Features: Suitable for 1-1000AH 12V Lead-Acid Battery charger. The DD30CRTA is a PWM switch-mode battery charger controller for 12V lead-acid battery in a small package using few external components. The DD30CRTA is specially designed for charging 12V lead-acid battery with trickle charge, constant current charge, over-charge and float charge mode. In over-charge and float charge mode, the regulation voltage is internally set. The constant charge current is programmable with a single sense resistor. Deeply discharged batteries are automatically trickle charged at 17.5% of the programmed constant charge current until the cell voltage exceeds 75% of the regulation voltage in over-charge mode. The over-charge is terminated once the charging current drops to 38% of the constant charge current, then DD30CRTA will enter float charge mode. A new charge cycle automatically restarts if the battery voltage falls below 83.95% of the over-charge voltage in float-charge mode. DD30CRTA will automatically enter sleep mode when input voltage is lower than battery voltage. Other features include under voltage lockout and status indication, etc. The Regulation Voltage in Over Voltage Mode and Float Charge Mode: The regulation voltage VOC at BAT pin in over charge mode is set at 14.8V(Typical) with ±1.5% accuracy. In float charge mode, the regulation voltage VFLOAT at BAT pin is 91.57% of that in over charge mode, which is 13.55V(Typical). Trickle Charge Mode At the beginning of a charge cycle, if the battery voltage is below 75%xVOC, the charger goes into trickle charge mode with the charge current set at about 17.5% of the constant current. End-of-Over Charge Current: When the battery voltage approaches the over-charge voltage, the charger goes into the over charge mod