锂电池保护芯片R5478规格书.pdf

R5478N_Edoc/2010/12/14 PRELIMINARY Li-ION/POLYMER 1CELL PROTECTOR R5478Nxxxx SERIES OUTLINE The R5478Nxxxxx Series are high voltage CMOS-based protection ICs for over-charge/discharge of re- chargeable one-cell Lithium-ion (Li+) / Lithium polymer excess load current, further include a short circuit protector for preventing large external short circuit current and Excess charge/discharge-current. Each of these ICs is composed of three voltage detectors, a reference unit, a delay circuit, a short circuit protector, an oscillator, a counter, and a logic circuit. When the over-charge voltage crosses the detector threshold from a low value to a high value, the output of COUT pin switches to low level after internal fixed delay time. The conditions to release over-charge detector are different by mask options. In terms of so called “Latch function” version, after detecting over-charge, the detector can be reset and the output of COUT becomes H when a kind of load is connected to VDD after a charger is disconnected from the battery pack, and the cell voltage becomes lower than over-charge detector threshold. If a charger is continue to be connected to the battery pack, even the cell voltage becomes lower than over-charge detector threshold, over-charge state is not released. On the other hand, in terms of so called, “ Released by voltage level” version, after detecting over-charge, when the cell voltage reaches the released voltage from over-charge, the output of COUT becomes “H” The output of DOUT pin, the output of Over-discharge detector and Excess discharge-current detector, switches to “L” level after internally fixed delay time, when dischar