitch time, termination detected VRCH 4 Recharge detection threshold 4 7.5 11 mA 1.6 1.8 2 V 4.16 4.20 4.24 V 2.9 3 3.1 ms 25 500 KISET/RISET mA A 797 870 975 AΩ AΩ 70 88 106 CE = LO, (EN1,EN2) ≠ (LO,LO), VBAT > VRCH, t < tMAXCH, VIN = 5 V, DPM loop and thermal loop not active 0.09*ICHG 0.1*ICHG 0.11*ICHG CE = LO, (EN1,EN2) = (LO,LO), VBAT > VRCH, t < tMAXCH, VIN = 5 V, DPM loop and thermal loop not active 0.027*ICHG 0.033*ICHG 0.040*ICHG A ITERM = 0% to 50% of ICHG KITERM*RITERM/RISET 72 75 78 CE = LO, (EN1,EN2) ≠ (LO,LO), VBAT > VRCH, t < tMAXCH, VIN = 5 V, DPM loop and thermal loop not active 0.024 0.030 0.036 CE = LO, (EN1,EN2) = (LO,LO), VBAT > VRCH, t < tMAXCH, VIN = 5 V, DPM loop and thermal loop not active 0.009 0.010 0.011 72 75 78 VO(REG) –140 mV VO(REG) –100 mV A µA A µA 25 VIN > UVLO and VIN > VBAT+VIN(DT) Submit Documentation Feedback ms VO(REG) –60 mV V Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 bq24230 bq24232 www.ti.com 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SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 ELECTRICAL CHARACTERISTICS (continued) over operating free-air temperature range (unless otherwise noted) PARAMETER TEST CONDITIONS tDGL(RCH) Deglitch time, recharge threshold detected tDGL(NO-IN) Delay time, input power loss to charger turnoff VBAT = 3.6 V. Time measured from VIN: 5 V → 3 V 1-µs fall time IBAT(DET) Sink current for battery detection VBAT=2.5 V tDET Battery detection timer BAT high or low MIN 5 TYP MAX UNIT 62.5 ms 20 ms 7.5 10 250 mA ms BATTERY CHARGING TIMERS tPRECHG Precharge safety timer value TMR = floating 1440 1800 2160 s tMAXCHG Charge safety timer value TMR = floating 14400 18000 21600 s tPRECHG Precharge safety timer value 18 kΩ < RTMR < 72 kΩ RTMR × KTMR tMAXCHG Charge safety timer value 18 kΩ < RTMR < 72 kΩ 10×RTMR ×KTMR KTMR Timer factor s s 30 40 50 s/kΩ 72 75 78 µA 270 300 330 mV BATTERY-PACK NTC MONITOR (1) INTC NTC bias current VIN > UVLO and VIN > VBAT+VIN(DT) VHOT High-temperature trip point Battery charging, VTS Falling VHYS(HOT) Hysteresis on high trip point Battery charging, VTS Rising from VHOT VCOLD Low-temperature trip point Battery charging, VTS Rising VHYS(COLD) Hysteresis on low trip point Battery charging, VTS Falling from VCOLD tDGL(TS) Deglitch time, pack temperature fault detection Battery charging, VTS Falling VDIS(TS) TS function disable threshold TS unconnected 30 2000 2100 mV 2200 mV 300 mV 50 ms VIN-200 mV V 125 °C 155 °C 20 °C THERMAL REGULATION TJ(REG) Temperature regulation limit TJ(OFF) Thermal shutdown temperature TJ(OFF-HYS) Thermal shutdown hysteresis TJ rising LOGIC LEVELS ON EN1, EN2, CE, TD VIL Logic LOW input voltage 0 0.4 VIH Logic HIGH input voltage 1.4 6.0 V V IIL Input sink current VIL = 0 V 1 µA IIH Input source current VIH = 1.4 V 10 µA ISINK = 5 mA 0.4 V LOGIC LEVELS ON PGOOD, CHG VOL (1) Output LOW voltage These numbers set trip points of 0°C and 50°C while charging, with 3°C hysteresis on the trip points, with a Vishay Type 2 curve NTC with an R25 of 10 kΩ. Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 5 bq24230 bq24232 SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 .......................................................................................................................................... www.ti.com 4 9 6 7 EN2 EN1 PGOOD 5 8 1 BAT 2 BAT 3 CE 4 ISET ITERM TMR IN 13 bq24232 5 6 7 12 ILIM 11 OUT 10 OUT 9 CHG 8 VSS 11 10 TS 14 PGOOD bq24230 3 ILIM OUT OUT CHG 16 15 EN1 2 VSS TS BAT BAT CE 16 15 14 13 1 12 EN2 ISET TD TMR IN RGT PACKAGE (Top View) TERMINAL FUNCTIONS TERMINAL NAME NUMBER I/O DESCRIPTION '230 '232 1 1 I BAT 2,3 2, 3 I/O CE 4 4 I EN2 5 5 I EN1 6 6 I PGOOD 7 7 O Open-drain Power Good Status Indication Output. PGOOD pulls to VSS when a valid input source is detected. PGOOD is high-impedance when the input power is not within specified limits. Connect PGOOD to the desired logic voltage rail using a 1-kΩ – 100-kΩ resistor, or use with an LED for visual indication. VSS 8 8 – Ground. Connect to the thermal pad and to the ground rail of the circuit. CHG 9 9 O Open-Drain Charging Status Indication Output. CHG pulls to VSS when the battery is charging. CHG is high impedance when charging is complete and when charger is disabled. OUT 10,11 10, 11 O System Supply Output. OUT provides a regulated output when the input is below the OVP threshold and above the regulation voltage. When the input is out of the operation range, OUT is connected to VBAT. Connect OUT to the system load. Bypass OUT to VSS with a 4.7-µF to 47-µF ceramic capacitor. ILIM 12 12 I Adjustable Current Limit Programming Input. Connect a 3.1-kΩ to 7.8-kΩ resistor from ILIM to VSS to program the maximum input current (EN2=1, EN1=0). The input current includes the system load and the battery charge current. IN 13 13 I Input Power Connection. Connect IN to the connected to external DC supply (AC adapter or USB port). The input operating range is 4.35 V to 6.6 V. The input can accept voltages up to 26 V without damage but operation is suspended. Connect bypass capacitor 1 µF to 10 µF to VSS. TMR 14 14 I Timer Programming Input. TMR controls the precharge and fast-charge safety timers. Connect TMR to VSS to disable all safety timers. Connect a 18-kΩ to 72-kΩ resistor between TMR and VSS to program the timers a desired length. Leave TMR unconnected to set the timers to the 5-hour fast charge and 30-minute precharge default timer values. TD 15 - I Termination Dsable Input. Connect TD high to disable charger termination. Connect TD to VSS to enable charger termination. TD is checked during start-up only and cannot be changed during operation. See the TD section in this data sheet for a description of the behavior when termination is disabled. TD is internally pulled down to VSS with ~285 kΩ. Do not leave TD unconnected to ensure proper operation. - 15 I Termination Current Programming Input. Connect a 0-Ω to 15-kΩ resistor from ITERM to VSS to program the termination current. Leave ITERM unconnected to set the termination current to the internal default 10% threshold. 