MAX846A 19-1121 Rev 0 9/96 Cost-Saving Multichemistry Battery-Charger System General Description Features The MAX846A is a cost-saving multichemistry battery- Multichemistry Charger System (Li-Ion, NiMH, NiCd) charger system that comes in a space-saving 16-pin Independent Voltage and Current Loops QSOP. This integrated system allows different battery 0.5% Internal Reference for Li-Ion Cells chemistries (Li-Ion, NiMH or NiCd cells) to be charged Lowers Cost: using one circuit. Stands Alone or Uses Low-Cost C In its simplest application, the MAX846A is a stand- alone, current-limited float voltage source that charges Built-In 1% Linear Regulator Powers C Li-Ion cells. It can also be paired up with a low-cost Linear Regulator Provides Reference to C ADCs microcontroller (C) to build a universal charger capa- Built-In C Reset ble of charging Li-Ion, NiMH, and NiCd cells. Controls Low-Cost External PNP Transistor or An internal 0.5%-accurate reference allows safe charg- P-Channel MOSFET ing of Li-Ion cells that require tight voltage accuracy. The voltage- and current-regulation loops used to con- Space-Saving 16-Pin QSOP trol a low-cost external PNP transistor (or P-channel Charging-Current-Monitor Output MOSFET) are independent of each other, allowing more <1A Battery Drain when Off flexibility in the charging algorithms. The MAX846A has a built-in 1%, 3.3V, 20mA linear regu- lator capable of powering the C and providing a refer- ence for the Cs analog-to-digital converters. An Ordering Information on-board reset notifies the controller upon any unex- pected loss of power. The C can be inexpensive, since PART TEMP. RANGE PIN-PACKAGE its only functions are to monitor the voltage and current MAX846AC/D 0C to +70C Dice* and to change the charging algorithms. MAX846AEEE -40C to +85C 16 QSOP Applications *Dice are tested at T = +25C only. 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A Li-Ion Battery Packs Desktop Cradle Chargers Li-Ion/NiMH/NiCd Multichemistry Battery Typical Operating Circuit Chargers Cellular Phones 3.5V TO Notebook Computers 20V Hand-Held Instruments Pin Configuration DRV TOP VIEW CS- BATT Li-ION DCIN 1 16 DRV CS+ BATTERY VL 2 PGND 15 DCIN CCI 3 14 CS- MAX846A ISET VL GND 4 MAX846A CS+ 13 CELL2 CCV 5 12 BATT CCV VSET 6 11 ON GND CCI ISET 7 10 CELL2 PGND PWROK OFFV 9 8 PWROK ON QSOP Maxim Integrated Products 1 For free samples & the latest literature: Cost-Saving Multichemistry Battery-Charger System ABSOLUTE MAXIMUM RATINGS DCIN, DRV, CS+, CS-, BATT to GND........................-0.3V, +21V Continuous Power Dissipation (T = +70C) A PGND to GND.....................................................................0.3V QSOP (derate 8.3mW/C above +70C)........................667mW VL to GND......................................................................-0.3V, 7V Operating Temperature Range I ................................................................................10mA MAX846AEEE ....................................................-40C to +85C PWROK PWROK, ISET, CCI, CCV, OFFV, VSET, Junction Temperature......................................................+150C CELL2, ON to GND ............................................-0.3V, VL + 0.3V Storage Temperature Range .............................-65C to +160C CS+ to CS-..........................................................................0.3V Lead Temperature (soldering, 10sec) .............................+300C VL Short to GND.........................................................Continuous I ...................................................................................100mA DRV 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 (V = 10V, ON = VL, I = I = 0mA, V - = V = 10V, V = 4.5V, V = V = 0V, T = 0C to +85C, unless DCIN VL VSET CS CS+ BATT OFFV CELL2 A otherwise noted. Typical values are at T = +25C.) A PARAMETER CONDITIONS MIN TYP MAX UNITS VL REGULATOR DCIN Supply Current V = 20V, I = I = 0mA 5 mA DCIN DRV VL Operating Range 3.7 20.0 V Output Voltage 0mA < I < 20mA, 3.7V < V < 20V 3.267 3.305 3.333 V VL DCIN Short-Circuit Current Limit VL = GND 50 mA PWROK Trip Level Rising VL edge, 2% hysteresis 2.9 3.0 3.1 V VL Undervoltage-Lockout Level 2.5 2.9 V REFERENCE Output Voltage Measured at VSET, I = 0mA, V = 0V -0.5% 1.650 +0.5% V VSET ON Output Resistance -2% 20 +2% k CURRENT-SENSE AMPLIFIER Transconductance V = 1.7V, V - V = 165mV 0.95 1 1.05 mA/V ISET CS+ CS- Output Offset Current V = 4V 3 m A CS+ Input Common-Mode Range Measured at V , V - V = 165mV 2.1 20.0 V CS+ CS- CS- V = V = 2.1V, CS- ISET Maximum Differential Input Voltage 225 mV CSA transconductance >0.9mA/V When V is less than this voltage, DRV is CS- CS- Lockout Voltage 1.9 2.1 V disabled. CS+, CS- Input Current V = 20V, V -V = 165mV 250 m A CS+ CS+ CS- m A CS+, CS- Off Input Current DCIN = VL = ON = GND 0.01 10 2 MAX846A