FAN54015 USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Features Description Fully Integrated, High-Efficiency Charger for Single-Cell Li-Ion and Li-Polymer Battery Packs Faster Charging than Linear The FAN54015 combines a highly integrated switch-mode charger, to minimize single-cell Lithium-ion (Li-ion) charging time from a USB power source, and a boost regulator to power a USB peripheral from the battery. 5% Input Current Regulation Accuracy Charge Voltage Accuracy: 0.5% at 25°C 1% from 0 to 125°C 5% Charge Current Regulation Accuracy 20 V Absolute Maximum Input Voltage 6 V Maximum Input Operating Voltage 1.45 A Maximum Charge Rate Programmable through High-Speed I2C Interface (3.4 Mb/s) with Fast Mode Plus Compatibility – Input Current – – – Fast-Charge / Termination Current Charger Voltage Termination Enable 3 MHz Synchronous Buck PWM Controller with Wide Duty Cycle Range Small Footprint 1 H External Inductor Safety Timer with Reset Control 1.8 V Regulated Output from VBUS for Auxiliary Circuits Dynamic Input Voltage Control Low Reverse Leakage to Prevent Battery Drain to VBUS 5 V, 500 mA Boost Mode for USB OTG for 3.0 V to 4.5 V Battery Input Available in a 1.96 x 1.87 mm, 20-bump, 0.4 mm Pitch WLCSP Package Applications Cell Phones, Smart Phones, PDAs Tablet, Portable Media Players The charging parameters and operating modes are programmable through an I2C Interface that operates up to 3.4 Mbps. The charger and boost regulator circuits switch at 3 MHz to minimize the size of external passive components. The FAN54015 provides battery charging in three phases: conditioning, constant current and constant voltage. To ensure USB compliance and minimize charging time, the input current limit can be changed through the I2C by the host processor. Charge termination is determined by a programmable minimum current level. A safety timer with reset control provides a safety backup for the I2C host. Charge status is reported to the host through the I2C port. The integrated circuit (IC) automatically restarts the charge cycle when the battery falls below an internal threshold. If the input source is removed, the IC enters a high-impedance mode, preventing leakage from the battery to the input. Charge current is reduced when the die temperature reaches 120°C, protecting the device and PCB from damage. The FAN54015 can operate as a boost regulator on command from the system. The boost regulator includes a soft-start that limits inrush current from the battery and uses the same external components used for charging the battery. L1 SW VBUS CBUS 1H 1F COUT 0.1F PGND PMID CMID CSIN 4.7F SDA SCL RSENSE FAN54015 68m VBAT DISABLE OTG/USB# STAT VREG CREG + Battery CBAT SYSTEM LOAD 10F 1F Gaming Device, Digital Cameras Figure 1. Typical Application All trademarks are the property of their respective owners. © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator October 2013 Part Number Temperature Range Package -40 to 85°C 20-Bump, Wafer-Level Chip-Scale Package (WLCSP), 0.4 mm Pitch, Estimated Size: 1.96 x 1.87 mm FAN54015UCX FAN54015BUCX(1) Packing Method PN Bits: IC_INFO[4:2] Tape and Reel 101 Note: 1. FAN54015BUCX includes backside lamination. Table 1. Feature Summary Part Number Slave Address Automatic Charge Special Charger(2) Safety Limits Battery Absent Behavior E2 Pin VREG (E3 Pin) FAN54015UCX 1101010 Yes Yes Yes ON DISABLE 1.8 V Note: 2. A “special charger” is a current-limited charger that is not a USB compliant source. Block Diagram VREG 1.8V / PMID REG CREG PMID 1F PMID Q1 Q3 CMID Q1A VBUS CBUS CHARGE PUMP 1F 4.7F Q1B SW VBUS OVP PWM MODULATOR I_IN CONTROL Q2 L1 1H COUT RSENSE 0.1F DAC VCC PGND VREF CSIN + Battery VBAT SDA SCL DISABLE OTG/USB# PMID I2C INTERFACE STAT 30mA CBAT SYSTEM LOAD OSC LOGIC AND CONTROL PMID Greater than VBAT Less than VBAT Q1A ON OFF Q1B OFF ON Figure 2. IC and System Block Diagram Table 2. Recommended External Components Component Description Vendor 1 H ±20%, 1.6 A, DCR=55 m, 2520 Murata: LQM2HPN1R0 1 H ±30%, 1.4 A, DCR=85 m, 2016 Murata: LQM2MPN1R0 CBAT 10 F, 20%, 6.3 V, X5R, 0603 CMID CBUS L1 Parameter Typ. Unit L 1.0 H Murata: GRM188R60J106M TDK: C1608X5R0J106M C 10 F 4.7 F, 10%, 6.3 V, X5R, 0603 Murata: GRM188R60J475K TDK: C1608X5R0J475K C(3) 4.7 F 1.0 F, 10%, 25 V, X5R, 0603 Murata GRM188R61E105K TDK:C1608X5R1E105M C 1.0 F Note: 3. A 6.3 V rating is sufficient for CMID because PMID is protected from over-voltage surges on VBUS by Q3 (Figure 2). © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 2 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Ordering Information A1 A2 A3 A4 A4 A3 A2 A1 B1 B2 B3 B4 B4 B3 B2 B1 C1 C2 C3 C4 C4 C3 C2 C1 D1 D2 D3 D4 D4 D3 D2 D1 E1 E2 E3 E4 E4 E3 E2 E1 Top View Bottom View Figure 3. WLCSP-20 Pin Assignments Pin Definitions Pin # Name Description A1, A2 VBUS Charger Input Voltage and USB-OTG output voltage. Bypass with a 1 F capacitor to PGND. A3 NC No Connect. No external connection is made between this pin and the IC’s internal circuitry. A4 SCL I2C Interface Serial Clock. This pin should not be left floating. B1-B3 PMID Power Input Voltage. Power input to the charger regulator, bypass point for the input current sense, and high-voltage input switch. Bypass with a minimum of 4.7 F, 6.3 V capacitor to PGND. B4 SDA I2C Interface Serial Data. This pin should not be left floating. C1-C3 SW Switching Node. Connect to output inductor. C4 STAT Status. Open-drain output indicating charge status. The IC pulls this pin LOW when charging. D1-D3 PGND Power Ground. Power return for gate drive and power transistors. The connection from this pin to the bottom of CMID should be as short as possible. D4 OTG On-The-Go. Enables boost regulator in conjunction with OTG_EN and OTG_PL bits (see Table 16). On VBUS Power-On Reset (POR), this pin sets the input current limit for t15MIN charging. E1 CSIN Current-Sense Input. Connect to the sense resistor in series with the battery. The IC uses this node to sense current into the battery. Bypass this pin with a 0.1 F capacitor to PGND. E2 DISABLE E3 VREG Regulator Output. Connect to a 1 F capacitor to PGND. This pin can supply up to 2mA of DC load current. The output voltage is PMID, which is limited to 1.8 V. E4 VBAT Battery Voltage. Connect to the positive (+) terminal of the battery pack. Bypass with a 0.1 F capacitor to PGND if the battery is connected through long leads. Charge Disable. If this pin is HIGH, charging is disabled. When LOW, charging is controlled by the I2C registers. When this pin is HIGH, the 15-minute timer is reset. This pin does not affect the 32-second timer. © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 3 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Pin Configuration Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only. Symbol Parameter VBUS VBUS Voltage VSTAT STAT Voltage VI VO Min. Continuous –1.4 Pulsed, 100 ms Maximum Non-Repetitive –2.0 –0.3 PMID Voltage Max. Unit 20.0 V 16.0 V 7.0 V SW, CSIN, VBAT, DISABLE Voltage –0.3 7.0 Voltage on Other Pins –0.3 6.5(4) V 4 V/s dVBUS dt Maximum VBUS Slope above 5.5 V when Boost or Charger are Active ESD Electrostatic Discharge Protection Level TJ Junction Temperature –40 +150 °C TSTG Storage Temperature –65 +150 °C +260 °C TL Human Body Model per JESD22-A114 2000 Charged Device Model per JESD22-C101 500 Lead Soldering Temperature, 10 Seconds V Note: 4. Lesser of 6.5 V or VI + 0.3 V. Recommended Operating Conditions The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not recommend