16 16 I/O Fast-Charge Current Programming Input. Connect a 3-kΩ to 36-kΩ resistor from ISET to VSS to program the fast-charge current level. Charging is disabled if ISET is left unconnected. While charging, the voltage at ISET reflects the actual charging current and can be used to monitor charge current. See the CHARGE CURRENT TRANSLATOR section for more details. – An internal electrical connection exists between the exposed thermal pad and the VSS pin of the device. The thermal pad must be connected to the same potential as the VSS pin on the printed-circuit board. Do not use the thermal pad as the primary ground input for the device. The VSS pin must be connected to ground at all times. TS ITERM ISET Thermal Pad 6 External NTC Thermistor Input. Connect the TS input to the NTC thermistor in the battery pack. TS monitors a 10-kΩ NTC thermistor. For applications that do not utilize the TS function, connect a 10-kΩ fixed resistor from TS to VSS to maintain a valid voltage level on TS. Charger Power Stage Output and Battery Voltage Sense Input. Connect BAT to the positive terminal of the battery. Bypass BAT to VSS with a 4.7-µF to 47-µF ceramic capacitor. Charge Enable Active-Low Input. Connect CE to a high logic level to place the battery charger in standby mode. In standby mode, OUT is active and battery supplement mode is still available. Connect CE to a low logic level to enable the battery charger. CE is internally pulled down with ~285 kΩ. Do not leave CE unconnected to ensure proper operation. Input Current Limit Configuration Inputs. Use EN1 and EN2 control the maximum input current and enable USB compliance. See Table 2 for the description of the operation states. EN1 and EN2 are internally pulled down with ~285 kΩ. Do not leave EN1 or EN2 unconnected to ensure proper operation. Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 bq24230 bq24232 www.ti.com .......................................................................................................................................... SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 Table 1. EN1/EN2 Settings EN2 EN1 Maximum input current into IN pin 0 0 100 mA. USB100 mode 0 1 500 mA. USB500 mode 1 0 Set by an external resistor from ILIM to VSS 1 1 Standby (USB suspend mode) SIMPLIFIED BLOCK DIAGRAM 250 mV VO (SC1) VBAT OUT- SC1 tDGL(SC2) OUT- SC 2 Q1 IN OUT EN2 Short Detect 225 mV Precharge 2. 25 . V Fastcharge VIN-LOW USB100 USB500 ILIM V REF-ILIM USB-susp ISET TJ TJ (REG) Short Detect VDPPM VOUT VO (REG) Q2 VBAT(REG) EN2 EN1 BAT V OUT CHARGEPUMP I BIAS-ITERM 40 mV Supplement V LOWV 225 mV ITERM bq24232 VRCH VBAT(SC) tDGL(RCH) tDGL2(LOWV) tDGL(TERM) VIN tDGL1(LOWV) ITERM- floating ~3 V BAT-SC VBAT+VIN-DT t DGL (NO-IN) t DGL(PGOOD) VUVLO I NTC V HOT Charge Control TS t DGL (TS ) V COLD V OVP t BLK (OVP) VDIS(TS) EN1 EN2 USB Suspend TD bq24230 CE Halt timers CHG VIPRECHG V CHG I VISET Dynamically Controlled Oscillator Reset timers PGOOD Fast- Charge Timer Timer fault TMR Pre -Charge Timer ~100 mV Timers disabled Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 7 bq24230 bq24232 SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 .......................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS Typical Application Circuit, EN1=0, EN2=1, TA=25°C, unless otherwise noted. ADAPTER PLUG-IN WITH BATTERY CONNECTED RLOAD = 25Ω VIN 5 V/div VOUT 4.4 V BATTERY DETECTION -- INSERTION VCHG 5 V/div BATTERY DETECTION -- REMOVAL VCHG 2 V/div 1 V/div VBAT 4V 2 V/div VBAT VBAT Battery Inserted VPGOOD 200 mA/div Battery Removed Battery Detection Mode Battery Detection Mode Battery Supplying Load Mandatory Precharge 200 mA/div IBAT Charging Initiated 100 mA/div IBAT Fastcharge IBAT 2 V/div 4 ms/div 400 ms/div 400 ms/div Figure 1. Figure 2. Figure 3. ENTERING AND EXITING DPPM MODE RLOAD = 25Ω to 9Ω ENTERING AND EXITING BATTERY SUPPLEMENT MODE RLOAD = 25Ω to 4.5Ω CHARGER ON/OFF USING CE ILOAD 500 mA/div 500 mA/div ILOAD IBAT 5 V/div 500 mA/div VBAT 3.6V VOUT 4.4 V VOUT 4.4 V 5 V/div VCHG Supplement Mode 200 mA/div IBAT VCE 500 mV/div 200 mV/div 200 mV/div IBAT VBAT 3.9 V Mandatory Precharge 2 ms/div 400 ms/div Figure 4. OVP FAULT VIN = 6V to 15V RLOAD = 25Ω 100 mA/div 10 ms/div Figure 5. Figure 6. THERMAL REGULATION DROPOUT VOLTAGE vs TEMPERATURE 250 0.35 IL = 500 mA Dropout Voltage - VIN-VOUT 200 mA/div IBAT - mA 200 IBAT 150 100 VOUT 4.4 V VBAT 4.2 V 200 mV/div 50 0.25 0.20 0.15 0.10 0.05 40 ms/div Figure 7. 8 0.30 10 V/div VIN 0 120 0 125 130 135 140 TA - Free-Air Temperature - °C 145 Figure 8. Submit Documentation Feedback 0 25 100 50 75 TJ - Junction Temperature - °C 125 Figure 9. Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 bq24230 bq24232 www.ti.com .......................................................................................................................................... SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 TYPICAL CHARACTERISTICS (continued) Typical Application Circuit, EN1=0, EN2=1, TA=25°C, unless otherwise noted. DROPOUT VOLTAGE vs TEMPERATURE OUTPUT REGULATION VOLTAGE vs TEMPERATURE 60 4.45 4.210 VIN = 5 V, IL = 500 mA IL = 500 mA 40 VBAT = 3 V 30 VBAT = 3.9 V 20 VBAT - Regulation Voltage - V 4.43 VO - Output Voltage - V 4.40 4.38 4.35 4.33 10 4.30 0 0 50 75 100 25 TJ - Junction Temperature - °C 125 0 75 100 125 4.200 4.195 4.190 4.185 4.180 0 25 50 75 100 125 150 TJ - Junction Temperature - °C TJ - Junction Temperature - °C Figure 10. Figure 11. Figure 12. OVERVOLTAGE PROTECTION THRESHOLD vs TEMPERATURE bq24230 OVERVOLTAGE PROTECTION THRESHOLD vs TEMPERATURE bq24232 INPUT CURRENT LIMIT THRESHOLD vs INPUT VOLTAGE 6.70 800 10.70 10.5 V VOVP - Output Voltage Threshold - V 6.6 V 6.65 VI Rising 6.60 6.55 VI Falling 6.50 6.45 0 50 25 4.205 10.65 700 10.60 VI Rising ILIM - Input Current - mA Dropout Voltage - VBAT-VOUT 50 VOVP - Output Voltage Threshold - V BATTERY REGULATION VOLTAGE vs TEMPERATURE 10.55 10.50 10.45 VI Falling 10.40 10.35 10.30 125 USB500 400 300 200 USB100 0 0 25 75 50 100 TJ - Junction Temperature - °C Figure 13. 