AIC1804 Three- Or Four-Cell Lithium-Ion Battery Protection IC n FEATURES n DESCRIPTION l Cell Number Selection Function to Select 3 or 4 cells Protection. l Ultra-Low Quiescent Current at 17µA (4-Cell, VCELL=3.5V). l Ultra-Low Power-Down Current at 2.2µA (4-Cell, VCELL=2.3V) Wide Supply Voltage Range: 2V to 18V. Precision Overcharge Protection Voltage: l l The AIC1804 is designed to protect the lithiumion battery from damage or degrading the lifetime due to overcharging, overdischarging and overcurrent for three- or four-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 AIC1804A 4.30V± 30mV for the AIC1804B 4.25V± 30mV for the AIC1804C l l l n l n 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. 4.20V± 30mV for the AIC1804D Externally Set Overcharge, Overdischarge and Overcurrent Delay Time. Built-in Cell-balancing Bleeding Network under Overcharge Condition. Three Detection Levels for Overcurrent Protection. APPLICATIONS Protection IC for Three- or Four-Cell Lithium-Ion Battery Packs. TYPICAL APPLICATION CIRCUIT R8 1K NSL VCC R1 16 UD1 15 OC 3 CS VC1 C2 0.1µ F 4 OD 5 TD C TC 82nF 8 R3 C4 GND UD4 R6 1M BAT3 R7 1M R4 VC3 9 BATT+ R5 1M 2K UD3 11 10 TI 7 TC FUSE BAT2 VC2 6 CT I 2.2nF 2K UD2 13 12 C3 0.1µ F CT D 82nF SI4435 M2 BAT1 R2 14 M1 200 C1 0.1µ F 2 SI4435 2N3906 Q1 1 33K 0.1µ F AIC1804 BAT4 BATT- Protection Circuit for Four-Cell Lithium-Ion Battery Pack DS-1804-01 July 13, 00 www.analog.com.tw 1 AIC1804 n ORDERING INFORMATION AIC1804 XXX ORDER NUMBER PIN CONFIGURATION TOP VIEW PACKAGE TYPE S: SMALL OUTLINE AIC1804ACS AIC1804BCS AIC1804CCS AIC1804DCS (PLASTIC SO) TEMPERATURE RANGE C=0 °C~70° C OVERCHARGE PROTECTION VOLTAGE A: 4.35V B: 4.30V C: 4.25V D: 4.20V NSL 1 16 VCC OC 2 15 UD1 CS 3 14 VC1 OD 4 13 UD2 TD 5 12 VC2 TI 6 TC 7 11 UD3 10 VC3 GND 8 9 UD4 n ABSOLUTE MAXIMUM RATINGS Supply Voltage ................................................… … … … … … ....................................... 18V DC Voltage Applied on other Pins .........… … … … … … … ..… ....................................... 18V Operating Temperature Range............................… … … … … … ......................... -20°C~70°C Storage Temperature Range .............................… … ..… … … ..................... - 65°C ~125°C n TEST CIRCUIT RO C 1M I OC S1 1 2 VOC VCC 16 NSL OC UD1 15 R8 3 V CS 1K 4 VOD VC1 14 CS 5 TD 13 VC2 12 6 TI UD3 11 C TI 2.2nF 7 TC CTC 1nF 8 I UD1 VC3 GND 10 UD4 9 R1 200 C1 0.1µF V CC IC 1 OD UD2 CTD 1nF I CC IUD2 R2 2K C2 0.1µF VC1 IC 2 IUD3 R3 2K C3 0.1µF VC2 IC3 IUD4 R4 33K C4 0.1µ F VC 3 AIC1804 2 AIC1804 n ELECTRICAL CHARACTERISTICS (Ta=25°C, unless otherwise specified.) PARAMETER TEST CONDITIONS SYMBOL MIN. TYP. MAX. UNIT VCC Pin Input Current in Normal VCELL=3.5V Mode ICC 17 26 µA VC1 Pin Input Current in Normal VCELL=3.5V Mode IC1 0.7 1.8 µA VC2 Pin Input Current in Normal VCELL=3.5V Mode IC2 0.4 1.0 µA VC3 Pin Input Current in Normal VCELL=3.5V Mode IC3 0.2 0.5 µA Vcc Pin Input Current in PowerDown Mode VCELL=2.3V ICC(PD) 2.2 4.0 µA VC1,VC2,VC3 Input Current in Power-Down Mode VCELL=2.3V IC(PD) 0.01 0.15 µA Overcharge Protection Voltage AIC1804A 4.32 4.35 4.38 4.27 4.30 4.33 AIC1804C 4.22 4.25 4.28 AIC1804D 4.17 4.20 4.23 AIC1804B VOCP V 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 Overcurrent Protection Voltage VCELL=3.5V VOIP 135 150 165 mV Overcharge Delay Time VCELL1=VOCP - 30mV →VOCP+30mV TOC 10 21 32 mS TOD 10 21 32 mS TOI1 7 15 23 mS VCELL2= VCELL3= VCELL4= 3.5V, CTC=1nF Overdischarge Delay Time VCELL1= 