AIC1803 Three-Cell Lithium-Ion Battery Protection IC n FEATURES n DESCRIPTION l Ultra-Low Quiescent Current at 13A (V CELL=3.5V). l Ultra-Low Power-Down Current at 1.3A (V CELL=2.3V) l Wide Supply Voltage Range: 2V to 18V. Precision Overcharge Protection Voltage: l The AIC1803 is designed to protect the lithiumion battery from damage or degrading the lifetime due to overcharging, overdischarging and overcurrent for three-cell lithium-ion battery powered systems such as notebook PCs. It can also provide the cell-balancing "bleeding" function to automatically discharge the overcharged cell until the overcharge condition is released. 4.35V 30mV for the AIC1803A 4.30V 30mV for the AIC1803B 4.25V 30mV for the AIC1803C 4.20V 30mV for the AIC1803D l l l n l n Externally Set Overcharge, Overdischarge and Overcurrent Delay Time. Built-in Cell-balancing Bleeding Network under Overcharge Condition. Three Detection Levels for Overcurrent Protection. Safe and full utilization charging is ensured by the accurate 30mV overcharge detection. Four different specification values for overcharge protection voltage are provided for various protection requirements. The very low standby current drains little current from the cell while in storage. APPLICATIONS Protection IC for Three-Cell Lithium-Ion Battery Pack. TYPICAL APPLICATION CIRCUIT R8 1K 1 2 OC VCC CS VC1 16 R4 C4 0.1 F 1K M1 FUSE M2 15 BATT+ C1 R1 2K 0.1 F 3 4 OD UD1 NC VC2 R5 1M BAT1 14 Q1 13 R2 2K C2 0.1 F 5 6 CTD 82nF CTI 2.2nF 7 CTC 82nF 8 TD TI UD2 VC3 TC UD3 NC GND BAT2 12 R6 1M R7 1M 11 R3 33K 10 C3 0.1F 9 BAT3 BATT- AIC1803 Protection Circuit for Three-Cell Lithium-Ion Battery Pack DS-1803-01 July 14, 00 www.analog.com.tw 1 AIC1803 n ORDERING INFORMATION AIC1803 XXX ORDER NUMBER PIN CONFIGURATION TOP VIEW PACKAGE TYPE S: SMALL OUTLINE AIC1803ACS AIC1803BCS AIC1803CCS AIC1803DCS (PLASTIC SO) TEMPERATURE RANGE C=0C~70 C OVERCHARGE PROTECTION VOLTAGE A: 4.35V B: 4.30V C: 4.25V D: 4.20V OC 1 16 VCC CS 2 15 VC1 OD 3 14 UD1 NC 4 13 VC2 TD 5 12 UD2 TI 6 TC 7 11 VC3 10 UD3 NC 8 9 GND n ABSOLUTE MAXIMUM RATINGS Supply Voltage ................................................... ... ... ... ... ... ....................................... 18V DC Voltage Applied on other Pins ............ ... ... ... ... ... ... ..... ....................................... 18V Operating Temperature Range............................... ... ... ... ... ... ......................... -20C~70C Storage Temperature Range ................................ ... ..... ... ... ..................... - 65C ~125C n TEST CIRCUIT ROC 1M I OC S1 1 V OC R8 V CS 2 OC VCC CS VC1 16 15 I CC IC 1 1K 3 VOD 4 OD UD1 NC VC2 14 13 I UD1 R4 1K C4 0.1 F C1 0.1F R1 2K V C1 I C2 VC2 R2 2K 5 6 CTD 82nF CTI 7 2.2nF CTC 8 TD UD2 TI VC3 TC UD3 GND NC 12 11 IUD2 C2 0.1F IC 3 R3 33K 10 I UD3 VC3 C3 0.1F 9 82nF AIC1803 2 AIC1803 n ELECTRICAL CHARACTERISTICS (Ta=25C, unless otherwise specified.) PARAMETER TEST CONDITIONS SYMBOL MIN. TYP. MAX. UNIT VCC Pin Input Current in Normal VCELL=3.5V Mode ICC 13 20 A VC1 Pin Input Current in Normal VCELL=3.5V Mode IC1 0.4 1.0 A VC2 Pin Input Current in Normal VCELL=3.5V Mode IC2 0.4 1.0 A VC3 Pin Input Current in Normal