■ OUTLINE
The R5421NxxxC/F Series are protection ICs for over-charge/discharge of rechargeable one-cell Lithium-ion (Li+) excess load current, further include a short circuit protector for preventing large external short circuit current.
Each of these ICs is composed of three voltage detectors, a reference unit, a delay circuit, a short circuit protector, and a logic circuit. When charging voltage crosses the detector threshold from a low value to a value higher than VDET1, the output of COUT pin, the output of over-charge detector/VD1, switches to low level, chargers negative pin level. After detecting over-charge the VD1 can be reset and the output of COUT becomes high when the VDD voltage is coming down to a level lower than “VREL1”, or when a kind of loading is connected to VDD after a charger is disconnected from the battery pack while the VDD level is in between “VDET1” and “VREL1” in the R5421NxxxC/F version.

■ FEATURES
● Low supply current....................................................Supply current Typ. 3.0µA
                                         Standby current (detecting over-discharge) Typ. 0.3µA
                                                                                                   (for R5421NxxxC)
                                                                                                               Typ. 1.0µA
                                                                                                    (for R5421NxxxF)
● High accuracy detector threshold ..............................Over-charge detector (Topt=25°C) ±25mV
                                                                                         (Topt=0 to 50°C) ±30 mV
                                                                                         Over-discharge detector ±2.5%
● Variety of detector threshold ..............Over-charge detector threshold 4.0V - 4.4V step of 0.005V
   Over-discharge detector threshold 2.0V - 3.0V step of 0.005V
● Built-in protection circuit ......................Excess current protection 0.05V - 0.4V step of 0.005V
                                                                 Accuracy ±15%
● Output delay of over-charge.................Time delay at C3=0.01µF and VDD=4.3V
                                                                 75ms for R5421N111C
● Output delay of over-discharge ..............................VDD=2.4V with built-in capacitor
                                                                                   10ms for R5421N111C/112C
● Small package............................................................SOT-23-6 / 6-pin

■ APPLICATIONS
● Li+ one-cell protector for battery pack
● High precision protectors for cell-phones and any other gadgets using on board Li+ one-cell battery