exceeding them or designing to absolute maximum ratings. Symbol VBUS VBAT(MAX) dVBUS dt Parameter Min. Supply Voltage 4 Maximum Battery Voltage when Boost enabled Negative VBUS Slew Rate during VBUS Short Circuit, CMID < 4.7 F (see VBUS Short While Charging) Max. Unit 6 V 4.5 V TA < 60°C 4 TA > 60°C 2 V/s TA Ambient Temperature –30 +85 °C TJ Junction Temperature (see Thermal Regulation and Protection section) –30 +120 °C Thermal Properties Junction-to-ambient thermal resistance is a function of application and board layout. This data is measured with four-layer 2s2p boards in accordance to JEDEC standard JESD51. Special attention must be paid not to exceed junction temperature TJ(max) at a given ambient temperature TA. For measured data, see Table 11. Symbol Parameter Typical Unit JA Junction-to-Ambient Thermal Resistance 60 °C/W JB Junction-to-PCB Thermal Resistance 20 °C/W © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 4 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Absolute Maximum Ratings Unless otherwise specified: according to the circuit of Figure 1; recommended operating temperature range for TJ and TA; VBUS=5.0 V; HZ_MODE; OPA_MODE=0; (Charge Mode); SCL, SDA, OTG=0 or 1.8 V; and typical values are for TJ=25°C. Symbol Parameter Conditions Min. Typ. Max. Unit Power Supplies IVBUS VBUS Current ILKG VBAT to VBUS Leakage Current IBAT Battery Discharge Current in HighImpedance Mode VBUS > VBUS(min), PWM Switching 10 mA VBUS > VBUS(min); PWM Enabled, Not Switching (Battery OVP Condition); I_IN Setting=100 mA 2.5 mA 0°C < TJ < 85°C, HZ_MODE=1 VBAT < VLOWV, 32S Mode 63 90 A 0°C < TJ < 85°C, HZ_MODE=1, VBAT=4.2 V, VBUS=0 V 0.2 5.0 A 0°C < TJ < 85°C, HZ_MODE=1, VBAT=4.2 V 20 DISABLE=1, 0°C < TJ < 85°C, VBAT=4.2 V 10 A Charger Voltage Regulation Charge Voltage Range VOREG Charge Voltage Accuracy 3.5 4.4 –0.5% +0.5% TJ=0 to 125°C –1% +1% VLOWV < VBAT < VOREG, RSENSE=68 m 550 1450 mA 20 mV ≤ VIREG ≤ 40 mV 92 97 102 % VIREG > 40 mV 94 97 100 % TA=25°C V Charging Current Regulation Output Charge Current Range IOCHRG Charge Current Accuracy Across RSENSE Weak Battery Detection VLOWV Weak Battery Threshold Range 3.4 3.7 V Weak Battery Threshold Accuracy –5 +5 % Weak Battery Deglitch Time Rising Voltage 30 ms Logic Levels: DISABLE, SDA, SCL, OTG VIH High-Level Input Voltage VIL Low-Level Input Voltage IIN Input Bias Current 1.05 Input Tied to GND or VIN V 0.01 0.4 V 1.00 A mA Charge Termination Detection Termination Current Range I(TERM) Termination Current Accuracy Termination Current Deglitch Time VBAT > VOREG – VRCH, RSENSE=68 m 50 400 [VCSIN – VBAT ] from 3 mV to 20 mV –25 +25 [VCSIN – VBAT ] from 20 mV to 40 mV –5 +5 2 mV Overdrive 30 % ms 1.8V Linear Regulator VREG 1.8V Regulator Output IREG from 0 to 2 mA 1.7 1.8 1.9 V Input Power Source Detection VIN(MIN)1 VBUS Input Voltage Rising To Initiate and Pass VBUS Validation 4.29 4.42 V VIN(MIN)2 Minimum VBUS During Charge During Charging 3.71 3.94 V tVBUS_VALID VBUS Validation Time 30 ms Continued on the following page… © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 5 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Electrical Specifications Unless otherwise specified: according to the circuit of Figure 1; recommended operating temperature range for TJ and TA; VBUS=5.0 V; HZ_MODE; OPA_MODE=0; (Charge Mode); SCL, SDA, OTG=0 or 1.8 V; and typical values are for TJ=25°C. Symbol Parameter Conditions Min. Typ. Max. Unit +3 % Special Charger (VBUS) VSP –3 Special Charger Setpoint Accuracy Input Current Limit IINLIM Input Current Limit Threshold IIN Set to 100 mA 88 93 98 IIN Set to 500 mA 450 475 500 mA VREF Bias Generator VREF Bias Regulator Voltage VBUS > VIN(MIN) or VBAT > VBAT(MIN) 6.5 Short-Circuit Current Limit 20 V mA Battery Recharge Threshold Recharge Threshold Below V(OREG) Deglitch Time VBAT Falling Below VRCH Threshold VSTAT(OL) STAT Output Low ISTAT=10 mA ISTAT(OH) STAT High Leakage Current VSTAT=5 V VRCH 100 120 150 130 mV ms STAT Output 0.4 V 1 A Battery Detection IDETECT Battery Detection Current before Charge Done (Sink Current)(5) tDETECT Battery Detection Time Begins after Termination Detected and VBAT < VOREG –VRCH –0.80 mA 262 ms Sleep Comparator VSLP tSLP_EXIT Sleep-Mode Entry Threshold, VBUS – VBAT 2.3 V < VBAT < VOREG, VBUS Falling Deglitch Time for VBUS Rising Above VBAT by VSLP Rising Voltage 30 IIN(LIMIT)=500 mA 0 0.04 0.10 V ms Power Switches (see Figure 2) Q3 On Resistance (VBUS to PMID) RDS(ON) 180 250 Q1 On Resistance (PMID to SW) 130 225 Q2 On Resistance (SW to GND) 150 225 mΩ Charger PWM Modulator fSW Oscillator Frequency DMAX Maximum Duty Cycle DMIN Minimum Duty Cycle ISYNC Synchronous to Non-Synchronous Current Cut-Off Threshold(6) 2.7 Low-Side MOSFET (Q2) Cycle-byCycle Current Limit 3.0 3.3 MHz 100 % 0 % 140 mA Boost Mode Operation (OPA_MODE=1, HZ_MODE=0) VBOOST Boost Output Voltage at VBUS IBAT(BOOST) Boost Mode Quiescent Current ILIMPK(BST) Q2 Peak Current Limit UVLOBST Minimum Battery Voltage for Boost Operation 2.5 V < VBAT < 4.5 V, ILOAD from 0 to 200 mA 4.80 5.07 5.17 3.0 V < VBAT < 4.5 V, ILOAD from 0 to 500 mA 4.77 5.07 5.17 140 300 A 1590 1908 mA V PFM Mode, VBAT=3.6 V, IOUT=0 1272 While Boost Active 2.42 To Start Boost Regulator 2.58 2.70 V Continued on the following page… © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 6 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Electrical Specifications Unless otherwise specified: according to the circuit of Figure 1; recommended operating temperature range for TJ and TA; VBUS=5.0 V; HZ_MODE; OPA_MODE=0; (Charge Mode); SCL, SDA, OTG=0 or 1.8 V; and typical values are for TJ=25°C. Symbol Parameter Conditions Min. Typ. Max. Unit VBUS Load Resistance RVBUS VBUS to PGND Resistance Normal Operation 1500 k Charger Validation 100 Protection and Timers VBUSOVP ILIMPK(CHG) VSHORT ISHORT TSHUTDWN VBUS Over-Voltage Shutdown VBUS Rising Hysteresis VBUS Falling 100 mV Q1 Cycle-by-Cycle Peak Current Limit Charge Mode 2.3 A Battery Short-Circuit Threshold VBAT Rising Hysteresis VBAT Falling Linear Charging Current VBAT < VSHORT Thermal Shutdown Threshold Hysteresis (7) (7) TCF Thermal Regulation Threshold(7) tINT Detection Interval t32S 32-Second Timer(8) 6.09 1.95 6.29 2.00 6.49 2.05 100 20 30 V V mV 40 mA TJ Rising 145 TJ Falling 10 Charge Current Reduction Begins 120 °C 2.1 s °C Charger Enabled 20.5 25.2 28.0 Charger Disabled 18.0 25.2 34.0 13.5 15.0 min 25 % t15MIN 15-Minute Timer 15-Minute Mode 12.0 ∆tLF Low-Frequency Timer Accuracy Charger Inactive –25 s Notes: 5. Negative current is current flowing from the battery to VBUS (discharging the battery). 6. Q2 always turns on for 60 ns, then turns off if current is below ISYNC. 7. Guaranteed by design; not tested in production. 