2.5V→ 2.3V VCELL2= VCELL3= VCELL4= 3.5V, CTD=1nF Overcurrent Delay Time (1) VCELL= 3.5V,0.15V<VCC VCS <0.3V,CTI=2.2nF 3 AIC1804 n ELECTRICAL CHARACTERISTICS (Ta=25°C, unless otherwise specified.) PARAMETER Overcurrent Delay Time (2) TEST CONDITIONS VCELL=3.5V, SYMBOL MIN. TYP. MAX. UNIT TOI2 2 4 6 mS TOI3 150 300 450 µS IOC 2.2 3.2 4.2 mA 0.3V<VCC-V CS<1.0V Overcurrent Delay Time (3) VCELL=3.5V, VCC– VCS>1.0V OC Pin Sink Current VCELL1=4.4V, VCELL2= VCELL3= VCELL4=3.5V, OC Pin Short to VCC OD Pin Output “H” Voltage VDH OD Pin Output “L” Voltage VDL Charge Detection Threshold Voltage VCELL=2.3V UD1 Pin Cell-Balancing Bleeding Current VCELL1=4.4V, UD2 Pin Cell-Balancing Bleeding Current VCELL2=4.4V, UD3 Pin Cell-Balancing Bleeding Current VCELL3=4.4V, UD4 Pin Cell-Balancing Bleeding Current VCELL4=4.4V, V V CC-0.15V V CC-0.03V 0.01 VCH 0.15 VCC+0.4 V CC+0.55 V V IUD1 6.5 9.3 12.1 mA IUD2 6.3 9.0 11.7 mA IUD3 6.2 8.8 11.4 mA IUD4 6.4 9.2 12.0 mA VCELL2= VCELL3= VCELL4=3.5V VCELL1= VCELL3= VCELL4=3.5V VCELL1= VCELL2= VCELL4=3.5V VCELL1= VCELL2= VCELL3=3.5V Note: VCELL means the battery cell voltage. Therefore, VCELL1 = VCC – V C1 VCELL2 = VC1 – V C2 VCELL3 = VC2 – V C3 VCELL4 = VC3 4 AIC1804 n TYPICAL PERFORMANCE CHARACTERISTICS Vcc Pin Power-Down Current vs. Supply Voltage Vcc Pin Input Current vs. Supply Voltage 2.2 Vcc Pin Input Current (µA) Vcc Pin Power-Down Current (µA) 22 20 18 16 14 10.4 Ta=25°C 2.0 1.8 1.6 1.4 1.2 1.0 11.2 12.0 12.8 13.6 14.4 15.2 6.0 16.0 6.4 6.8 Supply Voltage (V) Vcc Pin Power-Down Current (uA) Vcc Pin Input Current (µA) VCELL =3.5V 18 16 -10 0 10 20 30 40 50 60 8.8 9.2 2.6 VCELL=2.3V 2.4 2.2 2.0 1.8 1.6 -20 70 -10 0 Overdischarge Protection Voltage (V) AIC1804C 4.28 4.26 4.24 4.22 20 40 Temperature (°C) 20 30 40 50 60 70 Overdischarge Protection Voltage vs. Temperature Overcharge Protection Voltage vs. Temperature 0 10 Temperature (° C) 4.30 Overcharge Protection Voltage (V) 8.4 2.8 Temperature (°C) -20 8.0 3.0 20 4.20 7.6 Vcc Pin Power-Down Current vs. Temperature Vcc Pin Input Current vs. Temperature 22 14 -20 7.2 Supply Voltage (V) 60 70 2.42 2.41 2.40 2.39 2.38 2.37 2.36 -20 -10 0 10 20 30 40 Temperature (°C) 50 60 70 5 AIC1804 n TYPICAL PERFORMANCE CHARACTERISTICS (CONTINUED) Overcharge/Overdischarge Delay Time vs. Temperature Overcurrent Protection Voltage (V) 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) Overcurrent Protection Voltage vs. Temperature 152.0 26 22 20 18 16 14 -20 -10 0 10 20 30 40 50 60 70 Temperature(° C) Overcurrent Delay Time 1 vs. Temperature Overcharge Release Voltage vs. Temperature 4.08 Overcharge Release Voltage (V) 22 Overcurrent Delay Time 1 (mS) CTC /C TD=1nF 24 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 Temperature (o°C) 50 60 70 6 AIC1804 n BLOCK DIAGRAM CS 3 VCC VC1 VC2 VC3 UD1 16 14 Battery Voltage Sense Circuit 12 Wake-Up Control VCC+0.4V VCC-0.15V 10 Overcurrent Delay Circuit 15 VCC-0.3V 300 4 UD2 13 OD VCC-1V 350 UD3 11 Overdischarge Delay Circuit 400 UD4 Power-Down Control 2 OC Overcharge Delay Circuit 9 450 1.2V GND 8 7 5 TC 6 TD TI n PIN DESCRIPTIONS PIN 1: NSL- PIN 2: OC- PIN 3: CS- Input pin for cell number selection. Connect this pin to VCC for three-cell application and to GND for four-cell application. 