SC8201 ONE-CELL LI+ BATTERY PROTECTION CIRCUIT DESCRIPTION SC8201 is a LiFePO4 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 consumption current VDD=3.4V, IDD=(Typ. 3μA) VDD=1.8V, IDD=(Typ. 0.3μA) * Wide supply voltage range: (1.8V~8V) * Over-charge detection voltage 3.65V, Over-charge release voltage 3.45V. * Over-discharge detection voltage 2.00V, Over-discharge release voltage 2.50V. * Over current detect voltage 0.15V, Short Current detection voltage 1.00V. * Overcharge/over-discharge/over-current detection delay times are generated by an internal circuit * Charger detection * Over current protection ORDERING INFORMATION Device Package Seal Name SC8201 SOT-23-6 8201 APPLICATIONS * Protection IC for One-Cell LiFePO4 Battery Pack * Small package BLOCK DIAGRAM HANGZHOU MICROELECTRONICS CO.,LTD Http://www.silan.com.cn REV:1.3 2008.06.25 Page 1 of 10 SC8201 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 Conditions Min. Typ. Max. Unit 8.0 V Operating Voltage Operating Voltage VDD 1.8 Current Consumption Supply Current IDD VDD=3.4V 3.0 6.0 μA Power Down Current IPD VDD=1.8V 0.3 0.6 μA Detection Voltage Over Charge Detection Voltage VOCU 3.620 3.650 3.680 V Over Charge Release Voltage VOCR 3.415 3.450 3.485 V Over Discharge Detection Voltage VODL 1.90 2.00 2.10 V Over Discharge Release Voltage VODR 2.40 2.50 2.60 V Over Current 1 Detection Voltage VOI1 0.13 0.15 0.17 V Over Current (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 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 REV:1.3 V V 0.1 V 2008.06.25 Page 2 of 10 SC8201 PIN CONFIGURATION PIN DESCRIPTIONS PIN No. Symbol I/O 1 OD O FET gate connection pin for discharge control. 2 CSI I/O Detecting pin for current sense, charger detect. 3 OC O FET gate connection pin for charge control. 4 TD I Test pin for delay time. 5 VDD I Positive power input pin. 6 VSS I Negative power input pin. Description FUNCTION DESCRIPTIONS Normal state If VODL<VDD<VOCU and VCH<VCSI<VOI1, M1 and M2 (refer to the typical application circuit, they are used to control the charge/discharge state) are both turned on. The charging and discharging processes can be operated normally at this time. Overcharge Detection When enter overcharge state from normal state, the battery voltage can be detected from VDD. When the battery voltage VDD is larger than VOCU over a delay time of TOC, then enter the overcharge state from normal state and M2 is to be turned off. Release of Overcharge State There are two ways to return to normal state from overcharge state. • If the battery is self discharging and VDD<VOCR occurs, M2 is to be turned on and back to normal state. • 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 state. HANGZHOU MICROELECTRONICS CO.,LTD Http://www.silan.com.cn REV:1.3 2008.06.25 Page 3 of 10 SC8201 Overdischarge Detection When enter overdischarge state from normal state, the battery voltage can be detected from VDD. When the battery voltage 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). 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 state. Charge Detection If a charger is connected to the battery remained in Power-down mode, if VCSI<VCH and VDD>VODL, M1 is to be turned on and back to normal state. Abnormal Charging State If a charger is connected to the battery in normal state, 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 under normal state and the voltage detected from CSI is larger than VOI1 (VIO2) for over a certain delay time TOI1 (TIO2), it means the over current/short current state occurred. M1 is turned off. CSI is pulled to VSS by way of an internal resistor RCSIS. Release of Over Current/Short Current State While the protection IC remains in Over Current/Short Current state 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 state. Note: when a battery is connected to a protection IC for the first time, the IC may not enter the normal state (not dischargeable state). 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 state. HANGZHOU MICROELECTRONICS CO.,LTD Http://www.silan.com.cn REV:1.3 2008.06.25 Page 4 of 10 SC8201 TIMING DIAGRAM Overcharge State →Self Discharging →Normal State CSI pin OD pin OC pin Battery voltage Overcharge state→load discharging→normal state HANGZHOU MICROELECTRONICS CO.,LTD Http://www.silan.com.cn REV:1.3 2008.06.25 Page 5 of 10 SC8201 Overcharge State→Charging By Charger→Normal State Overcharge State→Abnormal State→Normal State HANGZHOU MICROELECTRONICS CO.,LTD Http://www.silan.com.cn REV:1.3 2008.06.25 Page 6 of 10 SC8201 Over Current State→Normal State Charger connection Load connection CSI pin OD pin OC pin Battery voltage VOCU VOCR VODR VODL VDD CSI VDD VSS VDD VOI2 VSS VCH TOI1 TOI2 STATE DIAGRAM OF OPERATION Abnormal charge Current condition (OC=0) (F) Over charge condition, (OC=0) (S) VCSI<VCH(-0.6V) & t>TOC(100ms) (H) VCSI>VOI1(0.15V) (E) & VDD>VOCU(4.35V) VDD<VOCU(4.35V) & t>TOC(100ms) (T) VCSI>VCH(-0.6V) OD=0 VCSI is shorted to VDD (pullup to VDD) via resistor RCSID (300k) (J) Overdischarge condition, (OD=0) (M) VCH<VCSI<VOI2 (G) VDD<VOCR(4.15V) (K) VCSI>VOI2 (I) VDD<VODL(2.4V) & t>TOD(10ms) (N) VDD>VODR(3.0v) (R) VCSI<VCH(-0.6v) (L) Power down condition OD=0 IDD≤IPD(0.3 A) VCSI is shorted to VDD (pull-up to VDD) via resistor RCSID (300k) (Q) VDD>VODL (A) Normal condition (OD=OC=1)@ VODL<VDD<VOCU & VCH<VCSI<VOI1 (B) VCSI>VOI1(0.15V) & t>tOI1(10ms) (C) VCSI>VOI2 & t>TOI2(5 s) (D) Load resistor >500kΩ Over current Ⅰ,Ⅱ Or short, (OD=0) (P) Charger detect @ Overcharge OD=0 SC8201 operation status diagram Release overdischarge Trickle charging by automatic charging HANGZHOU MICROELECTRONICS CO.,LTD Http://www.silan.com.cn REV:1.3 2008.06.25 Page 7 of 10 SC8201 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 2008.06.25 Page 8 of 10 SC8201 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 2008.06.25 Page 9 of 10