■ 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