The R5472 is high voltage tolerance CMOS-based protection IC for over-charge/discharge and over-current of rechargeable one-cell Lithium-ion (Li+)/Lithium polymer battery. The R5472 can detect over-charge/discharge of Li+ one-cell and excess load current, further include a short circuit protector for preventing large external short circuit current and the excess charge-current. The R5472 consists of four voltage detectors, a reference unit, a delay circuit, a short circuit detector, an oscillator, a counter, and a logic circuit.
When the R5472 detects over-charge or over-charge current, the output of COUT pin switches to "L" level, that is, the charger's negative pin level after the internal fixed delay time. When the R5472 detects over-discharge or excess discharge current, the output of DOUT pin switches to “L” level after the internal fixed delay time.
After detecting over-charge or excess charge current, the R5472 can be reset and the output of COUT becomes "H" when a charger is disconnected from the battery pack, and the cell voltage becomes lower than over-charge detector threshold.
However, depending on the characteristics of external components such as MOSFETs, release conditions may be not enough just removing a charger from the battery pack. In that case, a kind of load must be set to release the over-charge detect.
If a charger is continuously connected to the battery pack, even if the cell voltage becomes lower than over-charge detector threshold, over-charge state is not released.
After detecting over-discharge voltage, connect a charger to the battery pack, and when the battery supply voltage becomes higher than over-discharge detector threshold, the R5472 is released and the voltage of DOUT pin becomes "H". If the battery is discharged lower than maximum voltage for inhibition of charger, recharge current is not acceptable. Once after detecting excess discharge-current or short circuit, the R5472 is released and DOUT level becomes "H" with detaching a battery pack from a load system. After detecting over-discharge, supply current is kept extremely low by halting internal circuits' operation.
When the output of COUT is "H", by setting the V- pin at equal or lower than the delay shortening mode voltage (Typ. -2.0V), the output delay can be shortened. Especially, the delay time of over charge detector can be reduced into approximately 1/110. Thus, testing time of protector circuit board can be reduced. Output type of COUT and DOUT is CMOS.
|Manufactured with High Voltage Tolerant Process|
|Absolute Maximum Rating||30 V|
|Low supply current|
|Supply current (At normal mode)||TYP. 4.0 µA|
|Standby current||MAX. 0.1 µA|
|High accuracy detector threshold|
|Over-charge detector||±20 mV|
|Over-discharge detector||±35 mV|
|Excess discharge-current detector||±10 mV|
|Excess charge-current detector||±10 mV|
|Variety of detector threshold|
|Over-charge detector threshold||4.1 V ~ 4.405 V step of 0.005 V|
|Over-discharge detector threshold||2.1 V ~ 3.0 V step of 0.005 V|
|Excess discharge-current threshold||0.050 V ~ 0.12 V step of 0.005 V|
|Excess charge-current threshold||-0.050 V ~ -0.12 V step of 0.005 V|
|Internal fixed Output delay time|
|Over-charge detector Output Delay||1.0 s|
|Over-discharge detector Output Delay||20 ms|
|Excess discharge-current detector Output Delay||12 ms|
|Excess charge-current detector Output Delay||16 ms|
|Short Circuit detector Output Delay||250 µs|
|Output Delay Time Shortening Function||At COUT is "H", if V- level is set at -2.0V, the Output Delay time of detect the over-charge and over-discharge can be reduced. (Delay Time for over-charge becomes about 1/100 of normal state.)|
|Conditions for release over-charge detector||Latch type|
|Conditions for release over-discharge detector||Latch type|
|0V-battery charge option||unacceptable|
|Ultra Small package||R5472L : DFN1414-6, R5472K : DFN(PLP)1414-6|