VCELL=3.5V Mode IC3 0.2 0.5 A Vcc Pin Input Current in PowerDown Mode VCELL=2.3V ICC(PD) 1.3 2 A VC1,VC2,VC3 Input Current in Power-Down Mode VCELL=2.3V IC(PD) 0.01 0.15 A 4.32 4.35 4.38 4.27 4.30 4.33 AIC1803C 4.22 4.25 4.28 AIC1803D 4.17 4.20 4.23 AIC1803A AIC1803B VOCP V Overcharge Protection Voltage Overcharge Hysteresis Voltage VHYS 150 200 250 mV Overdischarge Protection Voltage VODP 2.27 2.40 2.53 V Overdischarge Release Voltage VODR 2.85 3.00 3.15 V VOIP 135 150 165 mV TOC 10 21 32 mS TOD 10 21 32 mS TOI1 7 15 23 mS Overcurrent Protection Voltage VCELL=3.5V VCELL1 = VOCP30mVVOCP+30mV Overcharge Delay Time VCELL2= VCELL3=3.5 V , CT C=1nF VCELL1= 2.5V 2.3V Overdischarge Delay Time Overcurrent Delay Time (1) VCELL2= VCELL3=3.5V , CTD=1nF VCELL= 3.5V,0.15V<VCC VCS <0.3V,CTI=2.2nF 3 AIC1803 n ELECTRICAL CHARACTERISTICS (Ta=25C, unless otherwise specified.) PARAMETER TEST CONDITIONS Overcurrent Delay Time (2) Overcurrent Delay Time (3) SYMBOL MIN. TOI2 2 4 6 mS TOI3 150 300 450 S IOC 2.0 2.8 3.6 mA VC C-0.03V V 0.15 V VCELL=3.5V, 0.3V<VCC-V CS<1.0V VCELL=3.5V, VCC- VCS>1.0V TYP. MAX. UNIT VCELL1=4.4V, VCELL2= VCELL3=3.5V, OC Pin Sink Current OC Pin Short to VCC OD Pin Output "H" Voltage VDH OD Pin Output "L" Voltage VDL Charge Detection Threshold Voltage VCELL=2.3V VC C-0.15V 0.01 VCH VC C+0.4 VCC+0.55 V UD1 Pin Cell-Balancing Bleeding VCELL1=4.4V, Current VCELL2= VCELL3=3.5V IUD1 5.9 8.4 10.9 mA UD2 Pin Cell-Balancing Bleeding VCELL2=4.4V, Current VCELL1= VCELL3=3.5V IUD2 6.1 8.7 11.3 mA UD3 Pin Cell-Balancing Bleeding VCELL3=4.4V, Current VCELL1= VCELL2=3.5V IUD3 6.4 9.2 12.0 mA Note: VCELL means the battery cell voltage. Therefore, VCELL1 = VC1 - V C2 VCELL2 = VC2 - V C3 VCELL3 = VC3 n TYPICAL PERFORMANCE CHARACTERISTICS Vcc Pin Power-Down Current vs. Supply Voltage Vcc Pin Input Current vs. Supply Voltage Vcc Pin Power-Down Current (A) Vcc Pin Input Current (A) 15 Ta=25C 14 13 12 11 7.8 8.4 9.0 9.6 10.2 Supply Voltage (V) 10.8 11.4 12.0 1.3 Ta=25C 1.2 1.1 1.0 0.9 0.8 4.5 4.8 5.1 5.4 5.7 6.0 6.3 6.6 6.9 Supply Voltage (V) 4 AIC1803 n TYPICAL PERFORMANCE CHARACTERISTICS (CONTIONED) Vcc Pin Power-Down Current vs. Temperature Vcc Pin Input Current vs. Temperature 2.0 Vcc Pin Power-Down Current (A) Vcc Pin Input Current (A) 16 VCELL =3.5V 1.8 15 1.6 14 1.4 13 1.2 12 1.0 11 10 VCELL=2.3V -20 -10 0 10 20 30 40 Temperature (C) 50 60 0.8 70 -20 0 10 20 30 40 50 60 70 Temperature (C) Overdischarge Protection Voltage vs. Temperature Overcharge Protection Voltage vs. Temperature 2.42 Overdischarge Protection Voltage (V) 4.30 Overcharge Protection Voltage (V) -10 AIC1803C 2.41 4.28 2.40 4.26 2.39 4.24 2.38 4.22 4.20 2.37 -20 0 20 40 60 70 2.36 Overcurrent Protection Voltage vs. Temperature Overcurrent Protection Voltage (V) 152.0 151.5 V CELL=3.5V 151.0 150.5 150.0 149.5 149.0 148.5 148.0 -20 -10 0 10 20 30 Temperature(C) 40 50 60 70 Overcharge/Overdischarge Delay Time (mS) Temperature (C) -20 -10 0 10 20 30 40 Temperature (C) 50 60 70 Overcharge/Overdischarge Delay Time vs. Temperature 26 CTC /CTD=1nF 24 22 20 18 16 14 -20 -10 0 10 20 30 40 50 60 70 Temperature( C) 5 AIC1803 n TYPICAL PERFORMANCE CHARACTERISTICS (CONTIONED) Overcurrent Delay Time 