5 125 6 7 8 9 VI - Input Voltage - V Figure 14. FAST-CHARGE CURRENT vs BATTERY VOLTAGE 10 Figure 15. PRECHARGE CURRENT vs BATTERY VOLTAGE 31.5 310 RISET = 3.3 kW RISET = 3.3 kW 305 31 IBAT - Precharge Current - A IBAT - Fast Charge Current - A 500 100 10.25 10.20 25 50 75 100 TJ - Junction Temperature - °C 600 300 295 290 285 280 30.5 30 29.5 29 28.5 3 3.2 3.4 3.6 3.8 4 VBAT - Battery Voltage - V 4.2 2 2.2 2.4 2.6 2.8 VBAT - Battery Voltage - V Figure 16. 3 Figure 17. Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 9 bq24230 bq24232 SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 .......................................................................................................................................... www.ti.com APPLICATION CIRCUITS VIN = VUVLO to VOVP , IFASTCHG = 200 mA, IIN(MAX) = 500 mA, Battery Temperature Charge Range 0°C to 50°C, 6.25-hour Fast Charge Safety Timer. R4 1.5 kΩ R5 1.5 kΩ DC+ IN C HG Adaptor PGOOD SYSTEM OUT C1 1μF GND C2 4.7μF VSS bq24230 HOST EN2 EN1 TS TD CE BAT TEMP PACK+ C3 4.7μF PACK - R1 56.2 kΩ R2 2.94 kΩ R3 4.35 kΩ Figure 18. Using the bq24230 in a Host Controlled Charger Application 10 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 bq24230 bq24232 www.ti.com .......................................................................................................................................... SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 VIN = VUVLO to VOVP , IFASTCHG = 200 mA, IIN(MAX) = 500 mA, 25-mA Termination Current, ISET mode (EN1=0, EN2=1), Battery Temperature Charge Range 0°C to 50°C, 6.25-hour Fast Charge Safety Timer. R5 1.5 kΩ R6 1.5 kΩ Adaptor DC+ IN CH G PGOOD SYSTEM OUT C1 1 μF GND C2 4.7μF VSS bq 24232 EN 2 EN 1 TS CE BAT PACK - R1 3.57 kΩ IS E T IT E R M TEMP TMR C3 4.7 μF IL IM PACK + R2 2.94 kΩ R4 56 .2 kΩ R3 4 .32 kΩ Figure 19. Using the bq24232 in a Stand-Alone Charger Application Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 11 bq24230 bq24232 SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 .......................................................................................................................................... www.ti.com EXPLANATION OF DEGLITCH TIMES AND COMPARATOR HYSTERESIS Figures not to scale VOVP VOVP - Vhys(OVP) VIN Typical Input Voltage Operating Range t < tDGL(OVP) VBAT + VIN(DT) VBAT + VIN(DT) - Vhys(INDT) UVLO UVLO - Vhys(UVLO) PGOOD tDGL(PGOOD) tDGL(OVP) tDGL(NO-IN) tDGL(PGOOD) Figure 20. Power Up, Power Down tDGL1(LOWV) VBAT VLOWV t < tDGL1(LOWV) tDGL1(LOWV) tDGL2(LOWV) ICHG Fast-Charge Fast-Charge IPRE-CHG t < tDGL2(LOWV) Pre-Charge Pre-Charge Figure 21. Pre- to Fast-Charge, Fast- to Precharge Transition – tDGL1(LOWV), tDGL2(LOWV) VBAT VRCH Re-Charge t < tDGL(RCH) tDGL(RCH) Figure 22. Recharge – tDGL(RCH) 12 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 bq24230 bq24232 www.ti.com .......................................................................................................................................... SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 Turn Q2 OFF Force Q2 ON tREC(SC2) Turn Q2 OFF tREC(SC2) Force Q2 ON VBAT - VOUT Recover VO(SC2) t < tDGL(SC2) tDGL(SC2) tDGL(SC2) t < tDGL(SC2) Figure 23. OUT Short-Circuit – Supplement Mode VCOLD VCOLD - Vhys(COLD) t < tDGL(TS) Suspend Charging tDGL(TS) VTS Resume Charging VHOT - Vhys(HOT) VHOT Figure 24. Battery Pack Temperature Sensing – TS Pin. Battery Temperature Increasing DETAILED FUNCTIONAL DESCRIPTION The bq2423x devices are integrated Li-ion linear chargers and system power-path management devices targeted at space-limited portable applications. The device powers the system while simultaneously and independently charging the battery. This feature reduces the number of charge and discharge cycles on the battery, allows for proper charge termination, and enables the system to run with a defective or absent battery pack. It also allows instant system turnon even with a totally discharged battery. The input power source for charging the battery and running the system can be an AC adapter or a USB port. The devices feature dynamic power-path management (DPPM), which shares the source current between the system and battery charging and automatically reduces the charging current if the system load increases. When charging from a USB port, the input dynamic power management (VIN-DPM) circuit reduces the input current limit if the input voltage falls below a threshold, preventing the USB port from crashing. The power-path architecture also permits the battery to supplement the system current requirements when the adapter cannot deliver the peak system currents. Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 13 bq24230 bq24232 SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 .......................................................................................................................................... www.ti.com UNDERVOLTAGE LOCKOUT The bq2423x family remains in power-down mode when the input voltage at the IN pin is below the undervoltage lockout (UVLO) threshold. During the power-down mode, the host commands at the control inputs (CE, EN1 and EN2) are ignored. The Q1 FET connected between IN and OUT pins is off, and the status outputs CHG and PGOOD are high impedance. The Q2 FET that connects BAT to OUT is ON. During power-down mode, the VOUT(SC2) circuitry is active and monitors for overload conditions on OUT. POWER ON When VIN exceeds the UVLO threshold, the bq2423x powers up. While VIN is below VBAT + VIN(DT), the host commands at the control inputs (CE, EN1, and EN2) are ignored. The Q1 FET connected between IN and OUT pins is off, and the status outputs CHG and PGOOD are high impedance. The Q2 FET that connects BAT to OUT is ON. During this mode, the VOUT(SC2) circuitry is active and monitors for overload conditions on OUT. When VIN rises above VBAT + VIN(DT), PGOOD is low to indicate that the valid power status and the CE, EN1, and EN2 inputs are read. The device enters standby mode whenever (EN1, EN2) = (1, 1) or if an input overvoltage condition occurs. In standby mode, Q1 is OFF