8. This tolerance (%) applies to all timers on the IC, including soft-start and deglitching timers. © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 7 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Electrical Specifications Guaranteed by design. Symbol Parameter Conditions Min. Typ. Standard Mode fSCL tBUF SCL Clock Frequency Bus-Free Time between STOP and START Conditions tHD;STA tLOW SCL LOW Period Fast Mode 400 High-Speed Mode, CB < 100 pF 3400 High-Speed Mode, CB < 400 pF 1700 Standard Mode 4.7 Fast Mode 1.3 tSU;STA tSU;DAT SCL HIGH Period Repeated START Setup Time Data Setup Time tRCL tFCL tRDA tRCL1 Data Hold Time SCL Rise Time SCL Fall Time SDA Rise Time Rise Time of SCL after a Repeated START Condition and after ACK Bit s s Fast Mode 600 ns High-Speed Mode 160 ns Standard Mode 4.7 s Fast Mode 1.3 s High-Speed Mode, CB < 100 pF 160 ns High-Speed Mode, CB < 400 pF 320 ns 4 s Fast Mode 600 ns High-Speed Mode, CB < 100 pF 60 ns High-Speed Mode, CB < 400 pF 120 ns Standard Mode 4.7 s Fast Mode 600 ns High-Speed Mode 160 ns Standard Mode 250 Fast Mode 100 High-Speed Mode tHD;DAT kHz 4 Standard Mode tHIGH Unit 100 Standard Mode START or Repeated START Hold Time Max. ns 10 Standard Mode 0 3.45 s Fast Mode 0 900 ns High-Speed Mode, CB < 100 pF 0 70 ns ns High-Speed Mode, CB < 400 pF 0 150 Standard Mode 20+0.1CB 1000 Fast Mode 20+0.1CB 300 High-Speed Mode, CB < 100 pF 10 80 High-Speed Mode, CB < 400 pF 20 160 Standard Mode 20+0.1CB 300 Fast Mode 20+0.1CB 300 High-Speed Mode, CB < 100 pF 10 40 High-Speed Mode, CB < 400 pF 20 80 Standard Mode 20+0.1CB 1000 Fast Mode 20+0.1CB 300 High-Speed Mode, CB < 100 pF 10 80 High-Speed Mode, CB < 400 pF 20 160 ns ns ns Continued on the following page… © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 8 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator I2C Timing Specifications Guaranteed by design. Symbol Parameter tFDA Conditions SDA Fall Time tSU;STO Stop Condition Setup Time CB Min. Typ. Max. Standard Mode 20+0.1CB 300 Fast Mode Unit 20+0.1CB 300 High-Speed Mode, CB < 100 pF 10 80 High-Speed Mode, CB < 400 pF 20 160 Standard Mode 4 s Fast Mode 600 ns High-Speed Mode 160 Capacitive Load for SDA, SCL ns ns 400 pF Timing Diagrams tF tSU;STA tBUF SDA tR TSU;DAT tHD;STO tHIGH SCL tLOW tHD;STA tHD;DAT tHD;STA REPEATED START START STOP START Figure 4. I2C Interface Timing for Fast and Slow Modes tFDA tRDA REPEATED START tSU;DAT STOP SDAH tSU;STA tRCL1 tFCL tRCL tSU;STO tHIGH SCLH tLOW tHD;STA tHD;DAT REPEATED START note A = MCS Current Source Pull-up = RP Resistor Pull-up Note A: First rising edge of SCLH after Repeated Start and after each ACK bit. Figure 5. I2C Interface Timing for High-Speed Mode © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 9 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator I2C Timing Specifications 180 900 160 800 140 700 Battery Charge Current (mA) Battery Charge Current (mA) Unless otherwise specified, circuit of Figure 1, VOREG=4.2 V, VBUS=5.0 V, and TA=25°C. 120 100 80 60 40 5.5VBUS 600 500 400 300 200 5.0VBUS 20 5.5VBUS 5.0VBUS 100 4.5VBUS 4.5VBUS - 2.5 3 3.5 4 4.5 2.5 3 Battery Voltage, VBAT (V) 3.5 4 4.5 Battery Voltage, VBAT (V) Figure 6. Battery Charge Current vs. VBUS with IINLIM=100 mA Figure 7. Battery Charge Current vs. VBUS with IINLIM=500 mA 94% 97% 4.20VBAT, 4.5VBUS 4.20VBAT, 5.0VBUS 3.54VBAT, 5.0VBUS 94% 92% Efficiency Efficiency 3.54VBAT, 4.5VBUS 91% 88% 85% 90% 88% 86% 4.5VBUS 5.0VBUS 5.5VBUS 82% 100 84% 300 500 700 900 1100 1300 1500 2.5 Battery Charge Current (mA) 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 Battery Voltage, VBAT (V) Figure 8. Charger Efficiency, No IINLIM, IOCHARGE=1450 mA Figure 9. Charger Efficiency vs. VBUS, IINLIM=500 mA Figure 10. Auto-Charge Startup at VBUS Plug-in, IINLIM=100 mA, OTG=1, VBAT=3.4 V © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 2.7 Figure 11. Auto-Charge Startup at VBUS Plug-in, IINLIM=500 mA, OTG=1, VBAT=3.4 V www.fairchildsemi.com 10 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Charge Mode Typical Characteristics Unless otherwise specified, circuit of Figure 1, VOREG=4.2 V, VBUS=5.0 V, and TA=25°C. Figure 12. AutoCharge Startup with 300mA Limited Charger / Adaptor, IINLIM=500 mA, OTG=1, VBAT=3.4 V Figure 13. Charger Startup with HZ_MODE Bit Reset, IINLIM=500 mA, IOCHARGE=1050 mA, OREG=4.2 V, VBAT=3.6 V Figure 14. Battery Removal / Insertion During Charging, VBAT=3.9 V, IOCHARGE=1050 mA, No IINLIM, TE=0 Figure 15. Battery Removal / Insertion During Charging, VBAT=3.9 V, IOCHARGE=1050 mA, No IINLIM, TE=1 © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 11 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Charge Mode Typical Characteristics Unless otherwise specified, circuit of Figure 1, VOREG=4.2 V, VBUS=5.0 V, and TA=25°C. 1.82 200 -30C +25C 1.80 VREG (V) High-Z Mode Current (A) 1.81 150 +85C 100 1.79 -10C, 5.0VBUS 50 1.78 +25C, 5.0VBUS +85C, 5.0VBUS 0 1.77 4.0 4.5 5.0 5.5 6.0 0 Input Voltage, VBUS (V) 1 2 3 4 5 1.8V Regulator Load Current (mA) Figure 16. VBUS Current in High-Impedance Mode with Battery Open Figure 17. VREG 1.8 V Output Regulation Figure 18. No Battery, VBUS at Power Up © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 12 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Charge Mode Typical Characteristics 100 100 95 95 90 90 Efficiency (%) Efficiency (%) Unless otherwise specified, using circuit of Figure 1, VBAT=3.6 V, TA=25°C. 85 3.0 VBAT 80 85 -10C, 3.6VBAT 80 +25C, 3.6VBAT 3.6 VBAT +85C, 3.6VBAT 4.2 VBAT 75 75 0 100 200 300 400 0 500 100 200 300 400 500 VBUS Load Current (mA) VBUS Load Current (mA) Figure 19. Efficiency vs. VBAT Figure 20. Efficiency Over Temperature 5.10 5.10 3.0 VBAT -10C, 3.6VBAT 3.6 VBAT 5.05 +25C, 3.6VBAT 5.05 4.2 VBAT +85C, 3.6VBAT 5.00 VBUS (V) VBUS (V) 5.00 4.95 4.95 4.90 4.90 4.85 4.85 4.80 4.80 0 100 200 300 400 500 0 100 VBUS Load Current (mA) 200 300 400 500 VBUS Load Current (mA) Figure 21. Output Regulation vs. VBAT Figure 22. Output Regulation Over Temperature 250 20 -30C Quiescent Current (µA) High-Z Mode Current (µA) +25C 200 +85C 150 100 15 10 -30C 5 +25C +85C 50 0 2 2.5 3 3.5 4 4.5 5 2 Battery Voltage, VBAT (V) 3 3.5 4 4.5 5 Battery Voltage, VBAT (V) Figure 23. Quiescent Current © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 2.5 Figure 24. High-Impedance Mode Battery Current www.fairchildsemi.com 13 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Boost Mode Typical Characteristics Unless otherwise specified, using circuit of Figure 1, VBAT=3.6 V, TA=25°C. Figure 25. Boost PWM Waveform Figure 26. Boost PFM Waveform 30 30 2.7 VBAT -30C, 3.6VBAT 3.6 VBAT 25 +25C, 3.6VBAT 25 4.2 VBAT +85C, 3.6VBAT VBUS Ripple (mVpp) VBUS Ripple (mVpp) 4.5 VBAT 20 15 10 5 20 15 10 5 0 0 0 100 200 300 400 500 0 VBUS Load Current (mA) 200 300 400 500 VBUS Load Current (mA) Figure 27. Output Ripple vs. VBAT © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 100 Figure 28. Output Ripple vs. Temperature www.fairchildsemi.com 14 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Boost Mode Typical Characteristics Unless otherwise specified, using circuit of Figure 1, VBAT=3.6 V, TA=25°C. VBUS IL IBAT Figure 29. Startup, 3.6 VBAT, 44 Load, Additional 10 µF, X5R Across VBUS Figure 30. VBUS Fault Response, 3.6 VBAT Figure 31. Load Transient, 5-155-5 mA, tR=tF=100 ns Figure 32. Load Transient, 5-255-5 mA, tR=tF=100 ns © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 15 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Boost Mode Typical Characteristics When charging batteries with a current-limited input source, such as USB, a switching charger’s high efficiency over a wide range of output voltages minimizes charging time. The FAN54015 is designed to work with a current-limited input source at VBUS. During the current regulation phase of charging, IINLIM or the programmed charging current limits the amount of current available to charge the battery and power the system. The effect of I INLIM on ICHARGE can be seen in Figure 34. FAN54015 combines a highly integrated synchronous buck regulator for charging with a synchronous boost regulator, which can supply 5 V to USB On-The-Go (OTG) peripherals. The regulator employs synchronous rectification for both the charger and boost regulators to maintain high efficiency over a wide range of battery voltages and charge states. VOREG VOREG ICHARGE VB The FAN54015 has three operating modes: 1. Charge Mode: Charges a single-cell Li-ion or Li-polymer battery. 