CXLB73253 is a PFM boost type dual cell lithium battery charging control integrated circuit that operates between 2.75V and 6.5V. CXLB73253 adopts constant current and quasi constant voltage mode (CVTM) for battery charging management. It integrates a reference voltage source, an inductor current detection unit, a battery voltage detection circuit, and an on-chip field-effect transistor drive circuit. It has the advantages of few external components and simple circuit. When the input power is turned on, CXLB73253 enters the charging state, controls the external N-channel MOSFET to conduct, and the inductor current increases. When it reaches the upper limit set by the external current detection resistor, the external N-channel MOSFET is turned off, the inductor current decreases, and the energy in the inductor is transferred to the battery. When the inductor current drops to the lower limit set by the external current detection resistor, the off chip N-channel MOSFET conducts again, and so on. When the BAT pin voltage reaches the internally set 8.4V (typical value) for the first time, CXLB73253 enters quasi constant voltage charging mode to charge the battery with a smaller current. In quasi constant voltage mode, when the BAT pin voltage reaches 8.4V, the charging process ends and the off chip N-channel MOSFET remains in the off state. When the BAT pin voltage drops to the recharge threshold, CXLB73253 enters the charging state again. The maximum operating frequency of CXLB73253 can reach 1MHz. When the battery voltage is lower than the input voltage or the battery is short circuited, CXLB73253 continues to charge the battery with a smaller current under the joint action of the off chip N-channel MOSFET and P-channel MOSFET, providing protection for the battery. Other functions include chip enable input, chip over temperature protection, current detection resistor short circuit protection, and status indication output terminal. CXLB73253 adopts an 8-pin SOP8 package.
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[ CXLB73253 ]"