and Q2 is ON. (If SYSOFF is high, FET Q2 is off). During standby mode, the VOUT(SC2) circuitry is active and monitors for overload conditions on OUT. When the input voltage at IN is within the valid range: VIN > UVLO AND VIN > VBAT + VIN(DT) AND VIN < VOVP, and the EN1 and EN2 pins indicate that the USB suspend mode is not enabled [(EN1, EN2) ≠ (HI, HI)], all internal timers and other circuit blocks are activated. The device checks for short circuits at the ISET and ILIM pins. If no short conditions exists, the device switches on the input FET Q1 with a 100-mA current limit to check for a short circuit at OUT. If VOUT rises above VSC, the FET Q1 switches to the current-limit threshold set by EN1, EN2, and RILIM and the device enters normal operation where the system is powered by the input source (Q1 is on), and the device continuously monitors the status of CE, EN1, and EN2 as well as the input voltage conditions. 14 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 bq24230 bq24232 www.ti.com .......................................................................................................................................... SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 Begin Startup I IN (MAX) 100 mA PGOOD = Hi -Z CHG = Hi -Z BATTFET ON Yes V OUT short ? V UVLO<V IN <V OVP and V IN >V BAT+V IN(DT) No No Yes Input Current Limit set by EN 1 and EN2 PGOOD = Low Yes EN 1= EN 2 =1 No CE = Low No Yes Yes ILIM or ISET short ? Begin Charging No Figure 25. Start-up Flow Diagram POWER-PATH MANAGEMENT The bq2423x features an OUT output that powers the external load connected to the battery. This output is active whenever a source is connected to IN or BAT. The following sections discuss the behavior of OUT with a source connected to IN to charge the battery and a battery source only. INPUT SOURCE CONNECTED – ADAPTER or USB With a source connected, the power-path management circuitry of the bq2423x monitors the input current continuously. The OUT output is regulated to a fixed voltage (VO(REG)). The current into IN is shared between charging the battery and powering the system load at OUT. The bq2423x has internal selectable current limits of 100 mA (USB100) and 500 mA (USB500) for charging from USB ports, as well as a resistor-programmable input current limit. The bq2423x is USB-IF compliant for the inrush current testing. The USB spec allows up to 10µF to be hard-started, which establishes a 50 µF as the maximum inrush charge value when exceeding 100 mA. The input current limit for the bq2423x prevents the input current from exceeding this limit, even with system capacitances greater than 10 µF. Note that the input capacitance to the device must be selected small enough to prevent a violation (<10 µF), as this current is not limited. Figure 26 demonstrates the startup of the bq2423x and compares it to the USB-IF specification. Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 15 bq24230 bq24232 10 μC 50 μC 20 mA/div USB100 Current Limit SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 .......................................................................................................................................... www.ti.com 100 μs/div Figure 26. USB-IF Inrush Current Test The input current limit selection is controlled by the state of the EN1 and EN2 pins as shown in Table 1. When using the resistor-programmable current limit, the input current limit is set by the value of the resistor connected from the ILIM pin to VSS and is given by the equation: IIN-MAX = KILIM/RILIM The input current limit is adjustable up to 500 mA. The valid resistor range is 3.2 kΩ to 8 kΩ. When the IN source is connected, priority is given to the system load. The DPPM and Battery Supplement modes are used to maintain the system load. Figure 27 illustrates examples of the DPPM and supplement modes. These modes are explained in detail in the following sections. Input DPM Mode, VIN-DPM The bq2423x uses the VIN-DPM mode for operation from current-limited USB ports. When EN1 and EN2 are configured for USB100 (EN2=0, EN1=0) or USB500 (EN2=0, EN2=1) modes, the input voltage is monitored. If VIN falls to VIN-DPM, the input current limit is reduced to prevent the input voltage from falling further. This prevents the bq2423x from crashing poorly designed or incorrectly configured USB sources. DPPM Mode When the sum of the charging and system load currents exceeds the preset maximum input current (programmed with EN1, EN2, and ILIM pins), the voltage at OUT decreases. Once the voltage on the OUT pin falls to VDPPM, the bq2423x enters DPPM mode. In this mode, the charging current is reduced as the OUT current goes up in order to maintain the system output. Battery termination is disabled while in DPPM mode. Battery Supplement Mode While in DPPM mode, if the charging current falls to zero and the system load current increases beyond the programmed input current limit, the voltage at OUT reduces further. When the OUT voltage drops below the battery voltage by VBSUP1, the battery supplements the system load. The battery stops supplementing the system load when the voltage on the OUT pin rises above the battery voltage by VBSUP2. During supplement mode, the battery supplement current is not regulated; however, a short-circuit protection circuit is built in. If during battery supplement mode, the voltage at OUT drops 250 mV below the BAT voltage, the OUT output is turned off if the overload exists after tDGL(SC2). The short-circuit recovery timer then starts counting. After tREC(SC2), OUT turns on and attempts to restart. If the short circuit remains, OUT is turned off and the counter restarts. Battery termination is disabled while in supplement mode. 16 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 bq24230 bq24232 www.ti.com .......................................................................................................................................... SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 IOUT 500 mA 400 mA 250 mA 0 mA IIN 400 mA 150 mA 0 mA IBAT 150 mA 0 mA -100 mA 4 .4 V 4 .3 V DPM loop active VOUT ~ 3 .6 V Supplement Mode Figure 27. bq2423x DPPM and Battery Supplement Modes (VOREG = 4.4 V, VBAT = 3.6 V, ILIM=400 mA, ICHG = 150 mA) INPUT SOURCE NOT CONNECTED When no source is connected to the IN input, OUT is powered strictly from the battery. During this mode, the current into OUT is unregulated, similar to Battery Supplement Mode; however, the short-circuit circuitry is active. If the OUT voltage falls below the BAT voltage by 250 mV for longer than tDGL(SC2), OUT is turned off. The short-circuit recovery timer then starts counting. After tREC(SC2), OUT turns on and attempts to restart. If the short-circuit remains, OUT is turned off and the counter restarts. This ON/OFF cycle continues until the overload condition is removed. BATTERY CHARGING Set CE low to initiate battery charging. First, the device checks for a short circuit on the BAT pin by sourcing IBAT(SC) to the battery and monitoring the voltage. When the BAT voltage exceeds VBAT(SC), the battery charging continues. The battery is charged in three phases: conditioning precharge, constant-current fast charge (current regulation), and a constant-voltage tapering (voltage regulation). In all charge phases, an internal control loop monitors the IC junction temperature and reduces the charge current if an internal temperature threshold is exceeded. Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 17 bq24230 bq24232 SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 .......................................................................................................................................... www.ti.com Figure 28 illustrates a normal Li-ion charge cycle using the bq2423x: PRECHARGE CC FAST CHARGE CV TAPER DONE VBAT(REG) IO(CHG) Battery Current Battery Voltage VLOWV CHG = Hi-z I(PRECHG) I(TERM) Figure 28. In the precharge phase, the battery is charged with the precharge current (IPRECHG). Once the battery voltage crosses the VLOWV threshold, the battery is charged with the fast-charge current (ICHG). As the battery voltage reaches VBAT(REG), the battery is held at a constant voltage of VBAT(REG) and the charge current tapers off as the battery approaches full charge. When the battery current reaches ITERM, the CHG pin indicates charging done by going high impedance. Note that termination detection is disabled whenever the charge rate is reduced because of the actions of the thermal loop, the DPPM loop, or the VIN(LOW) loop. The value of the fast-charge current is set by the resistor connected from the ISET pin to VSS, and is given by the equation ICHG = KISET/RISET The charge current limit is adjustable from 25 mA to 500 mA. The valid resistor range is 1.8 kΩ to 36 kΩ. Note that if ICHG is programmed as greater than the input current limit, the battery does not charge at the rate of ICHG, but at the slower rate of IIN(MAX) (minus the load current on the OUT pin, if any). In this case, the charger timers are proportionately slowed down. 18 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 bq24230 bq24232 www.ti.com .......................................................................................................................................... SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 Begin Charging Yes Yes Battery short detected ? Termination Reached BATTFET Off Wait for V BAT < VRCH No Start Precharge CHG = Low No VBAT < VRCH Yes No VBAT > VLOWV No tPRECHARGE Elapsed? Run Battery Detection Yes End Charge Flash/CHG Start Fastcharge ICHARGE set by ISET Battery Detected ? No Yes No No I BAT< ITERM tFASTCHARGE Elapsed? Yes End Charge Flash CHG Charge Done CHG = Hi-Z TD = Low (’72, ’73 Only) (’74, ’75 = YES ) No Figure 29. Battery Charging Flow Diagram CHARGE CURRENT TRANSLATOR When the charger is enabled, internal circuits generate a current proportional to the charge current at the ISET input. The current out of ISET is 1/400 (±10%) of the charge current. This current, when applied to the external charge current programming resistor, RISET, generates an analog voltage that can be monitored by an external host to calculate the current sourced from BAT. VISET=(ICHARGE / 400)×RISET Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 19 bq24230 bq24232 SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 .......................................................................................................................................... www.ti.com BATTERY DETECTION AND RECHARGE The bq2423x automatically detects if a battery is connected or removed. Once a charge cycle is complete, the battery voltage is monitored. When the battery voltage falls below VRCH, the battery detection routine is run. The detection routine first applies IBAT(DET) for tDET to see if VBAT drops below VLOWV. If not, it indicates that the battery is still connected, but has discharged. If CE is low, the charger is turned on again to top off the battery. During this recharge cycle, the CHG output remains high-impedance as recharge cycles are not indicated by the CHG pin. If the BAT voltage falls below VLOWV during the battery detection test, it indicates that the battery has been removed or the protector is open. Next, the precharge current is applied for tDET to close the protector if possible. If the battery voltage does not rise above VRCH, it indicates that the protector is closed, or a battery has been inserted, and a new charge cycle begins. If the voltage rises above VRCH, the battery is determined missing and the detection routine continues. The battery detection runs until a battery is detected. TERMINATION DISABLE (TD Input, bq24230) The bq24230 contains a TD input that allows termination to be enabled/disabled. Connect TD to a logic high to disable charge termination. When termination is disabled, the device goes through the precharge, fast-charge, and CV phases, then remains in the CV phase. During the CV phase, the charger maintains the output voltage at BAT equal to VBAT(REG), and charging current does not terminate. BAT sources currents up to ICHG or