MP26121DQ-LF-P

MP26121 The Future of Analog IC Technology 28V, 1A Li + Linear Battery Charger with 10% Battery-Full Threshold and Flexible NTC Interface DESCRIPTION FEATURES The MP26121 is a linear, high-performance single cell Li-Ion/Li-Polymer battery charger. By integrating high voltage input protection into the charger IC, the MP26121 can tolerate an input surge up to +28V. • • • • • • • • • • • • 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. For guaranteed safe operation, the MP26121 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. The MP26121 is available in 10-pin 3mm x 3mm QFN packages. Interfaces to Many NTC Resistor Values Proprietary VIN Surge Protection up to 28V Programmable Charge Current up to 1A 1% Voltage Accuracy 10% Battery-Full Threshold No Reverse Blocking Diode Required Intelligent Thermal Management Trickle Charge 7V Input OVP Auto Recharge Charge-Timer Fault and Charge Status Indicators APPLICATIONS • • • • • 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. TYPICAL APPLICATION MP26121 Rev. 0.9 9/15/2008 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 MPS. All Rights Reserved. 1 MP26121 – +28V, 1A Li+ Linear Batt Charger with Flexible NTC Interface ABSOLUTE MAXIMUM RATINGS (1) PACKAGE REFERENCE 1 10 2 9 3 8 4 7 5 6 IN to GND ....................................... –5V to +28V ACOK and CHG Maximum Sink Current........20mA All Other Pins to GND..................-0.3V to +6.5V Junction Temperature...............................140°C Lead Temperature ....................................260°C Storage Temperature ..............–65°C to +150°C Recommended Operating Conditions Nominal Supply Voltage VIN............ 3.5V to 6.5V Operating Temperature .............–40°C to +85°C Thermal Resistance Part Number* MP26121DQ * Package QFN10 (3mm x 3mm) (2) Temperature –40°C to +85°C For Tape & Reel, add suffix –Z (e.g. MP26121DQ–Z) For RoHS compliant packaging, add suffix –LF (e.g. MP26121DQ–LF–Z) (3) θJA θJC 3x3 QFN10 ............................. 50 ...... 12... °C/W Notes: 1) Exceeding these ratings may damage the device. 2) The device is not guaranteed to function outside of its operating conditions. 3) Measured on approximately 1” square of 1 oz copper. The exposed pad must be Soldered to a ground plane ELECTRICAL CHARACTERISTICS VIN = 5V, VSHDN = 0V, TA = +25°C, unless otherwise noted. Parameter Symbol Condition Supply Current ISUPPLY Battery Voltage Regulation Constant Current Regulation VBATT 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) 7.5 5 2.45 10 10 2.6 100 12.5 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 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 MP26121 Rev. 0.9 9/15/2008 IBF VIN = 5V, VBATT = 2.3V VZ OVP 8.2 VIN Rising 6.7 7 400 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 MPS. All Rights Reserved. V 7.3 V mV 2 MP26121 – +28V, 1A Li+ Linear Batt Charger with Flexible NTC Interface ELECTRICAL CHARACTERISTICS (continued) VIN = 5V, VSHDN = 0V, TA = +25°C, unless otherwise noted. Parameter Symbol Condition SHDN Trip Threshold High Min Typ 2.6 0.4 ISHDN VSHDN=3V CHG , ACOK Sink Current Pin Voltage = 0.4V Battery Reverse Current to BATT Pin SHDN = Low and Input = Floating or 0V Dropout Voltage VIN-VBATT Die Temperature Limit Recharge Voltage Threshold 6 VRECHARGE VNTC_UP 0.25 VNTC_LOW V 120 135 °C 3.9 4.0 4.1 V 100 mV 2.735 V 75 mV 1.197 V 20 mV CTMR = 2.2uF 5 Hz VIN=5.00V, NTC pin voltage rising VIN=5.00V, NTC pin voltage falling NTC Lower Trip Hysteresis Oscillation Freq µA 105 NTC Upper Trip Hysteresis NTC Lower Threshold mA 1 Recharge Voltage Hysteresis NTC Upper Threshold V µA 8 VBATT = 3.8V, RCHG = 6kΩ. Current drop 10% Units V SHDN Trip Threshold Low SHDN Pull up Current Max TMR Pin Source Current ITMR1 VTMR=0.1V 20 µA TMR Pin Sink Current ITMR2 VTMR=1.5V 20 µA From Trickle to 90% Full Current, CSS=0.1µF 80 mS Soft Start Time Notes: 4) ICHG is the target preprogrammed charge current (Die temperature below 110°C). MP26121 Rev. 0.9 9/15/2008 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 MPS. All Rights Reserved. 3 MP26121 – +28V, 1A Li+ Linear Batt Charger with Flexible NTC Interface PIN FUNCTIONS Pin # Name 1 VIN 2 ACOK 3 CHG 4 TMR 5 6 7 8 9 10 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. SS Soft-Start. Connect a capacitor to ground to set the soft-start time. Constant Charge Current Program Pin. Connect this pin to an external resistor to ISET program the charging current in CC Mode. Negative Temperature Coefficient (NTC) Thermistor Pin. Connect a resistor RT1 from this pin to VIN pin and a resistor RT2 from this pin to GND in parallel with the NTC NTC resistor (within the battery pack). If NTC function is not used, apply RT2=1/2 RT1. Do not leave this pin floating. BATT Charger Output. BLOCK DIAGRAM Figure 1—Functional Block Diagram MP26121 Rev. 0.9 9/15/2008 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 MPS. All Rights Reserved. 4 MP26121 – +28V, 1A Li+ Linear Batt Charger with Flexible NTC Interface TYPICAL PERFORMANCE CURVES CIN = 4.7µF, COUT = 2.2µF, CSS = 0.1µF, VIN = 5V, TA = +25°C, unless otherwise noted. MP26121 Rev. 0.9 9/15/2008 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 MPS. All Rights Reserved. 5 MP26121 – +28V, 1A Li+ Linear Batt Charger with Flexible NTC Interface TYPICAL PERFORMANCE CURVES (continued) CIN = 4.7µF, COUT = 2.2µF, CSS = 0.1µF, VIN = 5V, TA = +25°C, unless otherwise noted. MP26121 Rev. 0.9 9/15/2008 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 MPS. All Rights Reserved. 6 MP26121 – +28V, 1A Li+ Linear Batt Charger with Flexible NTC Interface OPERATION Input Voltage Range The MP26121 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 CV) Figure 2 shows the typical charging profile for the MP26121. For a fully depleted battery with a terminal voltage lower than 2.6V, the MP26121 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, CHG becomes high impedance, indicating a battery fault. 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 10% 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 10% 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 MP26121 Rev. 0.9 9/15/2008 battery full threshold is internally programmed to be 10% of the ICHG. When the charge current reaches this threshold, the charger IC will be automatically turned off. Figure 2—MP26121 Typical Charging Profile Automatic Recharge When VBATT drops to 4.0V, the charger will automatically restart the charge cycle until the 10% 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 MP26121 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. 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. © 2008 MPS. All Rights Reserved. ICHG (mA) 1000 900 800 700 600 500 400 300 200 100 7 MP26121 – +28V, 1A Li+ Linear Batt Charger with Flexible NTC Interface 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. Figure 3—Charge Current vs. 1/RCHG Resistance The recommended resistance for programming the charge current is 2.3kΩ