MP2605 28V, 1A Li-Ion/Li-Polymer Battery Charger with Trickle Charge and Timer The Future of Analog IC Technology DESCRIPTION FEATURES The MP2605 is a linear, high-performance single cell Li-Ion/Li-Polymer battery charger. By integrating high voltage input protection into the charger IC, the MP2605 can tolerate an input surge up to +28V. • • Proprietary VIN Surge Protection up to 28V Programmable Charge Current : 200mA to 1.0A Trickle Charge 40µA Shutdown Current 7V Input OVP Auto Recharge Charge-Timer Fault and Charge Status Indicators • • • • • • The device features constant current (CC) and constant voltage (CV) charging modes with programmable charge currents (200mA to 1A), current blocking, and trickle charge. The device also provides fault and charge status indications to the system. APPLICATIONS • • • • • For guaranteed safe operation, the MP2605 reduces charge current when the device reaches high temperature (due to limited PCB space). Other safety features include battery temperature monitoring and programmable timer to complete the charging cycle. Cell Phones Digital Cameras Smart Phones PDAs MP3 Players “MPS” and “The Future of Analog IC Technology” are Registered Trademarks of Monolithic Power Systems, Inc. The MP2605 is available in 10-pin 3mm x 3mm QFN packages. TYPICAL APPLICATION 3.5V - 6.5V VIN To system IBATT 1 2 3 4 5 IN BATT NTC ACOK 10 9 MP2605 CHG ISET 8 TMR SS GND SHDN VBATT 7 6 CSS ON OFF MP2605 Rev. 0.94 1/25/2010 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2010 MPS. All Rights Reserved. 1 MP2605 – 28V, 1A LINEAR BATTERY CHARGER WITH TRICKLE CHARGE AND TIMER ORDERING INFORMATION Part Number* Package Top Marking Free Air Temperature (TA) MP2605DQ QFN10 (3mm x 3mm) U4YW -40°C to +85°C * For Tape & Reel, add suffix –Z (e.g. MP2605DQ–Z). For RoHS Compliant packaging, add suffix –LF (e.g. MP2605DQ–LF–Z) PACKAGE REFERENCE 1 10 2 9 3 8 4 7 5 6 ABSOLUTE MAXIMUM RATINGS (1) IN to GND .....................................-0.3V to +28V ACOK and CHG Maximum Sink Current..... 20mA All Other Pins to GND ..................-0.3V to +6.5V (2) Continuous Power Dissipation (TA = +25°C) ………………………………………………....2.5W Junction Temperature ...............................140°C Lead Temperature ....................................260°C Storage Temperature............... -65°C to +150°C Recommended Operating Conditions (3) Nominal Supply Voltage VIN ............3.5V to 6.5V Operating Junct. Temp (TJ)...... -40°C to +125°C MP2605 Rev. 0.94 1/25/2010 Thermal Resistance (4) θJA θJC 3x3 QFN10..............................50 ...... 12 ... °C/W Notes: 1) Exceeding these ratings may damage the device. 2) The maximum allowable power dissipation is a function of the maximum junction temperature TJ (MAX), the junction-toambient thermal resistance θJA, and the ambient temperature TA. The maximum allowable continuous power dissipation at any ambient temperature is calculated by PD (MAX) = (TJ (MAX)-TA)/θJA. Exceeding the maximum allowable power dissipation will cause excessive die temperature, and the regulator will go into thermal shutdown. Internal thermal shutdown circuitry protects the device from permanent damage. 3) The device is not guaranteed to function outside of its operating conditions. 4) Measured on JESD51-7, 4-layer PCB www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2010 MPS. All Rights Reserved. 