IIN-MAX, whichever is less. Battery detection is not performed. The CHG output is high impedance once the current falls below ITERM and does not go low until the input power or CE are toggled. When termination is disabled, the precharge and fast-charge safety timers are also disabled. Battery pack temperature sensing (TS pin functionality) is also disabled if the TD pin is high and the TS pin is unconnected. ADJUSTABLE TERMINATION THRESHOLD (ITERM Input, bq24232) The termination current threshold for the bq24232 is user-programmable. Set the termination current by connecting a resistor from ITERM to VSS. For USB100, mode (EN1 = EN2 = VSS), the termination current value is calculated as: ITERM = 0.01 × RITERM / RISET In the other input current limit modes (EN1 ≠ EN2), the termination current value is calculated as: ITERM = 0.03 × RITERM / RISET The termination current is programmable up to 50% of the fast-charge current. The RITERM resistor must be less than 15 kΩ. Leave ITERM unconnected to select the default internally set termination current. DYNAMIC CHARGE TIMERS (TMR Input) The bq2423x devices contain internal safety timers for the precharge and fast-charge phases to prevent potential damage to the battery and the system. The timers begin at the start of the respective charge cycles. The timer values are programmed by connecting a resistor from TMR to VSS. The resistor value is calculated using the following equation: tPRECHG = KTMR × RTMR tMAXCHG = 10 × KTMR × RTMR Leave TMR unconnected to select the internal default timers. Disable the timers by connecting TMR to VSS. Note that timers are suspended when the device is in thermal shutdown, and the timers are slowed proportionally to the charge current when the device enters thermal regulation. For the bq24230, the timers are disabled when TD is connected to a high logic level. During the fast-charge phase, several events increase the timer durations. 1. The system load current activates the DPPM loop which reduces the available charging current 2. The input current is reduced because the input voltage has fallen to VIN(LOW) 3. The device has entered thermal regulation because the IC junction temperature has exceeded TJ(REG) During each of these events, the internal timers are slowed down proportionately to the reduction in charging current. For example, if the charging current is reduced by half for two minutes, the timer clock is reduced to half the frequency and the counter counts half as fast resulting in only one minute of counted time. 20 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 bq24230 bq24232 www.ti.com .......................................................................................................................................... SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 STATUS INDICATORS (PGOOD, CHG) The bq2423x contains two open-drain outputs that signal its status. The PGOOD output signals when a valid input source is connected. PGOOD is low when (VBAT + VIN(DT)) < VIN < VOVP. When the input voltage is outside of this range, PGOOD is high impedance. The CHG output signals when a new charge cycle is initiated. After a charge cycle is initiated, CHG goes low once the battery is above the short-circuit threshold. CHG goes high impedance once the charge current falls below ITERM. CHG remains high impedance until the input power is removed and reconnected or the CE pin is toggled. It does not signal subsequent recharge cycles. PGOOD STATUS INDICATOR Input State PGOOD Output VIN < VUVLO Hi impedance VUVLO < VIN < VIN(DT) + VBAT Hi impedance VIN(DT) + VBAT < VIN < VOVP Low VIN > VOVP Hi impedance CHG STATUS INDICATOR Charge State CHG Output Charging Low (first charge cycle) Charging terminated Hi impedance until power or CE is toggled Recharging after termination Hi impedance Carging suspended by thermal loop Low (first charge cycle) Safety timers expired Flashing at 2Hz IC disabled or no valid input power Hi impedance TIMER FAULT If the precharge timer expires before the battery voltage reaches VLOWV, the bq2423x indicates a fault condition. Additionally, if the battery current does not fall to ITERM before the fast-charge timer expires, a fault is indicated. The CHG output flashes at approximately 2 Hz to indicate a fault condition. THERMAL REGULATION AND THERMAL SHUTDOWN The bq2423x contain a thermal regulation loop that monitors the die temperature. If the die temperature exceeds TJ(REG), the device automatically reduces the charging current to prevent the die temperature from increasing further. In some cases, the die temperature continues to rise despite the operation of the thermal loop, particularly under high VIN and heavy OUT system load conditions. Under these conditions, if the die temperature increases to TJ(OFF), the input FET Q1 is turned OFF. FET Q2 is turned ON to ensure that the battery still powers the load on OUT. Once the device die temperature cools by TJ(OFF-HYS), the input FET Q1 is turned on and the device returns to thermal regulation. Continuous overtemperature conditions result in a hiccup mode. Safety timers are slowed proportionally to the charge current in thermal regulation. Battery termination is disabled during thermal regulation and thermal shutdown. Note that this feature monitors the die temperature of the bq2423x. This is not synonymous with ambient temperature. Self-heating exists due to the power dissipated in the IC because of the linear nature of the battery charging algorithm and the LDO mode for OUT. A modified charge cycle with the thermal loop active is shown in Figure 30: Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 21 bq24230 bq24232 SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 .......................................................................................................................................... www.ti.com PRECHARGE THERMAL REGULATION CC FAST CHARGE CV TAPER DONE VO(REG) IO(CHG) Battery Voltage Battery Current V(LOWV) HI-z I(PRECHG) I(TERM) TJ(REG) IC Junction Temperature, TJ Figure 30. BATTERY PACK