MCP73828 M Single Cell Lithium-Ion Charge Management Controller with Charge Complete Indicator and Temperature Monitor Features Description Linear Charge Management Controller for Single The MCP73828 is a linear charge management con- Lithium-Ion Cells troller for use in space-limited, cost sensitive applica- tions. The MCP73828 combines high accuracy High Accuracy Preset Voltage Regulation: constant voltage, controlled current regulation, cell pre- +1% (max) conditioning, cell temperature monitoring, and charge Two Preset Voltage Regulation Options: complete indication in a space saving 8-pin MSOP - 4.1V - MCP73828-4.1 package. The MCP73828 provides a stand-alone - 4.2V - MCP73828-4.2 charge management solution. Programmable Charge Current The MCP73828 charges the battery in three phases: Automatic Cell Preconditioning of Deeply preconditioning, controlled current, and constant volt- Depleted Cells, Minimizing Heat Dissipation age. If the battery voltage is below the internal low-volt- During Initial Charge Cycle age threshold, the battery is preconditioned with a Charge Complete Output CD10 for LED or foldback current. The preconditioning phase protects Microcontroller Interface the lithium-ion cell and minimizes heat dissipation. Continuous Temperature Monitoring Following the preconditioning phase, the MCP73828 Automatic Power-Down when Input Power enters the controlled current phase. The MCP73828 Removed allows for design flexibility with a programmable charge current set by an external sense resistor. The charge Temperature Range: -20C to +85C current is ramped up, based on the cell voltage, from Packaging: 8-Pin MSOP the foldback current to the peak charge current estab- lished by the sense resistor. This phase is maintained Applications until the battery reaches the charge-regulation voltage. Single Cell Lithium-Ion Battery Chargers Then, the MCP73828 enters the final phase, constant Personal Data Assistants voltage. The accuracy of the voltage regulation is better Cellular Telephones than 1% over the entire operating temperature range Hand Held Instruments and supply voltage range. The MCP73828-4.1 is preset to a regulation voltage of 4.1V, while the MCP73828- Cradle Chargers 4.2 is preset to 4.2V. The charge complete output, Digital Cameras CD10, indicates when the charge current has dimin- ished to approximately 10% of the peak charge current Typical Application Circuit established by the sense resistor. The MCP73828 operates with an input voltage range 500 mA Lithium-Ion Battery Charger from 4.5V to 5.5V. The MCP73828 is fully specified NDS8434 MA2Q705 over the ambient temperature range of -20C to +85C. 100 m Thermistor V IN 5V + Single 332 10 F 7 6 - Lithium-Ion Package Type V V Cell SNS DRV 8 5 V V IN BAT 10 F MSOP 100 k 12 SHDN GND SHDN V 1 8 IN 4 3 THERM CD10 GND 7 V 2 SNS MCP73828 MCP73828 V THERM 3 6 DRV CD10 V 4 5 BAT 2002 Microchip Technology Inc. DS21706A-page 1- + - + + MCP73828 Functional Block Diagram DS21706A-page 2 2002 Microchip Technology Inc. CD10 + + 140 mV - CHARGE COMPLETE V 100 k 156 k IN COMPARATOR CHARGE COMPLETE 1.1 k V IN AMPLIFIER V DRV V SNS + CHARGE + CURRENT AMPLIFIER V BAT 12 k V 352.5 k REF (NOTE 1) 500 k 75 k CHARGE CURRENT VOLTAGE CONTROL CONTROL AMPLIFIER AMPLIFIER VREF (1.2V) SHUTDOWN, SHDN REFERENCE GENERATOR V IN 75 k V REF GND 112.5 k + V V REF IN 0.3V CLAMP 37.5 k I THERM 67 k 25 mA 839 mV CHARGE CURRENT FOLDBACK AMPLIFIER THERM 130 k 140 mV 5k 113 mV 21 k NOTE 1: Value = 340.5K For MCP73828-4.1 THERMISTOR VOLTAGE COMPARATORS Value = 352.5K For MCP73828-4.2