SC8261G LI+ BATTERY PROTECTION CIRCUIT DESCRIPTION SC8261G is a LI+ battery protection circuit. It is suitable for protecting LI+ battery against damage from over charge, over discharge, and over current. It contains high accurate voltage detection and delay circuits. FEATURES * Low supply current * Over-charge detect 4.280V, Over-charge release 4.110V. * Over-discharge detect 3.00V, Over-discharge release 3.00V. * Over-current detect 0.15V, Short Current detect 1.00V. * Overcharge/over-discharge/over-current detection delay * Charger detection * Reset resistance for over current protection * Wide supply voltage range * Small package ORDERING INFORMATION Device Package Seal SC8261G SOT-23-6 8261G APPLICATIONS * Protection IC for One-Cell LI+ Battery Pack BLOCK DIAGRAM HANGZHOU MICROELECTRONICS CO.,LTD Http:// www.silan.com.cn REV:1.3 2008.09.01 Page 1 of 10 SC8261G ABSOLUTE MAXIMUM RATING Characteristics Symbol Value Unit Supply Voltage VDD VSS-0.3 ~ VSS+12 V OC Output Pin Voltage VOC VDD-15 ~ VDD+0.3 V OD Output Pin Voltage VOD VSS-0.3 ~ VDD+0.3 V CSI Input Pin Voltage VCSI VDD-15 ~ VDD+0.3 V Operating Temperature Range TOPR -40 ~ + 85 °C Storage Temperature Range TSTG -40 ~ +125 °C ELECTRICAL CHARACTERISTICS (Tamb=25°C, unless otherwise specified) Characteristics Symbol Status Min. Typ. Max. Unit 8.0 V Operating Voltage Operating Voltage VDD 1.8 Current Consumption Supply Current IDD VDD=3.9V Power Down Current IPD VDD=2.0V 3.0 μA 6.0 0.3 0.6 μA Detection Voltage Over Charge Detection Voltage VOCU 4.255 4.280 4.305 V Over Charge Release Voltage VOCR 4.075 4.110 4.145 V Over Discharge Detection Voltage VODL 2.90 3.00 3.10 V Over Discharge Release Voltage VODR 2.90 3.00 3.10 V Over Current 1 Detection Voltage VOI1 0.13 0.15 0.17 V Over Current 2(Short Current)Detection VOI2 VDD=3.6V 0.80 1.00 1.20 V Over Current Reset Resistor Rshort VDD=3.6V 400 500 600 kΩ Charger Detection Voltage VCH -0.8 -0.5 -0.2 V Voltage Delay Time Over Charge Detection Delay Time TOC VDD=3.6V~4.4V 150 340 500 ms Over Discharge Detection Delay Time TOD VDD=3.6V~2.0V 80 200 300 ms Over Current 1 Detection Delay Time TOI1 VDD=3.6V 5 13 20 ms TOI2 VDD=3.6V 5 50 μs Over Current 2(Short Current)Detection Delay Time Other OC Pin Output “H” Voltage Voh1 OC Pin Output “L” Voltage Vol1 OD Pin Output “H” Voltage Voh2 OD Pin Output “L” Voltage Vol2 HANGZHOU MICROELECTRONICS CO.,LTD Http:// www.silan.com.cn VDD-0.1 VDD-0.02 0.01 V 0.1 VDD-0.1 VDD-0.02 0.01 V V 0.1 REV:1.3 V 2008.09.01 Page 2 of 10 SC8261G PIN CONFIGURATION PIN DESCRIPTIONS PIN No. Symbol I/O Description 1 OD O FET gate connection pin for discharge control. 2 CSI I/O Input pin for current sense, charger detect. 3 OC O FET gate connection pin for charge control. 4 TD I Test pin for reduce delay time. 5 VDD I Positive power input pin. 6 VSS I Negative power input pin. FUNCTION DESCRIPTIONS Normal Status If VODL<VDD<VOCU and VCH<VCSI<VOI1, M1 and M2 are both turned on (refer to Typical Application Circuits). The charging and discharging processes can be operated normally. Overcharge Detection When enter charging from normal status, the battery voltage can be detected from VDD. When the battery is in overcharge status, VDD is larger than VOCU over a delay time of TOC, M2 is to be turned off. Release of Overcharge Status There are two ways to return to normal status from overcharge status. • If the battery is self discharging and VDD<VOCR occurs, M2 is to be turned on and back to normal status. • Remove the charger and connected to a load. If VOCR<VDD<VOCU and VCSI>VOI1 occurs, M2 is to be turned on and back to normal status. Over discharge Detection When enter discharging from normal status, the battery voltage can be