TEMPERATURE MONITORING The bq2423x features an external battery pack temperature monitoring input. The TS input connects to the NTC resistor in the battery pack to monitor battery temperature and prevent dangerous overtemperature conditions. During charging, INTC is sourced to TS and the voltage at TS is continuously monitored. If, at any time, the voltage at TS is outside of the operating range (VCOLD to VHOT), charging is suspended. The timers maintain their values but suspend counting. When the voltage measured at TS returns to within the operation window, charging is resumed and the timers continue counting. When charging is suspended due to a battery pack temperature fault, the CHG pin remains low and continues to indicate charging. For the bq24230, battery pack temperature sensing is disabled when termination is disabled (TD = High) and the voltage at TS is greater than VDIS(TS). The battery pack temperature monitoring is disabled in all devices by connecting a 10-kΩ resistor from TS to VSS. 22 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 bq24230 bq24232 www.ti.com .......................................................................................................................................... SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 The allowed temperature range for a 103AT-2 type thermistor is 0°C to 50°C. However, the user can increase the range by adding two external resistors. See Figure 31 for the circuit. The values for RT1 and RT2 are calculated using the following equations: RT1 = - 1500μA ´ (RHOT + RCOLD) ± 20 ´ 5625μA 2 ´ (RCOLD-RHOT)2 + 105μW ´ (RCOLD - RHOT) 3000μA (1) 1 V ´ (R1 + RHOT) RT2 = 250 μA ´ RT1 + 250 μA ´ RHOT - 1 V (2) RHOT and RCOLD are the thermistor resistance at the desired hot and cold temperatures, respectively. Note that the temperature window cannot be tightened more than using on the thermistor connected to TS, it can only be extended. INTC bq2407x TS RT1 + PACK+ TEMP VCOLD RT2 + VHOT PACK- Figure 31. Extended TS Temperature Thresholds Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 23 bq24230 bq24232 SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 .......................................................................................................................................... www.ti.com APPLICATIONS INFORMATION bq24232 CHARGER DESIGN EXAMPLE See Figure 18 for the Design Example Schematic. Requirements • • • • • • Supply voltage = 5 V Fast-charge current of approximately 200 mA; ISET - pin 16 Input Current Limit =500 mA; ILIM - pin 12 Termination Current = 25 mA - pin 15 Safety timer duration, Fast charge = 6.25 hours; TMR – pin 14 TS – Battery Temperature Sense = 10 kΩ NTC (103AT-2) Calculations Program the Fast-Charge Current (ISET): RISET = KISET / ICHG KISET = 870 AΩ from the electrical characteristics table. RISET = 870 AΩ/0.2 A = 4.35kΩ Select the closest standard value, which for this case is 4.32 kΩ. Connect this resistor between ISET (pin 16) and VSS. Program the Input Current Limit (ILIM) RILIM = KILIM / II_MAX KILIM = 1470 AΩ from the electrical characteristics table. RISET = 1470 AΩ / 0.5 A = 2.94 kΩ Select the closest standard value, which for this case is 2.94 kΩ. Connect this resistor between ILIM (pin 12) and VSS. Program the Termination Current Threshold (ITERM) RITERM = RISET × ITERM / KITERM KITERM = 0.03 A from electrical characteristics table RITERM = 4.32 kΩ × 0.025 A/0.03 A = 3.6 kΩ Select the closest standard value, which for this case is 3.57 kΩ. Connect this resistor between ITERM (pin 15) and VSS Program 6.25-Hour Fast-Charge Safety Timer (TMR) RTMR = tMAXCHG / (10 × KTMR) KTMR = 40 s/kΩ from the electrical characteristics table. RTMR = (6.25 hr × 3600 s/hr) / (10 × 40 s/kΩ) = 56.25 kΩ Select the closest standard value, which for this case is 56.2 kΩ. Connect this resistor between TMR (pin 2) and VSS. TS Function Use a 10-kΩ NTC thermistor in the battery pack (103AT). To disable the temperature sense function, use a fixed 10-kΩ resistor between the TS (pin 1) and VSS. Pay close attention to the linearity of the chosen NTC so that it provides the desired hot and cold turnoff thresholds. 24 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 bq24230 bq24232 www.ti.com .......................................................................................................................................... SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 CHG and PGOOD LED Status: connect a 1.5-kΩ resistor in series with a LED between OUT and CHG and OUT and PGOOD. Processor Monitoring Status: connect a pullup resistor (approximately 100 kΩ) between the processor’s power rail and CHG and PGOOD. SELECTING IN, OUT, AND BAT PIN CAPACITORS In most applications, all that is needed is a high-frequency decoupling capacitor (ceramic) on the power pin, input, output, and battery pins. Using the values shown on the application diagram is recommended. After evaluation of these voltage signals with real system operational conditions, the user can determine if capacitance values can be adjusted toward the minimum recommended values (dc load application) or higher values for fast, high-amplitude, pulsed load applications. ???Note if designed high input voltage sources (bad adapters or wrong adapters), the capacitor needs to be rated appropriately. Ceramic capacitors are tested to 2x their rated values so a 16-V capacitor may be adequate for a 30-V transient (verify tested rating with capacitor manufacturer). THERMAL PACKAGE The bq2423x is packaged in a thermally enhanced MLP package. The package includes a thermal pad to provide an effective thermal contact between the IC and the printed-circuit board (PCB). The power pad must be directly connected to the Vss pin. Full PCB design guidelines for this package are provided in the application report entitled: QFN/SON PCB Attachment (SLUA271). The most common measure of package thermal performance is thermal impedance (θJA ) measured (or modeled) from the chip junction to the air surrounding the package surface (ambient). The mathematical expression for θJA is: θJA = (TJ - T) / P Where: TJ = chip junction temperature T = ambient temperature P = device power dissipation Factors that can greatly influence the measurement and calculation of θJA include: 1. 