EVALUATION KIT AVAILABLE Multichemistry Battery Chargers with MAX1909/MAX8725 Automatic System Power Selector General Description Benefits and Features Precise Measurement Improves Safety and The MAX1909/MAX8725 highly integrated control ICs Performance simplify construction of accurate and efficient multi- 0.5% Accurate Charge Voltage (0C to +85C) chemistry battery chargers. The MAX1909/MAX8725 3% Accurate Input Current Limiting use analog inputs to control charge current and volt- 5% Accurate Charge Current age, and can be programmed by a host microcontroller Analog Inputs Control Charge Current and Charge (C) or hardwired. High efficiency is achieved through Voltage use of buck topology with synchronous rectification. Charge Any Battery Chemistry: Li+, NiCd, NiMH, The maximum current drawn from the AC adapter is pro- Lead Acid, etc. grammable to avoid overloading the AC adapter when Up to 17.65V (max) Battery Voltage supplying the load and the battery charger simultane- Maximum 28V Input Voltage ously. The MAX1909/MAX8725 provide a digital output Programmable Charge Current > 4A that indicates the presence of an AC adapter, and an Intelligent AC Adapter Interface Makes Design Easier analog output that monitors the current drawn from the Automatic System Power/Source Selection AC adapter. Based on the presence or absence of the Analog Monitoring of Current Drawn from AC Input AC adapter, the MAX1909/MAX8725 automatically Source select the appropriate source for supplying power to the Digital Output Indicates AC Adapter Presence system by controlling two external p-channel MOSFETs. Greater than 95% Efficiency Extends Battery Life Under system control, the MAX1909/MAX8725 allow the battery to undergo a relearning or conditioning cycle in which the battery is completely discharged through the Ordering Information system load and then recharged. PART TEMP RANGE PIN-PACKAGE The MAX1909 includes a conditioning charge feature MAX1909ETI -40C to +85C 28 Thin QFN while the MAX8725 does not. The MAX1909/MAX8725 MAX1909ETI+ -40C to +85C 28 Thin QFN are available in space-saving 28-pin, 5mm 5mm thin QFN packages and operate over the extended -40C to MAX8725ETI -40C to +85C 28 Thin QFN +85C temperature range. The MAX1909/MAX8725 are MAX8725ETI+ -40C to +85C 28 Thin QFN now available in lead-free packages. +Denotes a lead(Pb)-free/RoHS-compliant package. Applications Notebook and Subnotebook Computers Minimum Operating Circuit Hand-Held Data Terminals P3 TO 0.01 EXTERNAL LOAD AC ADAPTER: INPUT Pin Configuration SRC CSSP CSSN TOP VIEW PDS DHIV SRC PDL P2 DCIN 28 27 26 25 24 23 22 MAX1909 MAX8725 LDO VCTL ICTL LDO DCIN 1 21 DLOV MODE DLOV LDO 2 20 DLO ACIN P1 LDO IINP IINP ACIN 3 19 PGND REF DHI CLS MAX1909 REF 4 18 CSIP ACOK MAX8725 LDO GND/PKPRES 5 17 CSIN N1 DLO 10H PGND ACOK 6 16 BATT PKPRES MAX8725 ONLY CSIP MODE 7 15 GND 0.015 8 9 10 11 12 13 14 CCV CSIN CCI BATT CCS GND REF THIN QFN Functional Diagrams appear at end of data sheet. 19-2805 Rev 3 5/15 IINP PDL CLS PDS ICTL CSSP VCTL CSSN CCI SRC CCV DHI CCS DHIVMultichemistry Battery Chargers with MAX1909/MAX8725 Automatic System Power Selector Absolute Maximum Ratings DCIN, CSSP, CSSN, SRC, ACOK to GND..............-0.3V to +30V DLOV to LDO.........................................................-0.3V to +0.3V DHIV ........................................................SRC + 0.3, SRC - 6V DLO to PGND..........................................-0.3V to (DLOV + 0.3V) DHI, PDL, PDS to GND ...............................-0.3V to (V + 0.3) LDO Short-Circuit Current...................................................50mA SRC BATT, CSIP, CSIN to GND .....................................-0.3V to +20V Continuous Power Dissipation (T = +70C) A CSIP to CSIN or CSSP to CSSN or PGND to GND ...-0.3V to +0.3V 28-Pin TQFN (derate 20.8mW/C above +70C) .......1666mW CCI, CCS, CCV, DLO, IINP, REF, Operating Temperature Range ...........................-40C to +85C ACIN to GND ........................................-0.3V to (V + 0.3V) Junction Temperature......................................................+150C LDO DLOV, VCTL, ICTL, MODE, CLS, LDO, Storage Temperature Range .............................-60C to +150C PKPRES to GND...................................................-0.3V to +6V Lead Temperature (soldering, 10s) .................................+300C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Electrical Characteristics (Circuit of Figure 1, V = V = V = 18V, V = V = V = 12V, V = V = 1.8V, MODE = float, ACIN = 0, CLS = DCIN CSSP CSSN BATT CSIP CSIN VCTL ICTL REF, GND = PGND = 0, PKPRES = GND, LDO = DLOV, T = 0C to +85C, unless otherwise noted. Typical values are at T = +25C.) A A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS CHARGE VOLTAGE REGULATION VCTL Range 0 3.6 V V = 3.6V (3 or 4 cells) VCTL -0.8 +0.8 not including VCTL resistor tolerances V = 3.6V/20 (3 or 4 cells) not including VCTL -0.8 +0.8 VCTL resistor tolerances Battery Regulation Voltage % Accuracy V = 3.6V (3 or 4 cells) including VCTL VCTL -1.0 +1.0 resistor tolerances of 1% V = V (3 or 4 cells, default VCTL LDO -0.5 +0.5 threshold of 4.2V/cell) V Default Threshold V rising 4.1 4.3 V VCTL VCTL V = 3V 0 2.5 VCTL VCTL Input Bias Current A V = 0, V = 5V 0 12 DCIN VCTL CHARGE-CURRENT REGULATION MAX1909 0 3.6 ICTL Range V MAX8725 0 3.2 CSIP-to-CSIN Full-Scale Current- 69.37 75.00 80.63 mV Sense Voltage MAX1909: V = 3.6V (not including ICTL ICTL -7.5 +7.5 resistor tolerances) MAX8725: V = 3.2V (not including ICTL ICTL -5 +5 resistor tolerances) MAX1909: V = 3.6V x 0.5, MAX8725: ICTL Charge-Current Accuracy V = 3.2V x 0.5 (not including ICTL -5 +5 % ICTL resistor tolerances) MAX1909: V = 0.9V (not including ICTL ICTL -7.5 +7.5 resistor tolerances) MAX8725: V = 0.18V (not including ICTL -30 +30 ICTL resistor tolerances) www.maximintegrated.com Maxim Integrated 2