detected from VDD. When the battery is in over discharge status, VDD is smaller than VODL over a delay time of TOD; M1 is to be turned off. In the meanwhile, CSI is pulled to VDD by way of internal resistor RCSID. If VCSI>VOI2, the protection IC enters into Power-down mode. (Its current consumption is lower than 0.3μA). HANGZHOU MICROELECTRONICS CO.,LTD Http:// www.silan.com.cn REV:1.3 2008.09.01 Page 3 of 10 SC8261G Release of Power-down mode A charger is connected while the battery remains in Power-down mode. If VCH<VCSI<VOI2 and VDD<VODR occur, M1 is still off but it releases Power-down mode. If VDD>VODR occurs, M1 is to be turned on and back to normal status. Charger Detection If a charger is connected to the battery remained in Power-down mode, the voltages will become VCSI<VCH and VDD>VODL. M1 is to be turned on and back to normal status. Abnormal Charging Status If a charger is connected to the battery in normal status, VCSI<VCH occurs over a delay time longer than TOC, M2 is to be turned off. Over Current/Short Current Detection When the discharging current is too large during discharging under normal status and the voltage detected from CSI is larger than VOIX (VIO1 or VIO2) for over a certain delay time TOIX (TIO1 or TIO2), it means the over current/short current status occurred. M1 is turned off. CSI is pulled to VSS by way of an internal resistor RCSIS. Release of Over Current/Short Current Status While the protection IC remains in Over Current/Short Current status and load is removed or the impedance between VBAT+ and VBAT- is larger than 500KΩ and VCSI<VOI1, M1 is to be turned on and back to normal status. Note: when a battery is connected to a protection IC for the first time, the IC may not enter the normal status (not dischargeable status). If this occurs, set the CSI pin voltage equal to the VSS voltage (short the CSI and VSS pins or connect a charger) to enter the normal status. HANGZHOU MICROELECTRONICS CO.,LTD Http:// www.silan.com.cn REV:1.3 2008.09.01 Page 4 of 10 SC8261G TIMING DIAGRAM Overcharge Status →Self Discharging →Normal Status Overcharge Status→Load Discharging→Normal Status HANGZHOU MICROELECTRONICS CO.,LTD Http:// www.silan.com.cn REV:1.3 2008.09.01 Page 5 of 10 SC8261G Overcharge Status→Charging By Charger→Normal Status CSI pin OD pin OC pin Battery voltage Overcharge Status→Abnormal Status→Normal Status HANGZHOU MICROELECTRONICS CO.,LTD Http:// www.silan.com.cn REV:1.3 2008.09.01 Page 6 of 10 SC8261G Over Current Status→Normal Status STATE DIAGRAM OF OPERATION HANGZHOU MICROELECTRONICS CO.,LTD Http:// www.silan.com.cn REV:1.3 2008.09.01 Page 7 of 10 SC8261G TYPICAL APPLICATION CIRCUITS Note: The circuit and parameters are reference only, please set the parameters of the real application circuit based on the real test. PACKAGE OUTLINE SOT-23-6 HANGZHOU MICROELECTRONICS CO.,LTD Http:// www.silan.com.cn UNIT: mm REV:1.3 2008.09.01 Page 8 of 10 SC8261G HANDLING MOS DEVICES: Electrostatic charges can exist in many things. All of our MOS devices are internally protected against electrostatic discharge but they can be damaged if the following precautions are not taken: • Persons at a work bench should be earthed via a wrist strap. • Equipment cases should be earthed. • All tools used during assembly, including soldering tools and solder baths, must be earthed. • MOS devices should be packed for dispatch in antistatic/conductive containers. Note：Silan reserves the right to make changes without notice in this specification for the improvement of the design and performance. Silan will supply the best possible product for customers. HANGZHOU MICROELECTRONICS CO.,LTD Http:// www.silan.com.cn REV:1.3 2008.09.01 Page 9 of 10