2. 3. 4. 5. Whether the device is board mounted Trace size, composition, thickness, and geometry Orientation of the device (horizontal or vertical) Volume of the ambient air surrounding the device under test and airflow Whether other surfaces are in close proximity to the device being tested Due to the charge profile of Li-ion batteries, the maximum power dissipation is typically seen at the beginning of the charge cycle when the battery voltage is at its lowest. Typically, after fast charge begins, the pack voltage increases to ~3.4 V within the first 2 minutes. The thermal time constant of the assembly typically takes a few minutes to heat up so when doing maximum power dissipation calculations, 3.4 V is a good minimum voltage to use. This is easy to verify, with the system and a fully discharged battery, by plotting temperature on the bottom of the PCB under the IC (pad must have multiple vias), the charge current and the battery voltage as a function of time. The fast-charge current starts to taper off if the part goes into thermal regulation. The device power dissipation, P, is a function of the charge rate and the voltage drop across the internal PowerFET. It can be calculated from the following equation when a battery pack is being charged : P = [V(IN) – V(OUT)] × I(OUT) + [V(OUT) – V(BAT)] × I(BAT) The thermal loop feature reduces the charge current to limit excessive IC junction temperature. It is recommended that the design not run in thermal regulation for typical operating conditions (nominal input voltage and nominal ambient temperatures) and use the feature for nontypical situations such as hot environments or higher than normal input source voltage. With that said, the IC still performs as described, if the thermal loop is always active. Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 25 bq24230 bq24232 SLUS821A – OCTOBER 2008 – REVISED DECEMBER 2008 .......................................................................................................................................... www.ti.com Half-Wave Adapters Some low-cost adapters implement a half rectifier topology, which causes the adapter output voltage to fall below the battery voltage during part of the cycle. To enable operation with low-cost adapters under those conditions, the bq2407x family keeps the charger on for at least 20 ms (typical) after the input power puts the part in sleep mode. This feature enables use of external low-cost adapters using 50-Hz networks. Sleep Mode After entering sleep mode for >20 ms, the internal FET connection between the IN and OUT pin is disabled and pulling the input to ground does not discharge the battery, other than the leakage on the BAT pin. If the user has a full 1000-mAHr battery and the leakage is 10 µA, then it takes 1000 mAHr/10 µA = 100000 hours (11.4 years) to discharge the battery. The battery’s self-discharge is typically 5 times higher. Layout Tips • • • • 26 To obtain optimal performance, the decoupling capacitor from IN to GND (thermal pad) and the output filter capacitors from OUT to GND (thermal pad) must be placed as close as possible to the bq2423x, with short trace runs to both IN, OUT, and GND (thermal pad). All low-current GND connections must be kept separate from the high-current charge or discharge paths from the battery. Use a single-point ground technique incorporating both the small signal ground path and the power ground path. The high current charge paths into the IN pin and from the OUT pin must be sized appropriately for the maximum charge current in order to avoid voltage drops in these traces. The bq2423x family is packaged in a thermally enhanced MLP package. The package includes a thermal pad to provide an effective thermal contact between the IC and the printed-circuit board (PCB); this thermal pad is also the main ground connection for the device. Connect the thermal pad to the PCB ground connection. Full PCB design guidelines for this package are provided in the application report entitled: QFN/SON PCB Attachment (SLUA271). Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq24230 bq24232 PACKAGE OPTION ADDENDUM www.ti.com 18-Nov-2008 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty BQ24230RGTR ACTIVE QFN RGT 16 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR BQ24230RGTRG4 ACTIVE QFN RGT 16 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR BQ24230RGTT ACTIVE QFN RGT 16 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR BQ24230RGTTG4 ACTIVE QFN RGT 16 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR BQ24232RGTR ACTIVE QFN RGT 16 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR BQ24232RGTRG4 ACTIVE QFN RGT 16 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR BQ24232RGTT ACTIVE QFN RGT 16 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR BQ24232RGTTG4 ACTIVE QFN RGT 16 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR 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. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 12-Dec-2008 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing BQ24230RGTR QFN RGT 16 SPQ Reel Reel Diameter Width (mm) W1 (mm) A0 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 3000 330.0 12.4 3.3 3.3 1.1 8.0 12.0 Q2 BQ24230RGTT QFN RGT 16 250 180.0 12.4 3.3 3.3 1.1 8.0 12.0 Q2 BQ24232RGTR QFN RGT 16 3000 330.0 12.4 3.3 3.3 1.1 8.0 12.0 Q2 BQ24232RGTT QFN RGT 16 250 180.0 12.4 3.3 3.3 1.1 8.0 12.0 Q2 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 12-Dec-2008 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) BQ24230RGTR QFN RGT 16 3000 346.0 346.0 29.0 BQ24230RGTT QFN RGT 16 250 190.5 212.7 31.8 BQ24232RGTR QFN RGT 16 3000 346.0 346.0 29.0 BQ24232RGTT QFN RGT 16 250 190.5 212.7 31.8 Pack Materials-Page 2 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. 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