2 MP2605 – 28V, 1A LINEAR BATTERY CHARGER WITH TRICKLE CHARGE AND TIMER ELECTRICAL CHARACTERISTICS VIN = 5V, VSHDN = 0V, TA = +25°C, unless otherwise noted. Parameter Symbol Supply Current ISUPPLY Battery Voltage Regulation VBATT Condition SHDN = High SHDN= Low, ICHG = 0A, VBATT=4.1V T = -5°C to +75°C, IBATT = 0 VIN = 5V, VBATT = 3.8V RCHG = 3.3kΩ VIN = 5V, VBATT = 3.8V, TJ = 0°C to +120°C, RCHG = 1.6kΩ to 8.0kΩ Min Typ Max Units 40 µA 200 µA 4.16 4.20 4.24 V 448 515 582 mA 87 100 113 %ICHG(4) 5 2.45 20 10 2.6 100 15 2.75 %ICHG(4) %ICHG(4) V mV Input ACOK Up Range 6.7 7 7.3 V Input ACOK Low Range 1.5 2 2.5 V Constant Current Regulation ICHG Constant Current Variation End of Charge Threshold Trickle Current Trickle Threshold Voltage Trickle Voltage Hysteresis ACOK and CHG Overvoltage Clamp Input Over Voltage Protection OVP Hysteresis SHDN Trip Threshold High SHDN Trip Threshold Low SHDN Pull up Current IBF VIN = 5V, VBATT = 2.3V VZ OVP VIN Rising 6.7 7 V 7.3 400 2.6 0.4 ISHDN VSHDN=3V Pin Voltage = 0.4V CHG , ACOK Sink Current Battery Reverse Current to BATT Pin Dropout voltage 8.2 VIN-VBATT 6 8 mV V V µA mA SHDN = Low and Input = Floating or 0V VBATT = 3.8V, RCHG = 6kΩ. Current drop 10% Die temperature Limit Recharge Voltage Threshold VRECHARGE Recharge Voltage hysteresis V 1 0.25 105 3.9 120 4.0 100 µA V 135 4.1 °C V mV R_NTC at 0°C Note: R_NTC is 100k at 25°C R_NTC=TH11-4H104F 376.6 kΩ R_NTC at 50°C Note: R_NTC is 100k at 25°C R_NTC=TH11-4H104F 32.3 kΩ MP2605 Rev. 0.94 1/25/2010 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2010 MPS. All Rights Reserved. 3 MP2605 – 28V, 1A LINEAR BATTERY CHARGER WITH TRICKLE CHARGE AND TIMER ELECTRICAL CHARACTERISTICS (continued) VIN = 5V, VSHDN = 0V, TA = +25°C, unless otherwise noted. Parameter Symbol Oscillation Freq Condition Min Typ Max Units CTMR = 2.2uF 5 Hz TMR Pin Source Current ITMR1 VTMR=0.1V 20 µA TMR Pin Sink Current ITMR2 VTMR=1.5V 20 µA Soft Start Time From Trickle to 90% Full Current, CSS=0.1µF 70 80 90 mS Notes: 5) ICHG is the target preprogrammed charge current (Die temperature below 110°C). MP2605 Rev. 0.94 1/25/2010 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2010 MPS. All Rights Reserved. 4 MP2605 – 28V, 1A LINEAR BATTERY CHARGER WITH TRICKLE CHARGE AND TIMER PIN FUNCTIONS Pin # Name 1 VIN 2 ACOK 3 CHG 4 TMR 5 6 7 Description Input Supply Pin. VIN receives the AC adapter or USB supply voltage. Open-Drain Fault Status Indicator. This pin is high under any fault conditions. Open-Drain Charge Indicator. This pin is low during charging, is high after battery full or termination, and is toggling when the battery is in fault condition. Oscillator Period Timer. Connect a timing capacitor between this pin and GND to set the oscillator period. GND, Exposed The exposed pad and GND pin must be connected to the same ground plane. Pad SHDN Charger IC Enable. An input “Low” signal at this pin or pin floating will enable the IC. Soft-Start. Connect a capacitor to ground to set the soft-start time. The rising time SS constant is 400 × 10 3 × C SS , where CSS is in µF. 8 ISET 9 NTC 10 BATT MP2605 Rev. 0.94 1/25/2010 Constant Charge Current Program Pin. Connect this pin to an external resistor to program the charging current in CC Mode. Negative Temperature Coefficient (NTC) Thermistor Pin. Connect a 500kΩ resistor from this pin to the VIN pin and a 100kΩ NTC resistor (within the battery pack) from this pin to ground. If NTC function is not used, replace NTC resistor with a regular 100kΩ resistor from this pin to ground. Do not leave this pin floating. Charger Output. www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2010 MPS. All Rights Reserved. 