Project Analog - February 2009 - (Page 11) nicd (nicKeL-cadmium) Li-ion (LiThium-ion) Li-Ion batteries have advantages in high energy density, low maintenance requirement, relatively low self discharge rate, and higher voltage per cell. (Table 1 and Table 2) The major drawbacks of Li-Ion batteries are higher initial cost and aging effect. Li-Ion batteries age over time regardless of the usage. Protection circuitry is required for Li-Ion battery to prevent over voltage during charge cycle and under voltage during discharge cycle. Li-PoLymer Li-Polymer batteries should be recognized as Li-Ion Polymer batteries. They are designed as an improved version of Li-Ion with flexible form-factors and very low profile. They are perfect for miniature applications, such as Bluetooth headsets or MP3 players. They have similar characteristics as Li-Ion and can be charged with the same algorithm. To view the full application note, click here. microchiP mcP73837/38 • High Accuracy Preset Voltage Regulation: ±0.5% • Four Voltage Regulation Options • Fully Integrated Linear Charge Management Controller: • Autonomous Power Source Selection • Constant Current (CC) / Constant Voltage (CV) Operation with Thermal Regulation • Selectable USB-Port Charge Current • Programmable AC-Adapter Charge Current • Two Charge Status Outputs • Power-Good Monitor: MCP73837 • Timer Enable: MCP73838 • Automatic Recharge: • Automatic End-of-Charge Control: – Selectable Charge Termination Current Ratio – Selectable Safety Timer Period • Preconditioning of Deeply Depleted Cells • Battery Cell Temperature Monitor • UVLO (Undervoltage Lockout) • Low-Dropout (LDO) Linear Regulator Mode Click here for more information on the MCP73837/38. NiCd batteries have the best charge/discharge cycles among rechargeable batteries (Table 1) and are good substitutes to Alkaline batteries because they employ the same basic voltage profile. NiCd batteries are required to be exercised periodically due to the memory effect. They are a very lowcost rechargeable solution because of the matured battery technology and simple charge algorithm. nimh (nicKeL-meTaL hydride) NiMH batteries are considered an improved version of NiCd batteries that provide higher energy density and environmentally friendly material. Both NiMH and NiCd batteries have high self discharge rates (Table 2) and are subject to memory effect. Although NiMH and NiCd batteries share similar charge algorithm, NiMH batteries require a more complex design due to the heat that NiMH batteries generate during charging and the difficult –ΔV/Δt detection. resources AN947: Power Management in Portable Applications: Charging Lithium-Ion/LithiumPolymer Batteries http://ww1. microchip.com/downloads/en/ AppNotes/00947a.pdf Battery Power Applications Design Guide http://ww1. microchip.com/downloads/en/ DeviceDoc/39610C.pdf AN971: USB Port-Powered Li-Ion/Li-Polymer Battery Charging http://ww1.microchip.com/downloads/en/ AppNotes/00971a.pdf MCP73831 Product Page http://www.microchip.com/ wwwproducts/Devices. aspx?dDocName=en024903 AN960: New Components and Design Methods Bring Intelligence to Battery Charger Applications http://ww1. microchip.com/downloads/en/ AppNotes/00960a.pdf Contents Viewpoint Selecting the Right dc/dc Converter Selecting the Right Battery System Understanding the Buck Switchmode Power Converter Analog news Microchip analog page Sample center microchipDIRECT Reference designs/ app notes Technical training 11 · PRojeCt ANAlog · VolUme 3 / NUmBeR 1 http://ww1.microchip.com/downloads/en/AppNotes/00947a.pdf http://ww1.microchip.com/downloads/en/AppNotes/00947a.pdf http://ww1.microchip.com/downloads/en/DeviceDoc/39610C.pdf http://ww1.microchip.com/downloads/en/DeviceDoc/39610C.pdf http://ww1.microchip.com/downloads/en/DeviceDoc/39610C.pdf http://ww1.microchip.com/downloads/en/AppNotes/00971a.pdf http://ww1.microchip.com/downloads/en/AppNotes/00971a.pdf http://ww1.microchip.com/downloads/en/AppNotes/00971a.pdf http://www.microchip.com http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en024903 http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=79&redirects=analog http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en024903 http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=79&redirects=analog http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en024903 http://sample.microchip.com/Default.aspx?testCookies=true http://www.microchipdirect.com/catalogselection.aspx?returnURL=default.aspx http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1469&filter1=function&redirects=appnotes http://ww1.microchip.com/downloads/en/AppNotes/00960a.pdf http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1469&filter1=function&redirects=appnotes http://ww1.microchip.com/downloads/en/DeviceDoc/22071a.pdf http://ww1.microchip.com/downloads/en/AppNotes/00960a.pdf http://ww1.microchip.com/downloads/en/AppNotes/01088a.pdf http://ww1.microchip.com/downloads/en/AppNotes/00960a.pdf http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1423
For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.