1 vs. Temperature Overcharge Release Voltage vs. Temperature 4.08 Overcharge Release Voltage (V) Overcurrent Delay Time 1 (mS) 22 20 VCELL =3.5V 18 16 14 12 10 -20 -10 0 10 20 30 40 50 60 70 Temperature (C) 4.07 4.06 4.05 4.04 4.03 4.02 -20 -10 0 10 20 30 40 50 60 70 Temperature ( C) Overdischarge Release Voltage vs. Temperature Overdischarge Release Voltage (V) 3.01 3.00 2.99 2.98 2.97 -20 -10 0 10 20 30 40 50 60 70 o Temperature (C) 6 AIC1803 n BLOCK DIAGRAM CS 2 VC1 15 Battery Voltage Sense Circuit VC2 13 VC3 UD1 16 VCC VCC-0.15V Overcurrent Delay Circuit 11 VCC-0.3V 14 3 350 VCC-1V UD2 12 Overdischarge Delay Circuit 400 UD3 Wake-up Control VCC+0.4V 10 Power-Down Control 1 OD OC Overcharge Delay Circuit 450 1.2V GND 9 7 5 6 TC TD TI 7 AIC1803 n PIN DESCRIPTIONS PIN 1: OC- PIN 2: CS- NMOS open drain output for control of the charge control MOSFET M2. When overcharge occurs, this pin sinks current to switch the external PNP Q1 on, and charging is inhibited by turning off the charge control MOSFET M2. Input pin for current sensing. Using the drain-source voltage of the discharge control MOSFET M1 (voltage between VCC and CS), it senses discharge current during normal mode and detects whether charging current is present during power-down mode. connected to the negative terminal of the battery cell BAT3. PIN10: UD3 - This pin is to be connected to the positive terminal of the battery cell BAT3 for cell-balancing bleeding function under overcharge condition. PIN11: VC3- Input pin for battery BAT3 voltage sensing. This pin is to be connected to the positive terminal of the battery cell BAT3. PIN12: UD2 - This pin is to be connected to the positive terminal of the battery cell BAT2 for cell-balancing bleeding function under overcharge condition. PIN13: VC2- PIN 3: OD - Output pin for control of discharge control MOSFET M1. PIN 4: NC - No connection PIN 5: TD - Overdischarge delay time setting pin. PIN 6: TI - Overcurrent delay pin. PIN 7: TC - Overcharge delay time setting pin. Input pin for battery BAT2 voltage sensing. This pin is to be When overdischarge occurs, this pin goes high connected to the positive terminal of the battery cell BAT2. PIN14: UD1- This pin is to be connected to the positive ter PIN15: VC1- Input pin for battery BAT1 voltage sensing. This pin is to be connected to the positive terminal of the battery cell BAT1. PIN16: VCC - Power supply pin. This pin is to be connected to the positive terminal of the battery cell BAT1. time setting PIN 8: NC - No connection. PIN 9: GND - Ground pin. This pin is to be n APPLICATION INFORMATIONS l THE OPERATION Initialization beyond the overcharge delay time (TOC ) period, charging is inhibited by the turning-off of the charge control MOSFET M2. The overcharge On initial power-up , such as connecting the delay time is set by the external capacitor CTC. battery pack for the first time to the AIC1803 , the Inhibition of charging is immediately released AIC1803 enters the power-down mode . A charger when the voltage of the overcharged cell becomes must be applied to the AIC1803 circuit to enable lower than the pack. VOCP-V HYS) through discharging. Overcharge Protection Overdischarge Protection