5 MP2605 – 28V, 1A LINEAR BATTERY CHARGER WITH TRICKLE CHARGE AND TIMER BLOCK DIAGRAM IN SS NTC VIN CIN 1 7 9 BATT I BATT RNTC 10 TMR CTMR ISET 8.2V 4 BATTERY CHARGE CONTROL CHG + VBATT _ COUT 3 VZ 8 RCHG 8.2V ACOK 2 VZ 6 ON OFF SHDN 5 GND Figure 1—Functional Block Diagram MP2605 Rev. 0.94 1/25/2010 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2010 MPS. All Rights Reserved. 6 MP2605 – 28V, 1A LINEAR BATTERY CHARGER WITH TRICKLE CHARGE AND TIMER TYPICAL PERFORMANCE CURVES CIN = 4.7µF, COUT = 2.2 µF, VIN = 5V, TA = +25°C, unless otherwise noted. Battery Charge Curve 1000 Charge Current vs Battery Voltage 5 1200 4 1000 800 ICHG (mA) 3 400 2 VBAT (V) 600 ICHG (mA) VBAT I CHG=1A 800 I CHG=0.8A 600 I CHG=0.5A 400 200 0 1 ICHG 0 30 60 90 120 150 TIME (Min) 0 180 0 Charge Current vs Battery Voltage 0 1.0 2.0 3.0 VBAT (V) 4.0 5.0 0.6 1200 I CHG=1A 1000 1000 ICHG (mA) I CHG=0.8A 800 I CHG=0.5A 600 400 800 VBAT=4V 0.5 VBAT=4.1V 200 3.0 3.3 3.6 3.9 0.4 600 0.3 400 0.2 200 0.1 I CHG=0.2A 0 2.7 1/RSET vs. ISET ICHG Current vs Input Voltage 1200 ICHG (mA) I CHG=0.2A 200 0 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5.0 VIN (V) 4.2 VBAT (V) 0 0 200 400 600 ISET (mA) 800 Shut Down Low Shut Down High Power Ramp Up VIN = 5V, ISET Resistor = 2.26K VIN = 5V, ISET Resistor = 2.26K VBAT = 3.8V VIN = 5V, ISET Resistor = 2.26K VIN 5V/div. VSD 2V/div. VIN 5V/div. VSD 2V/div. VBAT 2V/div. VBAT 2V/div. ICHG 0.5A/div. MP2605 Rev. 0.94 1/25/2010 VIN 5V/div. VCHG 5V/div. VBAT 2V/div. ICHG 0.5A/div. ICHG 0.5A/div. 4ms/div. 1000 4ms/div. www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2010 MPS. All Rights Reserved. 4ms/div. 7 MP2605 – 28V, 1A LINEAR BATTERY CHARGER WITH TRICKLE CHARGE AND TIMER TYPICAL PERFORMANCE CURVES (continued) CIN = 4.7µF, COUT = 2.2 µF, VIN = 5V, TA = +25°C, unless otherwise noted. MP2605 Rev. 0.94 1/25/2010 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2010 MPS. All Rights Reserved. 8 MP2605 – 28V, 1A LINEAR BATTERY CHARGER WITH TRICKLE CHARGE AND TIMER OPERATION Input Voltage Range The MP2605 has built-in input voltage surge protection as high as +28V. The charger IC will be automatically disabled when the input voltage is lower than 3.0V or higher than 7.0V. The open-drain pin ACOK is used to indicate an input power good condition (i.e. 3.0V<VIN<7.0V). If the input voltage is lower than the battery voltage, the IC is also disabled to prevent the battery from draining. Charge Cycle (Mode Change: Trickle -> CC-> CV) Figure 2 shows the typical charging profile for the MP2605. For a fully depleted battery with a terminal voltage lower than 2.6V, the MP2605 will start with the trickle charge (preconditioning) at 10% of the full charge current based on the value of RCHG. If the charger stays in trickle mode longer than 32768 cycles, the battery fault condition will be indicated by flashing the CHG LED. After the battery voltage reaches 2.6V, the charger begins charging using the programmed charge current (ICHG).This is referred to as Constant Current (CC) mode. Once the battery voltage reaches 4.2V, the charger will operate in the constant voltage (CV) mode until the battery is fully charged. The charge current drops during CV mode, and the battery full indication is set when the charge