2. Boost Mode: Provides 5 V power to USB-OTG with an integrated synchronous rectification boost regulator using the battery as input. 3. AT ITERM VSHORT VSHORT ISHORT ISHORT High-Impedance Mode: Both the boost and charging circuits are OFF in this mode. Current flow from VBUS to the battery or from the battery to VBUS is blocked in this mode. This mode consumes very little current from VBUS or the battery. PRECHARGE CONSTANT CURRENT (CC) CONSTANT VOLTAGE (CV) Figure 33. Charge Curve, ICHARGE Not Limited by IINLIM Note: Default settings are denoted by bold typeface. VOREG Charge Mode In Charge Mode, FAN54015 employs four regulation loops: 1. Input Current: Limits the amount of current drawn from VBUS. This current is sensed internally and can be programmed through the I2C interface. 2. Charging Current: Limits the maximum charging current. This current is sensed using an external RSENSE resistor. 3. T V BA Temperature: If the IC’s junction temperature reaches 120°C, charge current is reduced until the IC’s temperature stabilizes at 120°C. 5. An additional loop limits the amount of drop on VBUS to a programmable voltage (VSP) to accommodate “special chargers” that limit current to a lower current than might be available from a “normal” USB wall charger. ISHORT PRECHARGE CURRENT REGULATION VOLTAGE REGULATION Figure 34. Charge Curve, IINLIM Limits ICHARGE Assuming that VOREG is programmed to the cell’s fully charged “float” voltage, the current that the battery accepts with the PWM regulator limiting its output (sensed at VBAT) to VOREG declines, and the charger enters the voltage regulation phase of charging. When the current declines to the programmed ITERM value, the charge cycle is complete. Charge current termination can be disabled by resetting the TE bit (REG1[3]). Battery Charging Curve The charger output or “float” voltage can be programmed by the OREG bits from 3.5 V to 4.44 V in 2 0mV increments, as shown in Table 3. If the battery voltage is below VSHORT, a linear current source pre-charges the battery until VBAT reaches VSHORT. The PWM charging circuit is then started and the battery is charged with a constant current if sufficient input power is available. The current slew rate is limited to prevent overshoot. © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 HA R GE ITERM VSHORT Charge Voltage: The regulator is restricted from exceeding this voltage. As the internal battery voltage rises, the battery’s internal impedance and RSENSE work in conjunction with the charge voltage regulation to decrease the amount of current flowing to the battery. Battery charging is completed when the voltage across RSENSE drops below the ITERM threshold. 4. IC www.fairchildsemi.com 16 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Circuit Description / Overview A new charge cycle begins when one of the following occurs: The battery voltage falls below VOREG - VRCH Decimal Hex VOREG VBUS Power on Reset (POR) clears and the battery voltage is below the weak battery threshold (VLOWV). 2 CE or HZ_MODE is reset through I C write to CONTROL1 (R1) register. Decimal Hex VOREG 0 00 3.50 32 20 4.14 1 01 3.52 33 21 4.16 2 02 3.54 34 22 4.18 3 03 3.56 35 23 4.20 Charge Current Limit (IOCHARGE) 4 04 3.58 36 24 4.22 5 05 3.60 37 25 4.24 Table 5. IOCHARGE (REG4 [6:4]) Current as Function of IOCHARGE Bits and RSENSE Resistor Values 6 06 3.62 38 26 4.26 7 07 3.64 39 27 4.28 8 08 3.66 40 28 4.30 9 09 3.68 41 29 10 0A 3.70 42 2A VRSENSE IOCHARGE (mA) (mV) 68 m 100 m DEC BIN HEX 4.32 0 000 00 37.4 550 374 4.34 1 001 01 44.2 650 442 010 02 51.0 750 510 11 0B 3.72 43 2B 4.36 2 12 0C 3.74 44 2C 4.38 3 011 03 57.8 850 578 13 0D 3.76 45 2D 4.40 4 100 04 71.4 1050 714 14 0E 3.78 46 2E 4.42 5 101 05 78.2 1150 782 110 06 91.8 1350 918 111 07 98.6 1450 986 15 0F 3.80 47 2F 4.44 6 16 10 3.82 48 30 4.44 7 17 11 3.84 49 31 4.44 18 12 3.86 50 32 4.44 Termination Current Limit 19 13 3.88 51 33 4.44 20 14 3.90 52 34 4.44 Current charge termination is enabled when TE (REG1[3])=1. Typical termination current values are given in Table 6. 21 15 3.92 53 35 4.44 22 16 3.94 54 36 4.44 23 17 3.96 55 37 4.44 24 18 3.98 56 38 4.44 25 19 4.00 57 39 4.44 26 1A 4.02 58 3A 4.44 27 1B 4.04 59 3B 4.44 28 1C 4.06 60 3C 4.44 29 1D 4.08 61 3D 4.44 30 1E 4.10 62 3E 4.44 Table 6. ITERM Current as Function of ITERM Bits (REG4[2:0]) and RSENSE Resistor Values The following charging parameters can be programmed by the host through I2C: Table 4. Programmable Charging Parameters Parameter Name Register Output Voltage Regulation VOREG REG2[7:2] Battery Charging Current Limit IOCHRG REG4[6:4] Input Current Limit IINLIM REG1[7:6] Charge Termination Limit ITERM REG4[2:0] Weak Battery Voltage VLOWV REG1[5:4] © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 ITERM VRSENSE (mV) 0 3.3 1 2 ITERM (mA) 68 m 100 m 49 33 6.6 97 66 9.9 146 99 3 13.2 194 132 4 16.5 243 165 5 19.8 291 198 6 23.1 340 231 7 26.4 388 264 When the charge current falls below ITERM, PWM charging stops and the STAT bits change to READY (00) for about 500 ms while the IC determines whether the battery and charging source are still connected. STAT then changes to CHARGE DONE (10), provided the battery and charger are still connected. www.fairchildsemi.com 17 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Table 3. OREG Bits (OREG[7:2]) vs. Charger VOUT (VOREG) Float Voltage USB-Friendly Boot Sequence The IC uses a current-mode PWM controller to regulate the output voltage and battery charge currents. The synchronous rectifier (Q2) has a current limit that which off the FET when the current is negative by more than 140mA peak. This prevents current flow from the battery. At VBUS POR, when the battery voltage is above the weak battery threshold (VLOWV), the IC operates in accordance with its I2C register settings. If VBAT < VLOWV, the IC sets all registers to their default values and enables the charger using an input current limit controlled by the OTG pin (100mA if OTG is LOW and 500 mA if OTG is HIGH). This feature can revive a battery whose voltage is too low to ensure reliable host operation. Charging continues in the absence of host communication even after the battery has reached VOREG, whose default value is 3.54 V, and the charger remains active until t15MIN times out. Once the host processor begins writing to the IC, charging parameters are set by the host, which must continually reset the t32S timer to continue charging using the programmed charging parameters. If t32S.times out, the register defaults are loaded, the FAULT bits are set to 110, STAT is pulsed HIGH, and charging continues with default charge parameters. Safety Timer Section references Figure 39. At the beginning of charging, the IC starts a 15-minute timer (t15MIN ). When this times out, charging is terminated. Writing to any register through I2C stops and resets the t15MIN timer, which in turn starts a 32-second timer (t32S). Setting the TMR_RST bit (REG0[7]) resets the t32S timer. If the t32S timer times out; charging is terminated, the registers are set to their default values, and charging resumes using the default values with the t15MIN timer running. Normal charging is controlled by the host with the t32S timer running to ensure that the host is