R5422N111C Datasheet, PDF (1/9 Pages) RICOH electronics devices division – Li-lon BATTERY PROTECTOR

PRELIMINARY
’99.12.9
Li-Ion BATTERY PROTECTOR
R5422NxxxC/xxxE series
n OUTLINE
The R5422NxxxC/E 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, charger's negative pin level after the delay time by setting an
external capacitor. 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 R5422NxxxC/E version.
The output of DOUT pin, the output of over-discharge detector/VD2, switches to low level after internally fixed delay time passed,
when discharging voltage crosses the detector threshold from a high value to a value lower than VDET2.
After R5422NxxxC/E Series detect the over-discharge voltage, connect a charger to the battery pack, and when the battery
supply voltage becomes higher than the over-discharge detector threshold, VD2 is released and the voltage of DOUT becomes
“H” level.
An excess load current can be sensed and cut off after internally fixed delay time passed through the built in excess current
detector, VD3, with DOUT being enabled to low level. Once after detecting excess current, the VD3 is released and DOUT level
switches to high by detaching a battery pack from a load system.
Further, short circuit protector makes DOUT level to low immediately with external short circuit current and removing external
short circuit leads DOUT level to high. After detecting over-discharge, supply current will be kept extremely low by halt some
internal circuits operation. Output type of COUT and DOUT is CMOS. 6-pin, SOT23-6 is available.
n FEATURES
l High Voltage Process Technology
Absolute Maximum Rating of Voltage level between VDD-V- 28v
l Low supply current....................................................Supply current
Typ. 6.0µA
Standby current (detecting over-discharge) Typ. 0.1µA
l High accuracy detector threshold ..............................Over-charge detector (Topt=25°C)
±25mV
(Topt=0 to 50°C)
±30 mV
Over-discharge detector
±2.5%
Excess current detector
±20mV
l Variety of detector threshold .....................................Over-charge detector threshold
4.0V - 4.5V step of 0.01V
Over-discharge detector threshold 2.0V - 3.0V step of 0.01V
l Built-in protection circuit ..........................................Excess current protection
0.05V - 0.4V step of 0.01V
l Output delay of over-charge ......................................Time delay at C=0.01µF tVDET1=75ms, tVREL1=20ms
l Output delay of over-discharge .................................Internally fixed TYP. 17ms
l Output delay of excess-current
Internally fixed TYP. 10ms
l 2 Over-current modes
Excess Current Mode / Short Mode
l Charging Available / non-available at 0V Cell
Acceptable of 0V Cell C version
Non-acceptable of 0V Cell E versi on
l Small package............................................................SOT-23-6 / 6-pin
n APPLICATIONS
l Li+ one-cell protector for battery pack
Rev. 0.01
-1-