current is reduced to 20% of the programmed constant current value (ICHG). The charge process is then terminated. Recharge will start after the battery voltage is reduced to 4.0V. After 262144 cycles of continuous charging, if the battery still has not reached 20% of the ICHG condition, the on-chip timer will terminate the charger to prevent charging the dead battery excessively and the fault condition will be flagged by flashing the CHG LED. Charge Termination The charge current will gradually decrease in CV mode as the battery approaches full. The MP2605 Rev. 0.94 1/25/2010 battery full threshold is internally programmed to be 20% of the ICHG. When the charge current reaches this threshold, the charger IC will be automatically turned off. IBATT CC Charging ICHG CV Charging 20% of ICHG 10% of ICHG Charging Complete Trickle Charging VBATT 2.6V 4.2V Figure 2—MP2605 Typical Charging Profile Automatic Recharge When VBATT drops to 4.0V, the charger will automatically restart the charge cycle until the 20% ICHG condition is met again. When the input adapter is unplugged, or the charger is disabled and/or terminated, the leakage current from the battery to the MP2605 is less than 1uA. Programming of Charge Current and Battery Full Current The charge current (ICHG) is set by a resistor (RCHG) connected from the ISET pin to GND, R CHG (kΩ) = 1700 / ICHG (mA ) . The relationship between the charge current and the programming resistance is established by the following table and graph. Table 1—RCHG and ICHG Relationship RCHG (kΩ) 1.65 1.82 2.05 2.32 2.74 3.3 4.12 5.6 8.45 15 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2010 MPS. All Rights Reserved. ICHG (mA) 1000 900 800 700 600 500 400 300 200 100 9 MP2605 – 28V, 1A LINEAR BATTERY CHARGER WITH TRICKLE CHARGE AND TIMER Charge Current vs. 1/RCHG CHARGE CURRENT (mA) 1000 900 800 700 600 500 400 300 200 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Figure 3—Charge Current vs. 1/RCHG Resistance The recommended resistance for programming the charge current is 2.3kΩ<RCHG<11kΩ. The open-drain pin CHG is used to indicate charging status. When the battery full condition is met or any other condition prevents the charger from charging, CHG will become a floating pin. Negative Thermal Coefficient (NTC) Thermistor The MP2605 has a built-in NTC resistance window comparator. If configured as the typical application circuit as indicated in Figure 1, the MP2605 will cease charging if RNTC<32.3kΩ or RNTC>376.6kΩ. This represents a valid charging temperature range of 0°C to 50°C for the TH11-4H104F NTC resistor. MP2605 Rev. 0.94 1/25/2010 Timer Operation The TMR pin is used to set the internal µF . The oscillator frequency, FOSC = 11Hz × CTMR on-chip timer will start to count down after initial power-up or every time it is enabled. This timer will limit the max trickle-charge time to 32768 internal oscillating cycles. If the charger stays in trickle mode for longer than 32768 cycles, it will be terminated and a fault will be set by floating CHG pin. After fault reporting, the charger can be re-initiated only by recycling the power supply or SHDN signal. If the charger successfully goes through trickle charge within the allowed time limit, it will start CC charging and then CV charging. If the total charge time exceeds 262144 cycles and the battery full has not been qualified, the charger will be terminated and a fault will also be set by