alive. Charging with the t15MIN timer running is used for charging that is unattended by the host. If the t15MIN timer expires; the IC turns off the charger, sets the CE bit, and indicates a timer fault (110) on the FAULT bits (REG0[2:0]). This sequence prevents overcharge if the host fails to reset the t32S timer. Input Current Limiting To minimize charging time without overloading VBUS current limitations, the IC’s input current limit can be programmed by the IINLIM bits (REG1[7:6]). Table 7. Input Current Limit VBUS POR / Non-Compliant Charger Rejection When the IC detects that VBUS has risen above VIN(MIN)1 (4.4 V), the IC applies a 100 load from VBUS to GND. To clear the VBUS POR (Power-On-Reset) and begin charging, VBUS must remain above VIN(MIN)1 and below VBUSOVP for tVBUS_VALID (30 ms) before the IC initiates charging. The VBUS validation sequence always occurs before charging is initiated or re-initiated (for example, after a VBUS OVP fault or a VRCH recharge initiation). IINLIM REG1[7:6] Input Current Limit 00 100 mA 01 500 mA 10 800 mA 11 No limit The OTG pin establishes the input current limit when t15MIN is running. tVBUS_VALID ensures that unfiltered 50 / 60 Hz chargers and other non-compliant chargers are rejected. © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 18 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator PWM Controller in Charge Mode FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Flow Charts VBUS POR YES CE or HZ, CE# DISABLE Pin set? YES VBAT > VLOWV HZ State NO NO Charge Configuration State NO NO T15Min Timer? CE or HZ, CE# DISABLE Pin set? YES NO T32Sec Armed? YES YES CE or HZ, CE# DISABLE Pin set? YES NO HZ State T32Sec Armed? YES NO Charge State Reset all registers Start T15MIN Figure 35. Charger VBUS POR © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 19 CHARGE STATE Disable Charging NO Indicate VBUS Fault VBAT < VSHORT Enable ISHORT , Reset Safety reg YES VBUS OK? NO Indicate Charging NO YES PWM Charging VBUS OK? T15MIN Timeout? YES Indicate Charging NO YES Disable Charging T15MIN Timeout? Indicate VBUS Fault Indicate timer fault YES Set CE Charge Configuration State NO NO HIGHZ mode NO IOUT < ITERM Termination enabled VBAT > VOREG–VRCH VBAT < VOREG–VRCH Indicate Charge Complete YES Reset Safety reg Delay tINT NO YES Battery Removed Stop Charging VBAT < VOREG–VRCH Enable IDET for TDETECT YES Reset charge parameters Figure 36. Charge Mode © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 20 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Flow Charts (Continued) FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Flow Charts (Continued) Charge Configuration State T32Sec ARMED AND CE = 0? CE# YES Charge State NO Has T15Min CE = 0 and CE# NO START T15Min YES VBAT < VOREG for 262ms? NO YES Figure 37. Charge Configuration HZ State DISABLE PIN HIGH Reset T15min if running LOW Stop T32Sec RUN T32Sec NO HZ or CE# CE set? HIGH YES VBAT > VLOWV? YES NO DISABLE PIN LOW Charge State Figure 38. HZ-State © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 21 Charge Start Start T15MIN Reset Registers YES T32SEC NO Expired? Start T32SEC Stop T15MIN T15MIN Active? YES YES NO I2C Write received? NO Timer Fault : Set CE CE T15MIN Expired? NO Continue Charging YES Figure 39. Timer Flow Chart © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 22 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Flow Charts (Continued) The FAN54015 has additional functionality to limit input current in case a current-limited “special charger” is supplying VBUS. These slowly increase the charging current until either: ISAFE (REG6[6:4]) DEC IINLIM or IOCHARGE is reached or VBUS=VSP. BIN HEX VRSENSE (mV) ISAFE (mA) 68 m 100 m 0 000 00 37.4 550 374 1 001 01 44.2 650 442 If VBUS collapses to VSP when the current is ramping up, the FAN54015 charge with an input current that keeps VBUS=VSP. When the VSP control loop is limiting the charge current, the SP bit (REG5[4]) is set. 2 010 02 51.0 750 510 3 011 03 57.8 850 578 4 100 04 71.4 1050 714 Table 8. VSP as Function of SP Bits (REG5[2:0]) 5 101 05 78.2 1150 782 6 110 06 91.8 1350 918 7 111 07 98.6 1450 986 SP (REG5[2:0]) DEC BIN HEX VSP 0 000 00 4.213 1 001 01 4.293 2 010 02 4.373 3 011 03 4.453 4 100 04 4.533 5 101 05 4.613 6 110 06 4.693 7 111 07 4.773 Table 10. VSAFE (VOREG Limit) as Function of VSAFE Bits (REG6[3:0]) VSAFE (REG6[3:0]) Safety Settings DEC BIN HEX Max. OREG (REG2[7:2]) VOREG Max. 0 0000 00 100011 4.20 1 0001 01 100100 4.22 2 0010 02 100101 4.24 3 0011 03 100110 4.26 4 0100 04 100111 4.28 FAN54015 contain a SAFETY register (REG6) that prevents the values in OREG (REG2[7:2]) and IOCHARGE (REG4[6:4]) from exceeding the values of the VSAFE and ISAFE values. 5 0101 05 101000 4.30 6 0110 06 101001 4.32 7 0111 07 101010 4.34 After VBAT exceeds VSHORT, the SAFETY register is loaded with its default value and may be written only before any other register is written. The entire desired Safety register value should be written twice to ensure the register bits are set. After writing to any other register, the SAFETY register is locked until VBAT falls below VSHORT. 8 1000 08 101011 4.36 9 1001 09 101100 4.38 10 1010 0A 101101 4.40 11 1011 0B 101110 4.42 12 1100 0C 101111 4.44 13 1101 0D 110000 4.44 14 1110 0E 110001 4.44 15 1111 0F 110010 4.44 The ISAFE (REG6[6:4]) and VSAFE (REG6[3:0]) registers establish values that limit the maximum values of IOCHARGE and VOREG used by the control logic. If the host attempts to write a value higher than VSAFE or ISAFE to OREG or IOCHARGE, respectively; the VSAFE, ISAFE value appears as the OREG, IOCHARGE register value, respectively. Thermal Regulation and Protection When the IC’s junction temperature reaches T CF (about 120°C), the charger reduces its output current to 550 mA to prevent overheating. If the temperature increases beyond TSHUTDOWN; charging is suspended, the FAULT bits are set to 101, and STAT is pulsed HIGH. In Suspend Mode, all timers stop and the state of the IC’s logic is preserved. Charging resumes at programmed current after the die cools to about 120°C. © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 23 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Table 9. ISAFE (IOCHARGE Limit) as Function of ISAFE Bits (REG6[6:4]) Special Charger Battery Detection During Charging The IC can detect the presence, absence, or removal of a battery if the termination bit (TE) is set. During normal charging, once VBAT is close to VOREG and the termination charge current is detected, the IC terminates charging and sets the STAT bits to 10. It then turns on a discharge current, IDETECT, for tDETECT. If VBAT is still above VOREG – VRCH, the battery is present and the IC sets the FAULT bits to 000. If VBAT is below VOREG – VRCH, the battery is absent and the IC: 1. Sets the registers to their default values. 2. Sets the FAULT bits to 111. 