MCP73827 Single Cell Lithium-Ion Charge Management Controller with Mode Indicator and Charge Current Monitor Features Description Linear Charge Management Controller for Single The MCP73827 is a linear charge management con- Lithium-Ion Cells troller for use in space-limited, cost sensitive applica- tions. The MCP73827 combines high accuracy High Accuracy Preset Voltage Regulation: constant voltage, controlled current regulation, cell pre- + 1% (max) conditioning, and charge status indication in a space Two Preset Voltage Regulation Options: saving 8-pin MSOP package. The MCP73827 provides - 4.1V - MCP73827-4.1 a stand-alone charge management solution. - 4.2V - MCP73827-4.2 The MCP73827 charges the battery in three phases: Programmable Charge Current preconditioning, controlled current, and constant volt- Automatic Cell Preconditioning of Deeply age. If the battery voltage is below the internal low-volt- Depleted Cells, Minimizing Heat Dissipation Dur- age threshold, the battery is preconditioned with a ing Initial Charge Cycle foldback current. The preconditioning phase protects Charge Status Output for LED Drive or Microcon- the lithium-ion cell and minimizes heat dissipation. troller Interface Following the preconditioning phase, the MCP73827 Charge Current Monitor Output enters the controlled current phase. The MCP73827 Automatic Power-Down when Input Power allows for design flexibility with a programmable charge Removed current set by an external sense resistor. The charge current is ramped up, based on the cell voltage, from Temperature Range: -20C to +85C the foldback current to the peak charge current estab- Packaging: 8-Pin MSOP lished by the sense resistor. This phase is maintained until the battery reaches the charge-regulation voltage. Applications Then, the MCP73827 enters the final phase, constant Single Cell Lithium-Ion Battery Chargers voltage. The accuracy of the voltage regulation is better Personal Data Assistants 1% over the entire operating temperature range than + Cellular Telephones and supply voltage range. The MCP73827-4.1 is preset Hand Held Instruments to a regulation voltage of 4.1V, while the MCP73827-4.2 is preset to 4.2V. The charge status Cradle Chargers output, MODE, indicates when the charge cycle has Digital Cameras transitioned to constant voltage mode. The charge cycle can be terminated by a timer that is started when Typical Application Circuit the MODE pin goes to a logic High or by monitoring the 500 mA Lithium-Ion Battery Charger charge current monitor output, I , for a minimum MON MA2Q705 NDS8434 current. 100 m V IN 5V The MCP73827 operates with an input voltage range + Single 10 F 332 Lithium-Ion 7 6 from 4.5V to 5.5V. The MCP73827 is fully specified - Cell V V SNS DRV over the ambient temperature range of -20C to +85C. 8 5 V V IN BAT 10 F 100 k Package Type 12 SHDN GND 3 4 I MSOP MODE MON SHDN V 1 8 IN MCP73827 GND 7 V 2 SNS MCP73827 V MODE 6 3 DRV I V 4 5 MON BAT 2007 Microchip Technology Inc. DS21704B-page 1 + MCP73827 Functional Block Diagram DS21704B-page 2 2007 Microchip Technology Inc. + I MON 100 k 138 k CHARGE CURRENT MONITOR AMPLIFIER MODE + - V IN MODE 1.1 k V IN COMPARATOR V DRV V SNS + CHARGE + CURRENT AMPLIFIER V BAT 12 k V 352.5 k REF (NOTE 1) 500 k 75 k VOLTAGE CONTROL CHARGE CURRENT CONTROL AMPLIFIER AMPLIFIER V (1.2V) REF SHUTDOWN, SHDN REFERENCE GENERATOR V IN V REF 112.5 k + 0.3V CLAMP 75 k 37.5 k GND CHARGE CURRENT FOLDBACK AMPLIFIER NOTE 1: Value = 340.5K for MCP73827-4.1 Value = 352.5K for MCP73827-4.2