flashing CHG pin at the rate of half the internal oscillation frequency. This function prevents charging a dead battery for prolonged duration. The timer function can be disabled by shorting TMR to ground. Thermal Protection The MP2605 has proprietary thermal protection to prevent the IC from overheating. When in thermal protection mode, the average charge current will be reduced to prevent the IC from overheating. Operating in thermal protection mode will slow down the charging process. Lowering the input voltage and enhancing thermal dissipation to the environment can effectively prevent the IC from going into thermal protection mode. www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2010 MPS. All Rights Reserved. 10 MP2605 – 28V, 1A LINEAR BATTERY CHARGER WITH TRICKLE CHARGE AND TIMER Under full charge conditions, certain systems may draw a very narrow current pulse that exceeds the IBF threshold. The CHG indicator may glitch. It is desirable to blank the CHG glitch so that the system can properly indicate full charge conditions to the user. A simple solution is to add a RC filter on the CHG pin to filter out the possible CHG glitch, as shown in Figure 4. Charger Status Indication The MP2605 has an integrated charge status pin that remains low while the battery is charging. Once the charge current threshold (IBF) is reached, the CHG pin will become high impedance. For different operation state, CHG indication is as Table 2 shows. Table 2— CHG Indication for different Charge State SHDN = High Vin Fault CHG HIGH Battery Full Time out Fault Ambient Temperature Fault In Charging HIGH Toggled at the −6 frequency 11× 10 Hz C TMR (µF) HIGH LOW ACOK is LOW while 3.0V<VIN<7V, otherwise it is HIGH. 2 1 6 9 7 IN 3 C HG AC OK B AT 10 SD IS ET NTC SS TM R 8 4 GND 5 Figure 4—Filtered Charge Status with GPIO Connection MP2605 Rev. 0.94 1/25/2010 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2010 MPS. All Rights Reserved. 11 MP2605 – 28V, 1A LINEAR BATTERY CHARGER WITH TRICKLE CHARGE AND TIMER APPLICATION Flow Chart of Operation Power-On Reset (POR) feature can be applied to the MP2605 to ensure that the device starts operating in a known state. The flow chart in Figure 5 describes the conditions and operation modes of the MP2605. CVC and CCC stand for “constant voltage charge” and “constant current charge”, respectively. POR VIN>VUVLO? After 32768 Cycles VBAT<2.6V? Termination YES TMR Start YES NO Battery Full Before 262144 Cycles? NO NO YES Reset TMR Turn Off Charger NO NO VBAT<4.0V? RCHG Set up Charging Set up? YES VCHG LED “ON” YES VBAT>4.18V VBAT<2.6V Which Charge Mode? Trickle Charge 2.6V<VBAT<4.18V C.V.C YES C.C.C NO VBAT >2.6V? ICHG<IBF Battery Full? NO YES TJ>130°C? YES VCHG LED “Off” Charger “Off” YES Soft-Off NO Short Circuit? TJ<120°C? NO YES NO NO VBAT>4.18V? YES Figure 5—Flow Chart of Operation MP2605 Rev. 0.94 1/25/2010 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2010 MPS. All Rights Reserved. 12 MP2605 – 28V, 1A LINEAR BATTERY CHARGER WITH TRICKLE CHARGE AND TIMER PACKAGE INFORMATION QFN10 (3mm x 3mm) NOTICE: The information in this document is subject to change without notice. Users should warrant and guarantee that third party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not assume any legal responsibility for any said applications. MP2605 Rev. 0.94 1/25/2010 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2010 MPS. All Rights Reserved. 13