3. Resumes charging with default values after tINT. Table 11. Evaluation Board Measured JA Power (W) JA 0.504 54°C/W 0.844 50°C/W 1.506 46°C/W Battery Short-Circuit Protection If the battery voltage is below the short-circuit threshold (VSHORT); a linear current source, ISHORT, supplies VBAT until VBAT > VSHORT. Charge Mode Input Supply Protection Sleep Mode When VBUS falls below VBAT + VSLP, and VBUS is above VIN(MIN), the IC enters Sleep Mode to prevent the battery from draining into VBUS. During Sleep Mode, reverse current is disabled by body switching Q1. System Operation with No Battery The FAN54015 continues charging after VBUS POR with the default parameters, regulating the VBAT line to 3.54 V until the host processor issues commands or the 15-minute timer expires. In this way, the FAN54015 can start the system without a battery. The FAN54015 soft-start function can interfere with the system supply with battery absent. The soft-start activates whenever VOREG, IINLIM, or IOCHARGE are set from a lower to higher value. During soft-start, the IIN limit drops to 100 mA for about 1ms unless IINLIM is set to 11 (no limit). This could cause the system processor to fail to start. To avoid this behavior, use the following sequence. 1. Set the OTG pin HIGH. When VBUS is plugged in, IINLIM is set to 500 mA until the system processor powers up and can set parameters through I2C. 2. Program the Safety Register. 3. Set IINLIM to 11 (no limit). 4. Set OREG to the desired value (typically 4.18). 5. Reset the IO_LEVEL bit, then set IOCHARGE. 6. Set IINLIM to 500mA if a USB source is connected. Input Supply Low-Voltage Detection The IC continuously monitors VBUS during charging. If VBUS falls below VIN(MIN), the IC: 1. Terminates charging 2. Pulses the STAT pin, sets the STAT bits to 11, and sets the FAULT bits to 011. If VBUS recovers above the VIN(MIN) rising threshold after time tINT (about two seconds), the charging process is repeated. This function prevents the USB power bus from collapsing or oscillating when the IC is connected to a suspended USB port or a low-current-capable OTG device. Input Over-Voltage Detection When the VBUS exceeds VBUSOVP, the IC: 1. Turns off Q3 2. Suspends charging 3. Sets the FAULT bits to 001, sets the STAT bits to 11, and pulses the STAT pin. When VBUS falls about 150 mV below VBUSOVP, the fault is cleared and charging resumes after VBUS is revalidated (see VBUS POR / Non-Compliant Charger Rejection). During the initial system startup, while the charger IC is being programmed, the system current is limited to 500mA for 1ms during steps 4 and 5. This is the value of the softstart ICHARGE current used when IINLIM is set to No Limit. VBUS Short While Charging If VBUS is shorted with a very low impedance while the IC is charging with IINLIMIT=100 mA, the IC may not meet datasheet specifications until power is removed. To trigger this condition, VBUS must be driven from 5 V to GND with a high slew rate. Achieving this slew rate requires a 0 short to the USB cable less than 10cm from the connector. If the system is powered up without a battery present, the CV bit should be set. When a battery is inserted, the CV bit is cleared. Charger Status / Fault Status The STAT pin indicates the operating condition of the IC and provides a fault indicator for interrupt driven systems. Charge Mode Battery Detection & Protection VBAT Over-Voltage Protection The OREG voltage regulation loop prevents VBAT from overshooting the OREG voltage by more than 50 mV when the battery is removed. When the PWM charger runs with no battery, the TE bit is not set and a battery is inserted that is charged to a voltage higher than VOREG; PWM pulses stop. If no further pulses occur for 30 ms, the IC sets the FAULT bits to 100, sets the STAT bits to 11, and pulses the STAT pin. © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 Table 12. STAT Pin Function EN_STAT Charge State STAT Pin 0 X OPEN X Normal Conditions OPEN 1 Charging LOW X Fault (Charging or Boost) 128s Pulse, then OPEN www.fairchildsemi.com 24 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Additional JA data points, measured using the FAN54015 evaluation board, are given in Table 11 (measured with TA=25°C). Note that as power dissipation increases, the effective JA decreases due to the larger difference between the die temperature and ambient. Table 15. Operation Mode Control HZ_MODE OPA_MODE FAULT Operation Mode Table 13. Fault Status Bits During Charge Mode Fault Bit Fault Description B2 B1 B0 0 0 0 Normal (No Fault) 0 0 1 VBUS OVP 0 1 0 Sleep Mode 0 1 1 Poor Input Source 1 0 0 Battery OVP 1 0 1 Thermal Shutdown 1 1 0 Timer Fault 1 1 1 No Battery 0 0 0 Charge 0 X 1 Charge Configure 0 1 0 Boost 1 X X High Impedance The IC resets the OPA_MODE bit whenever the boost is deactivated, whether due to a fault or being disabled by setting the HZ_MODE bit. Boost Mode Boost Mode can be enabled if the IC is in 32-Second Mode with the OTG pin and OPA_MODE bits as indicated in Table 16. The OTG pin ACTIVE state is 1 if OTG_PL=1 and 0 when OTG_PL=0. If boost is active using the OTG pin, Boost Mode is initiated even if the HZ_MODE=1. The HZ_MODE bit overrides the OPA_MODE bit. Charge Mode Control Bits Setting either HZ_MODE or CE through I2C disables the charger and puts the IC into High-Impedance Mode and resets t32S. If VBAT < VLOWV while in High-Impedance Mode, t32S begins running and, when it overflows, all registers (except SAFETY) reset, which enables t15MIN charging on versions with the 15-minute timer. Table 16. Enabling Boost When t15MIN overflows, the IC sets the CE bit and the IC enters High-Impedance Mode. If CE was set by t15MIN overflow, a new charge cycle can only be initiated through I2C or VBUS POR. Setting the RESET bit clears all registers. If HZ_MODE or CE bits were set when the RESET bit is set, these bits are also cleared, but the t32S timer is not started, and the IC remains in High-Impedance Mode. DISABLE Pin CE HZ_MODE ENABLE 0 0 0 DISABLE X 1 X DISABLE X X 1 DISABLE 1 X X OTG Pin HZ_ MODE OPA_ MODE BOOST 1 ACTIVE X X Enabled X X 0 1 Enabled X ACTIVE X 0 Disabled 0 X 1 X Disabled 1 ACTIVE 1 1 Disabled 0 ACTIVE 0 0 Disabled To remain in Boost Mode, the TMR_RST must be set by the host before the t32S timer times out. If t32S times out in Boost Mode; the IC resets all registers, pulses the STAT pin, sets the FAULT bits to 110, and resets the BOOST bit. VBUS POR or reading R0 clears the fault condition. Table 14. DISABLE Pin and CE Bit Functionality Charging OTG_EN Boost PWM Control Raising the DISABLE pin stops t32S from advancing, but does not reset it. If the DISABLE pin is raised during t15MIN charging, the t15MIN timer is reset. The IC uses a minimum on-time and computed minimum offtime to regulate VBUS. The regulator achieves excellent transient response by employing current-mode modulation. This technique causes the regulator to exhibit a load line. During PWM Mode, the output voltage drops slightly as the input current rises. With a constant VBAT, this appears as a constant output resistance. Operational Mode Control OPA_MODE (REG1[0]) and the HZ_MODE (REG1[1]) bits in conjunction with the FAULT state define the operational mode of the charger. The “droop” caused by the output resistance when a load is applied allows the regulator to respond smoothly to load transients with no undershoot from the load line. This can be seen in Figure 31 and Figure 40. © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 25 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator The FAULT bits (R0[2:0]) indicate the type of fault in Charge Mode (see Table 13). When PMID > VBAT – 400 mV, the boost regulator begins switching with a reduced peak current limit of about 50% of its normal current limit. The output slews up until VBUS is within 5% of its setpoint; at which time, the regulation loop is closed and the current limit is set to 100%. Output Resistance (mW) 325 300 275 If the output fails to achieve 95% of its setpoint (VBST) within 128 s, the current limit is increased to 100%. If the output fails to achieve 95% of its setpoint after this second 384s period, a fault state is initiated. 