When the voltage of either of the battery cells When the voltage of either of the battery cells falls exceeds the overcharge protection voltage (V OCP) below the overdischarge protection voltage (V ODP) overcharge release voltage (V OCR or 8 AIC1803 beyond the overdischarge delay time (TOD) period, (V OCR or VOCP-vHYS ). This function is accomplished discharging is inhibited by the turning-off of the by connecting UD1, UD2, UD3 pins to the positive discharge terminals of battery cells BAT1, BAT2, BAT3 control MOSFET M1. The overdischarge delay time is set by the external respectively. The bleeding capacitor CTD. Inhibition of discharging current can be is decreased by inserting resistors along UD1 pin to immediately released when the voltage of the BAT1 positive terminal path and UD3 pin to BAT3 overdischarge cell becomes higher than the positive terminal path. overdischarge release voltage (V ODR) through charging. Power-Down after Overdischarge When overdischarge occurs, the AIC1803 will go Overcurrent Protection continuously into power-down mode, turning off all the timing monitors the discharge current by sensing the generation and detection circuitry to reduce the voltage of CS pin. If the voltage VCC-V CS exceeds quiescent current to about 1.3A (V CC =6.9V). In the overcurrent protection voltage (V OIP) beyond the unusual case where one battery cell is the overcurrent delay time (TOI) period, the overdischarged overcurrent and overcharge condition, the AIC1803 will turn off all discharging is inhibited by the turning-off of the the detection circuitry except the overcharge discharge control MOSFET M1. Discharging must detection circuit for the cell under overcharge be inhibited for at least 256mS after overcurrent condition. In normal mode, the protection AIC1803 circuit operates while another one under takes place to avoid damage to external control MOSFETs due to rapidly switching transient Charge Detection after Overdischarge between The When overdischarge occurs, the discharge control overcurrent condition returns to normal mode MOSFET M1 turns off and discharging is inhibited. when the load is released and the impedance However, charging is still permitted through the between the BATT+ and BATT- terminals is parasitic diode of M1. Once the charger is 20M or higher. connected to the battery pack, the AIC1803 The BATT+ AIC1803 and is BATT- provided terminals. with the three overcurrent detection levels (0.15V, 0.3V and 1.0V) and the three overcurrent delay time (TOI1, TOI2 and TOI3) corresponding to each overcurrent detection level. TOI1 is set by the external capacitor immediately turns on all the timing generation and detection circuitry and goes into normal mode. Charging is determined to be in progress if the CS pin voltage is higher than VCC + 0.4V (charge detection threshold voltage VCH). CTI. TOI2 and TOI3 default to 4mS and 300s respectively, and can not be adjusted due to protection of external MOSFETs Cell-Balancing Overcharge Bleeding after * DESIGN GUIDE Setting the Overcharge Overdischarge Delay Time and When either of the battery cells is overcharged, The overcharge delay time is set by the external the AIC1803 provides the cell-balancing bleeding capacitor CTC and the overdischarge delay time is function to discharge the overcharged cell at set by the external capacitor CTD. The relationship about 9mA until the voltage of the overcharged between capacitance of the external capacitors cell decreases to overcharge release voltage and delay time is tabulated as below. 