MP2608DQ-LF-Z

MP2608 28V, 1A Dual Input Linear Battery Charger With Timer The Future of Analog IC Technology DESCRIPTION FEATURES The MP2608 is a dual-input, linear, high-performance low-cost single cell Li-Ion or Li-Polymer battery charger. It accepts two power inputs, one from a USB (Universal BUS) port and the other from an AC adapter. By integrating high voltage input protection into the charger IC, the MP2608 can tolerate an input surge up to 28V. Due to the protection inputs function, low-cost, large output tolerance adapters can be used safely. • • • • • • • • • • • • • • • The device features constant current (CC) and constant voltage (CV) charging modes with programmable charge currents (100mA to 1.0A), current blocking and trickle charge. The charge current for adapter input can be programmed by an external resistor, while the charge current for USB input is pre-set at 450mA.The device also provides charge status and fault indications to the system. Complete Solution for Charging Single-Cell Lion-Ion Battery Input Surge Up to 28V Adapter and USB Input Programmable Charge Current: 100mA to 1.0A Pre-set USB Charge Current: 450mA Proprietary Constant Voltage Auto Recharge Proprietary Over-Voltage Protection 0.75% VBATT Accuracy over Temperature CC-> CV) Figure 2 below shows the typical charging profile for the MP2608. For a fully depleted battery with a terminal voltage lower than 2.6V, the MP2608 will start with the trickle charge (preconditioning) at 10% of the programmed full charge current. After the battery voltage reaches 2.6V, the charger begins charging at the constant current of the programmed value (ICHG) and the charge timer starts counting down. 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 timer is time off. The charge timer is to protect the system from charging a dead battery for excessive long time. VIN VCH VBATT VMIN ISET IBATT 10% of ISET POWER DISSIPATION Charge Trickle Start Charging CC Mode CV Mode Charge End Timer Figure 2—MP2608 Typical Charging Profile Charge Termination and Auto-Recharge At any time when VBATT is 50mV higher than the trimmed charge target, the MP2608 reduces its charge current to 0µA. This ensures the safety of the battery. Also, the CV control loop always monitors the battery voltage such that it will automatically recharge the battery when it is depleted below the target level. Upon VBATT drops to 4.0V, the charger will automatically restart the charge cycle until the end of the timeout. When the input adapter is unplugged, there is only 1µA leakage current from battery drawn by the MP2608. Programming of Charge Current and Battery Full Current The Charge Current (ICHG) of Adaptor input can be programmed from 0.1A to 1A by a resistor (RCHG) connecting from the ICHG pin to GND. The relationship of the charge current and the programming resistance is established by the following table and graph. The recommended resistance for programming the charge current is TBD.The battery full charge current threshold (IBF)is programmed by connecting a resistor RBF from the IBF pin to GND: IBF=1AX1.7kΩ/RBF When the USB is selected as the power source, the charge current is fixed at a pre-set value 450mA, which is a typical value of USB current. MP2608 Rev. 0.9 8/29/2008 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 MPS. All Rights Reserved. 9 MP2608- 28V, 1A DUAL INPUT LINEAR BATTERY CHARGER WITH TIMER Table 1—RCHG and ICHG Relationship RCHG (kΩ) ICHG (mA) TBD TBD Figure 3—Charge Current vs. 1/RPGM Resistance VIN Charge Status and Fault Indication The open drain pin STATUS is used to indicate charging status. While battery is being charged, the STATUS pin is pulled low, when the battery full condition is reached or any other condition prevents the charger from charging, the STATUS pin will become a floating. STATUS is then latched till a new charge cycle is started. Upon a time-out fault event happen, the FAULT pin is pulled low. When the VBATT is lower than 2.6V for 1/8th of timeout period or the charging can not reach EOC status before the timeout happens, this fault status is latched, the charging is suspended, and the FAULT pin is pulled low. To clear this fault, either the VIN or VUSB should be recycled. One time-out period is equivalent to 215 oscillator clock cycles. With a 1µF capacitor on the TMR pin, it takes 3.64 hours. The Power On and recharge cycle are illustrated in Figure 4. POR Threshold STATUS FAULT 15 Cycles to 1/8 TIMEOUT VRECHARGE VBATT 2.6V VMIN 15 Cycles IMIN ICHARGE t0 t1 t2 t3 t4 t5 t6 t7 Figure 4—MP2608 Typical Re-Charging Waveforms MP2608 Rev. 0.9 8/29/2008 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 MPS. All Rights Reserved. 10 MP2608- 28V, 1A DUAL INPUT LINEAR BATTERY CHARGER WITH TIMER STATE DIAGRAM . POR or VIN or low STOP Timeout Fault VIN POR and Battery Inserted and VBAT VIN and EN high VBATT VTRK for 1/8th TIMEOUT Temp fault Temp Fault Temp Fault Removed Trickle Charge STATUS VBATT VTRK before 1/8th TIMEOUT Fast Charge FAULT FAULT Temp Fault VBATT TEMP fault removed VRECH (VBATT V IBATT IMIN) End of Charge Termination TIMEOUT Temp Fault TEMP fault TEMP fault Figure 5—MP2608 State Diagram MP2608 Rev. 0.9 8/29/2008 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 MPS. All Rights Reserved. 11 MP2608- 28V, 1A DUAL INPUT LINEAR BATTERY CHARGER WITH TIMER PACKAGE INFORMATION QFN10 (3mm x 3mm) 2.90 3.10 0.30 0.50 PIN 1 ID MARKING 0.18 0.30 2.90 3.10 PIN 1 ID INDEX AREA 1.45 1.75 PIN 1 ID SEE DETAIL A 10 1 2.25 2.55 0.50 BSC 5 6 TOP VIEW BOTTOM VIEW PIN 1 ID OPTION A R0.20 TYP. PIN 1 ID OPTION B R0.20 TYP. 0.80 1.00 0.20 REF 0.00 0.05 SIDE VIEW DETAIL A NOTE: 2.90 0.70 1) ALL DIMENSIONS ARE IN MILLIMETERS. 2) EXPOSED PADDLE SIZE DOES NOT INCLUDE MOLD FLASH. 3) LEAD COPLANARITY SHALL BE 0.10 MILLIMETER MAX. 4) DRAWING CONFORMS TO JEDEC MO-229, VARIATION VEED-5. 5) DRAWING IS NOT TO SCALE. 1.70 0.25 2.50 0.50 RECOMMENDED LAND PATTERN 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. MP2608 Rev. 0.9 8/29/2008 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 MPS. All Rights Reserved. 12