250 225 BST State 200 2.0 2.5 3.0 3.5 4.0 4.5 5.0 This is the normal operating mode of the regulator. The regulator uses a minimum tOFF-minimum tON modulation Battery Voltage, VBAT (V) Figure 40. Output Resistance (ROUT) scheme. The minimum tOFF is proportional to keeps the regulator’s switching frequency reasonably constant in CCM. tON(MIN) is proportional to VBAT and is a higher value if the inductor current reached 0 before tOFF(MIN) in the prior cycle. VBUS as a function of ILOAD can be computed when the regulator is in PWM Mode (continuous conduction) as: VOUT 5.07 ROUT ILOAD EQ. 1 To ensure the VBUS does not pump significantly above the regulation point, the boost switch remains off as long as FB > VREF. At VBAT=3.3 V, and ILOAD=200 mA, VBUS would drop to: VOUT 5.07 0.26 0.2 5.018V EQ. 1A Boost Faults At VBAT=2.7 V, and ILOAD=200 mA, VBUS would drop to: VOUT 5.07 0.327 0.2 5.005V If a BOOST fault occurs: 1. The STAT pin pulses. 2. OPA_MODE bit is reset. 3. The power stage is in High-Impedance Mode. 4. The FAULT bits (REG0[2:0]) are set per Table 18. EQ. 1B PFM Mode If VBUS > VREFBOOST (nominally 5.07 V) when the minimum off-time has ended, the regulator enters PFM Mode. Boost pulses are inhibited until VBUS < VREFBOOST. The minimum on-time is increased to enable the output to pump up sufficiently with each PFM boost pulse. Therefore the regulator behaves like a constant on-time regulator, with the bottom of its output voltage ripple at 5.07 V in PFM Mode. Restart After Boost Faults If boost was enabled with the OPA_MODE bit and OTG_EN=0, Boost Mode can only be enabled through subsequent I2C commands since OPA_MODE is reset on boost faults. If OTG_EN=1 and the OTG pin is still ACTIVE (see Table 16), the boost restarts after a 5.2 ms delay, as shown in Figure 41. If the fault condition persists, restart is attempted every 5ms until the fault clears or an I2C command disables the boost. Table 17. Boost PWM Operating States Mode Description Invoked When LIN Linear Startup VBAT > VBUS SS Boost Soft-Start VBUS < VBST Boost Operating Mode VBAT > UVLOBST and SS Completed BST VIN , which VOUT Table 18. Fault Bits During Boost Mode Fault Bit B2 B1 B0 Fault Description Startup 0 0 0 Normal (no fault) When the boost regulator is shut down, current flow is prevented from VBAT to VBUS, as well as reverse flow from VBUS to VBAT. 0 0 1 VBUS > VBUSOVP LIN State 0 1 0 VBUS fails to achieve the voltage required to advance to the next state during soft-start or sustained (>50 s) current limit during the BST state. 0 1 1 VBAT < UVLOBST 1 0 0 N/A: This code does not appear. 1 0 1 Thermal shutdown 1 1 0 Timer fault; all registers reset. 1 1 1 N/A: This code does not appear. When EN rises, if VBAT > UVLOBST, the regulator first attempts to bring PMID within 400 mV of VBAT using an internal 450 mA current source from VBAT (LIN State). If PMID has not achieved VBAT – 400 mV after 560 s, a FAULT state is initiated. © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 26 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator SS State 350 560 5200 450mA BATTERY CURRENT 0 Monitor Register (Reg10H) 64 BOOST ENABLED Additional status monitoring bits enable the host processor to have more visibility into the status of the IC. The monitor bits are real-time status indicators and are not internally debounced or otherwise time qualified. Figure 41. Boost Response Attempting to Start into VBUS Short Circuit (Times in s) VREG Pin The state of the MONITOR register bits listed in HighImpedance Mode is only valid when VBUS is valid. The 1.8 V regulated output on this pin can be disabled through I2C by setting the DIS_VREG bit (REG5[6]). VREG Table 19. MONITOR Register Bit Definitions BIT# MONITOR 7 STATE NAME 0 1 Active When Address 10H ITERM_CMP VCSIN – VBAT < VITERM VCSIN – VBAT > VITERM Charging with TE=1 VCSIN – VBAT < 1 mV VCSIN – VBAT > 1mV Charging with TE=0 VBAT < VSHORT VBAT > VSHORT Charging VBAT < VLOWV VBAT > VLOWV High-Impedance Mode 6 VBAT_CMP VBAT < UVLOBST VBAT > UVLOBST Boosting 5 LINCHG Linear Charging Not Enabled Linear Charging Enabled Charging 4 T_120 TJ < 120°C TJ > 120°C 3 ICHG Charging Current Controlled by ICHARGE Control Loop Charging Current Not Controlled by ICHARGE Control Loop Charging 2 IBUS IBUS Limiting Charging Current Charge Current Not Limited by IBUS Charging 1 VBUS_VALID VBUS Not Valid VBUS is Valid VBUS > VBAT 0 CV Constant Current Charging Constant Voltage Charging Charging © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 27 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator can supply up to 2 mA. This circuit, which is powered from PMID, is enabled only when PMID > VBAT and does not drain current from the battery. During boost, VREG is off. It is also off when the HZ_MODE bit (REG1[1])=1. VBUS 0 The FAN54015’s serial interface is compatible with Standard, Fast, Fast Plus, and High-Speed Mode I2C-Bus® specifications. The SCL line is an input and the SDA line is a bi-directional open-drain output; it can only pull down the bus when active. The SDA line only pulls LOW during data reads and signaling ACK. All data is shifted in MSB (bit 7) first. During a read from the FAN54015 (Figure 46, Figure 47), the master issues a Repeated Start after sending the register address and before resending the slave address. The Repeated Start is a 1-to-0 transition on SDA while SCL is HIGH, as shown in Figure 45. High-Speed (HS) Mode Slave Address The protocols for High-Speed (HS), Low-Speed (LS), and Fast-Speed (FS) Modes are identical except the bus speed for HS Mode is 3.4 MHz. HS Mode is entered when the bus master sends the HS master code 00001XXX after a start condition. The master code is sent in Fast or Fast Plus Mode (less than 1 MHz clock); slaves do not ACK this transmission. Table 20. I2C Slave Address Byte Part Type 7 6 5 4 3 2 1 0 FAN54015 1 1 0 1 0 1 0 R/ W In hex notation, the slave address assumes a 0 LSB. The hex slave address for the FAN54015 is D4H and is D6H for all other parts in the family. The master then generates a repeated start condition (Figure 45) that causes all slaves on the bus to switch to HS Mode. The master then sends I2C packets, as described above, using the HS Mode clock rate and timing. Bus Timing As shown in Figure 42, data is normally transferred when SCL is LOW. Data is clocked in on the rising edge of SCL. Typically, data transitions shortly at or after the falling edge of SCL to allow ample time for the data to set up before the next SCL rising edge. The bus remains in HS Mode until a stop bit (Figure 44) is sent by the master. While in HS Mode, packets are separated by repeated start conditions (Figure 45). Slave Releases SDA Data change allowed SDA SLADDR MS Bit Figure 45. Repeated Start Timing TSU SCL Figure 42. Data Transfer Timing Each bus transaction begins and ends with SDA and SCL HIGH. A transaction begins with a START condition, which is defined as SDA transitioning from 1 to 0 with SCL HIGH, as shown in Figure 43. THD;STA Read and Write Transactions The figures below outline the sequences for data read and write. Bus control is signified by the shading of the packet, Master Drives Bus defined as and All addresses and data are MSB first. Slave Address MS Bit Slave Drives Bus . Table 21. Bit Definitions for Figure 46, Figure 47, and Figure 48 SCL Symbol Figure 43. Start Bit A transaction ends with a STOP condition, which is