9 AIC1803 CTC CT D(F) TOC T OD(S) CTC CT D(F) TOC T OD(S) 1n 21m 47n 617m 5n 52m 10n 132m 68n 748m 22n 253m 33n 347m be aware that turn-on resistance of the MOSFET changes with temperature variation due to heat dissipation. It changes with the voltage between 82n 100n 1004m 1630m gate and source as well. (Turn-on resistance of a MOSFET increases as the voltage between gate The delay time can also be approximately and calculated by the following equations (if CTC , CTD resistance of the external MOSFET changes, the 82nF) : source overcurrent decreases). current the turn-on will change Suppressing the Ripple Disturbance from Charger and Setting the Overcurrent Delay Time 1 The overcurrent delay time 1 (TOI1) at 0.15V < To suppress the ripple and disturbance from VCC-VCS < 0.3V is set by the external capacitor CTI, charger, connecting R1 to R4 and C1 to C4 is while the overcurrent delay time 2 and 3 (TOI2 and recommended. TOC (mS) = 11.8 x CTC(nF) threshold Once accordingly. TOD (mS) = 11.8 x CTD(nF) TOI3) is fixed by IC internal circuit.The relationship between capacitance of the external capacitor and delay time is tabulated as below. CTI(F) 1n 2.2n 3.3n 5n TOI(mS) 4.8 15.0 18.8 23.6 6.8n 31.0 10n 61.8 Controlling MOSFET the Charge Control R5, R6, R7 and NPN transistor Q1 are used to switch the charge control MOSFET M2. If overcharge does not occur, no current flows into Selection MOSFETs of External Control Because the overcurrent protection voltage is OC pin and Q1 is turned off, then M2 is turned on. When overcharge occurs, current flows into OC pin and Q1 is turned on, which turns off M2 in turn. preset, the threshold current for overcurrent detection is determined by the turn-on resistance of the discharge control MOSFET M1. The turn-on Protection at CS Pin resistance of the external control MOSFETs can R8 is used for protection of IC when charger is be determined by the equation: RON=VOIP/IT (IT is connected in reverse. The charge detection the overcurrent threshold current). For example, if function after overdischarge is possibly disabled the overcurrent threshold current IT is designed to by larger value of R8. Resistance of 1K is be 5A, the turn-on resistance of the external recommended. control MOSFETs must be 30m. Users should 10 AIC1803 n TIMING DIAGRAM l Overcharge and Overdischarge Protection (VCS=VCC ) <TOC TOC V BAT1 V OCP V OCP - VHYS VCELL V BAT2 V BAT3 V ODR V ODP TOD <T OD VOC VOD Hi-Z Hi-Z 0V V CC 0V l Overcurrent Protection (VCELL=3.5V) <256ms >256ms VCC VCC- 0.15V VCC - 0.3V VCS VCC - 1V 0V TOI1 <TOI2 VOD <T TOI3 OI1 VCC 0V 256ms <256ms VOC Hi-Z 11 AIC1803 n PHYSICAL DIMENSIONS l 16 LEAD PLASTIC SO (150 mil) (unit: mm) D H E SYMBOL MIN MAX A 1.35 1.75 A1 0.10 0.25 B 0.33 0.51 C 0.19 0.25 D 9.80 10.00 E 3.80 4.00 e e H 5.80 6.20 L 0.40 1.27 A1 A 1.27 (TYP) B C L 12