its a chip made by On semiconductor and theres still a few left at mouser.
i originally planned on just modifying the existing charger chips inside a cheap charger, but i then figured for $2 i could replace it with a much better solution. im getting a few external chargers that are molded to my cell phone battery, (touch pro 2), and ill remove the internal 350ma charger and replace it with this circuit which is 1000ma.
Features
• Integrated Voltage and Current Regulation
• No External MOSFET, Sense Resistor or Blocking Diode Required
• Charge Current Thermal Foldback
• Integrated Pre−charge Current for Conditioning Deeply Discharged
Battery
• Integrated End−of−Charge (EOC) Detection
• 1% Voltage Regulation
• 4.2 V or 4.242 V Regulated Output Voltage
• Regulation Maintained without a Battery Present
• Programmable Full Charge Current 300 − 1000 mA
• Open−Drain Charger Status and Fault Alert Flags
• 2.8 V Output for AC Present Indication and Powering Charging
Subsystems
• Minimum Input Voltage of 2.4 V Allows Use of Current Limited
Adapters
• Automatically Recharging if Battery Voltage Drops after Charging
Cycle is Completed
• Low Profile 3x3 mm DFN Package
• Pb−Free Packages are Available
http://www.onsemi.com/pub_link/Collateral/NCP1835-D.PDF
as you can see it doesn't take many external parts to make it work, and i guess you can hook it to a microprocessor too for more control. i just want something simple, and after much searching through datasheets, i think this one is the best value.
love to hear any opinions... but the only real question i have is what specific capacitor would be best for the timing circuit?
i originally planned on just modifying the existing charger chips inside a cheap charger, but i then figured for $2 i could replace it with a much better solution. im getting a few external chargers that are molded to my cell phone battery, (touch pro 2), and ill remove the internal 350ma charger and replace it with this circuit which is 1000ma.
Features
• Integrated Voltage and Current Regulation
• No External MOSFET, Sense Resistor or Blocking Diode Required
• Charge Current Thermal Foldback
• Integrated Pre−charge Current for Conditioning Deeply Discharged
Battery
• Integrated End−of−Charge (EOC) Detection
• 1% Voltage Regulation
• 4.2 V or 4.242 V Regulated Output Voltage
• Regulation Maintained without a Battery Present
• Programmable Full Charge Current 300 − 1000 mA
• Open−Drain Charger Status and Fault Alert Flags
• 2.8 V Output for AC Present Indication and Powering Charging
Subsystems
• Minimum Input Voltage of 2.4 V Allows Use of Current Limited
Adapters
• Automatically Recharging if Battery Voltage Drops after Charging
Cycle is Completed
• Low Profile 3x3 mm DFN Package
• Pb−Free Packages are Available
http://www.onsemi.com/pub_link/Collateral/NCP1835-D.PDF
as you can see it doesn't take many external parts to make it work, and i guess you can hook it to a microprocessor too for more control. i just want something simple, and after much searching through datasheets, i think this one is the best value.
love to hear any opinions... but the only real question i have is what specific capacitor would be best for the timing circuit?