defined as SDA transitioning from 0 to 1 with SCL HIGH, as shown in Figure 44. Slave Releases SDA tHD;STA SCL TH SDA tSU;STA ACK(0) or NACK(1) Master Drives tHD;STO ACK(0) or NACK(1) Definition S START, see Figure 43 A ACK. The slave drives SDA to 0 to acknowledge the preceding packet. A NACK. The slave sends a 1 to NACK the preceding packet. R Repeated START, see Figure 45 P STOP, see Figure 44. Figure 44 SCL Figure 44. Stop Bit © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 28 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator I2C Interface S Slave Address 0 0 8 bits 0 8 bits 0 A Reg Addr A Data A P Figure 46. Write Transaction 7 bits S Slave Address 0 0 8 bits 0 A Reg Addr A 7 bits R Slave Address 1 0 8 bits 1 A Data A P Figure 47. Read Transaction Register Descriptions The nine FAN54015 user-accessible registers are defined in Table 22. Table 22. I2C Register Address Register Address Bits Name REG# 7 6 5 4 3 2 1 0 CONTROL0 0 0 0 0 0 0 0 0 0 CONTROL1 1 0 0 0 0 0 0 0 1 OREG 2 0 0 0 0 0 0 1 0 IC_INFO 03 or 3BH 0 0 0 0 0 0 1 1 IBAT 4 0 0 0 0 0 1 0 0 SP_CHARGER 5 0 0 0 0 0 1 0 1 SAFETY 6 0 0 0 0 0 1 1 0 MONITOR 10h 0 0 0 0 1 0 1 0 Table 23. Register Bit Definitions This table defines the operation of each register bit for all IC versions. Default values are in bold text. Bit Name Value Type CONTROL0 7 6 TMR_RST OTG EN_STAT Register Address: 00 1 0 STAT Writing a 1 resets the t32S timer; writing a 0 has no effect R Returns the OTG pin level (1=HIGH) R/W Enables STAT pin LOW when IC is charging R BOOST 2:0 FAULT Ready Charge in progress 10 Charge done 11 3 Prevents STAT pin from going LOW during charging; STAT pin still pulses to enunciate faults 01 0 Default Value=X1XX 0XXX W 1 00 5:4 Description Fault R 1 IC is not in Boost Mode IC is in Boost Mode R Fault status bits: for Charge Mode, see Table 13; for Boost Mode, see Table 18 Continued on the following page… © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 29 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator 7 bits Bit Name Value Type CONTROL1 7:6 Register Address: 01 IINLIM 00 5:4 VLOWV R/W Input current limit, see Table 7 R/W 3.4V 01 3.5V 10 3.6V 11 3.7V R/W Disable charge current termination TE 1 0 2 CE Enable charge current termination R/W 1 0 1 Charger enabled Charger disabled R/W Not High-Impedance Mode HZ_MODE 1 0 0 Default Value=0011 0000 (30h) Weak battery voltage threshold 0 3 Description High-Impedance Mode R/W See Table 16 Charge Mode OPA_MODE 1 Boost Mode OREG Register Address: 02 7:2 OREG 1 OTG_PL 0 R/W Charger output “float” voltage; programmable from 3.5 to 4.44V in 20mV increments; defaults to 000010 (3.54V), see Table 3 R/W OTG pin active LOW 1 0 0 Default Value=0000 1010 (0Ah) OTG pin active HIGH R/W Disables OTG pin OTG_EN 1 Enables OTG pin IC_INFO Register Address: 03 7:5 Vendor Code 4:2 PN 1:0 REV 100 00 Default Value=10010100 (94h) R Identifies Fairchild Semiconductor as the IC supplier R Part number bits, see the Ordering Info on page 2 R IC Revision, revision 1.X, where X is the decimal of these three bits IBAT Register Address: 04 7 RESET 1 W 6:4 IOCHARGE Table 5 R/W 3 Reserved 1 R 2:0 ITERM Table 6 R/W Default Value=1000 1001 (89h) Writing a 1 resets charge parameters, except the Safety register (Reg6), to their defaults: writing a 0 has no effect; read returns 1 Programs the maximum charge current, see Table 5 Unused Sets the current used for charging termination, see Table 6 Continued on the following page… © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 30 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Table 23. Register Bit Definitions (Continued) SP_CHARGER 7 Reserved 6 DIS_VREG Register Address: 05 0 R 0 R/W 1 0 5 IO_LEVEL 4 SP 3 EN_LEVEL 2:0 VSP R Output current is controlled by IOCHARGE bits Special charger is not active (VBUS is able to stay above VSP) Special charger has been detected and VBUS is being regulated to VSP R 1 Table 8 1.8V regulator is ON Voltage across RSENSE for output current control is set to 34mV (500mA for RSENSE=68m and 340mA for 100m) 1 0 Unused 1.8V regulator is OFF R/W 1 0 Default Value=001X X100 DISABLE pin is LOW DISABLE pin is HIGH R/W SAFETY Special charger input regulation voltage, see Table 8 Register Address: 06 Default Value=0100 0000 (40h) 7 Reserved 0 R 6:4 ISAFE Table 9 R/W Sets the maximum IOCHARGE value used by the control circuit, see Table 9 3:0 VSAFE Table 10 R/W Sets the maximum VOREG used by the control circuit, see Table 10 MONITOR Bit disabled and always returns 0 when read back Register Address: 10h (16) See Table 19 7 ITERM_CMP R ITERM comparator output, 1 when VRSENSE > ITERM reference 6 VBAT_CMP R Output of VBAT comparator 5 LINCHG R 30mA linear charger ON 4 T_120 R Thermal regulation comparator; when=1 and T_145=0, the charge current is limited to 22.1 mV across RSENSE 3 ICHG R 0 indicates the ICHARGE loop is controlling the battery charge current See Table 19 2 IBUS R 0 indicates the IBUS (input current) loop is controlling the battery charge current 1 VBUS_VALID R 1 indicates VBUS has passed validation and is capable of charging 0 CV R 1 indicates the constant-voltage loop (OREG) is controlling the charger and all current limiting loops have released © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 31 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Table 23. Register Bit Definitions (Continued) Bypass capacitors should be placed as close to the IC as possible. In particular, the total loop length for CMID should be minimized to reduce overshoot and ringing on the SW, PMID, and VBUS pins. All power and ground pins must be routed to their bypass capacitors, using top copper whenever possible. Copper area connecting to the IC should be maximized to improve thermal performance if possible. Figure 48. PCB Layout Recommendations © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 32 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator PCB Layout Recommendations BALL A1 INDEX AREA F A E 1.20 B 1.20 Ø0.20 A1 Cu Pad 0.03 C 2X 1.60 D Ø0.215 Cu Pad A1 Ø0.30 Solder Mask Opening 0.40 Ø0.315 Solder Mask Opening 0.40 0.03 C 0.40 option 1 2X TOP VIEW option 2 RECOMMENDED LAND PATTERN (NSMD TYPE) 0.06 C 0.625 0.547 0.05 C 0.378±0.018 0.208±0.021 E C SEATING PLANE SIDE VIEWS D NOTES: 0.005 1.20 A. NO JEDEC REGISTRATION APPLIES. C A B B. DIMENSIONS ARE IN MILLIMETERS. Ø0.260±0.02 20X 0.40 E D C B A 1.60 0.40 C. DIMENSIONS AND TOLERANCE PER ASMEY14.5M, 1994. D. DATUM C IS DEFINED BY THE SPHERICAL CROWNS OF THE BALLS. (Y) ±0.018 E. PACKAGE NOMINAL HEIGHT IS 586 MICRONS ±39 MICRONS (547-625 MICRONS). F 1 2 3 4 (X) ±0.018 F. FOR DIMENSIONS D, E, X, AND Y SEE PRODUCT DATASHEET. BOTTOM VIEW G. DRAWING FILNAME: MKT-UC020AArev3. Figure 49. 20-Ball WLCSP, 4X5 Array, 0.4 mm Pitch, 250 µm Ball Product-Specific Dimensions Product D E X Y FAN54015UCX 1.960 +0.030 mm 1.870 +0.030 mm 0.335 mm 0.180 mm FAN54015BUCX 1.960 +0.030 mm 1.870 +0.030 mm 0.335 mm 0.180 mm Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the warranty therein, which covers Fairchild products. Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings: http://www.fairchildsemi.com/dwg/UC/UC020AA.pdf. © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2 www.fairchildsemi.com 33 FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator Physical Dimensions FAN54015 — USB-Compliant Single-Cell Li-Ion Switching Charger with USB-OTG Boost Regulator 34 www.fairchildsemi.com © 2012 Fairchild Semiconductor Corporation FAN54015 • Rev. 1.0.2