EVALUATION KIT AVAILABLE MAX1870A Step-Up/Step-Down Li+ Battery Charger General Description Benefits and Features The MAX1870A step-up/step-down multichemistry Highly Flexible Input Voltage Range Works with battery charger charges with battery voltages above Affordable AC Adapters and below the adapter voltage. This highly integrated Step-Up/Step-Down Control Scheme charger requires a minimum number of external com- Input Voltage from 8V to 28V ponents. The MAX1870A uses a proprietary step-up/ Analog Output Indicates Adapter Current step-down control scheme that provides effi- Accurately Charge Li+ or NiCd/NiMH Batteries cient charging. Analog inputs control charge current Battery Voltage from 0V to 17.6V and voltage, and can be programmed by the host or 0.5% Charge-Voltage Accuracy hardwired. 9% Charge-Current Accuracy The MAX1870A accurately charges two to four lithium- 8% Input Current-Limit Accuracy ion (Li+) series cells at greater than 4A. A program- Tune Design to Increase Safety and Efficiency mable input current limit is included, which avoids over- Programmable Maximum Battery Charge Current loading the AC adapter when supplying the load and Analog Inputs Control-Charge Current, Charge the battery charger simultaneously. This reduces the Voltage, and Input-Current Limit maximum adapter current, which reduces cost. The 32-Pin Thin QFN (5mm x 5mm) Package Saves MAX1870A provides analog outputs to monitor the Space while Supporting Step-Up and Step-Down current drawn from the AC adapter and charge current. Operation A digital output indicates the presence of an AC adapter. When the adapter is removed, the MAX1870A consumes less than 1A from the battery. Typical Operating Circuit The MAX1870A is available in a 32-pin thin QFN FROM WALL ADAPTER (5mm x 5mm) package and is specified over the SYSTEM LOAD -40C to +85C extended temperature range. The MAX1870A evaluation kit (MAX1870AEVKIT) is available CSSS CSSP to help reduce design time. DCIN CSSN VHP MAX1870A Applications VHN DHI P REF Notebook and Subnotebook Computers CLS CELLS Handheld Terminals N ASNS IINP DBST CSIP CSIN BATT REFIN BLKP SHDN ICTL VCTL LDO PGND DLOV GND Ordering Information appears at end of data sheet. 19-3243 Rev 3 8/15MAX1870A Step-Up/Step-Down Li+ Battery Charger Absolute Maximum Ratings DCIN, CSSP, CSSS, CSSN, LDO Current .......................................................................50mA VHP, VHN, DHI to GND .....................................-0.3V to +30V Continuous Power Dissipation (T = +70C) A VHP, DHI to VHN ...................................................-0.3V to +6V 32-Pin Thin QFN 5mm x 5mm BATT, CSIP, CSIN, BLKP to GND .........................-0.3V to +20V (derate 21mW/C above +70C) .....................................1.7W CSIP to CSIN, CSSP to CSSN, Operating Temperature Range CSSP to CSSS, PGND to GND .......................-0.3V to +0.3V MAX1870AETJ ............................................... -40C to +85C CCI, CCS, CCV, REF, IINP to GND ....... -0.3V to (V + 0.3V) Storage Temperature Range ............................ -60C to +150C LDO DBST to GND .......................................-0.3V to (V + 0.3V) Lead Temperature (soldering, 10s) ................................ +300C DLOV DLOV, VCTL, ICTL, REFIN, CELLS, CLS, LDO, ASNS, SHDN to GND .......................-0.3V to +6V 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. Package Information 32 TQFN Package Code T3255+4 Outline Number 21-0140 Land Pattern Number 90-0012 For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a +, , or - in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. Electrical Characteristics (Circuit of Figure 2, V = V = V = V = V = 18V, V = V = V = V = 12V, V = 3.0V, V = DCIN CSSP CSSN CSSS VHP BATT CSIP CSIN BLKP REFIN ICTL 0.75 x V , VCTL = LDO, CELLS = FLOAT, GND = PGND = 0, V = 5.4V, T = 0C to +85C, unless otherwise noted. Typical REFIN DLOV A values are at T = +25C.) A PARAMETER CONDITIONS MIN TYP MAX UNITS CHARGE-VOLTAGE REGULATION VCTL Range 0 3.6 V V = V (2 cells) -0.5 +0.5 VCTL LDO V = V (3 cells) -0.5 +0.5 VCTL LDO V = V (4 cells) -0.5 +0.5 VCTL LDO V = V (2 cells) -0.8 +0.8 VCTL REFIN Battery Regulation Voltage V = V (3 cells) -0.8 +0.8 % VCTL REFIN Accuracy V = V (4 cells) -0.8 +0.8 VCTL REFIN V = V / 20 (2 cells) -1.2 +1.2 VCTL REFIN V = V / 20 (3 cells) -1.2 +1.2 VCTL REFIN V = V / 20 (4 cells) -1.2 +1.2 VCTL REFIN VCTL Default Threshold VCTL rising 4.0 4.1 4.2 V 0 < V < V -1 +1 VCTL REFIN VCTL Input Bias Current DCIN = 0 V = V = 3.6V -1 +1 A , REFIN VCTL VCTL = DCIN = 0, V = 3.6V -1 +1 REFIN Maxim Integrated 2 www.maximintegrated.com