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. PIN 4: OD - Output pin for control of discharge control M PIN 5: TD - Overdischarge delay time setting pin. PIN 6: TI - Overcurrent delay pin. PIN 7: TC - Overcharge delay time setting pin. PIN 8: GND - Ground pin. This pin is to be connected to the negative terminal of the battery cell BAT4. PIN 9: UD4- This pin is to be connected to the positive terminal of the battery cell BAT4 for cell-balancing bleeding function under overcharge condition. PIN10: VC3- Input pin for battery BAT4 voltage sensing. This pin is to be connected to the positive terminal of the battery cell BAT4. PIN11: UD3 - This pin is to time setting be connected to 7 AIC1804 PIN12: VC2 - PIN13: UD2 - the positive terminal of the battery cell BAT3 for cellbalancing bleeding function under overcharge condition. overcharge condition. PIN14: VC1 - Input pin for battery BAT3 voltage sensing. This pin is to be connected to the positive terminal of the battery cell BAT3. Input pin for battery BAT2 voltage sensing. This pin is to be connected to the positive terminal of the battery cell BAT2. PIN15: UD1 - This pin is to be connected to the positive ter PIN16: VCC - Power supply pin and input for battery BAT1 voltage sensing. This pin is to be connected to the positive terminal of the battery cell BAT1. This pin is to be connected to the positive terminal of the battery cell BAT2 for cell-balancing bleeding function under n APPLICATION INFORMATIONS THE OPERATION is immediately released when the voltage of the Initialization overdischarge cell becomes higher than the On initial power-up, such as connecting the overdischarge release voltage (V ODR) through battery pack for the first time to the AIC1804, the charging. AIC1804 enters the power-down mode. A charger must be applied to the AIC1804 circuit Overcurrent Protection to enable the pack. In normal mode, the AIC1804 continuously monitors the discharge current by sensing the voltage of CS pin. If the voltage VCC -V CS Overcharge Protection When the voltage of either of the battery cells exceeds the overcharge protection voltage (V OCP) beyond the overcharge delay time (TOC ) period, charging is inhibited by the turning-off of the charge control MOSFET M2. The overcharge delay time is set by the external capacitor C TC . Inhibition of charging is immediately released when the voltage of the overcharged cell becomes lower than overcharge release voltage (V OCR or VOCP -V HYS) through discharging. Overdischarge Protection exceeds the overcurrent protection voltage (V OIP) beyond the overcurrent delay time (TOI) period, the overcurrent protection circuit operates and discharging is inhibited by the turning-off of the discharge control MOSFET M1. Discharging must be inhibited for at least 256mS after overcurrent takes place to avoid damage to external control MOSFETs due to rapidly switching transient between BATT+ and BATTterminals. The overcurrent condition returns to normal mode when the load is released and the impedance between the BATT+ and BATTterminals is 20MΩ or higher. When the voltage of either of the battery cells The falls below the overdischarge protection voltage overcurrent detection levels (0.15V, 0.3V and (V ODP) beyond the overdischarge delay time 1.0V) and the three overcurrent delay time (TOI1, (TOD ) period, discharging is inhibited by the TOI2 and TOI3 ) corresponding to each overcurrent turning-off of the discharge control MOSFET M1. detection level. TOI1 is set by the external The overdischarge delay time is set by the capacitor CTI . TOI2 and TOI3 default to 4mS and external capacitor CTD . Inhibition of discharging 300µs respectively, and can not be adjusted due AIC1804 is provided with the three 8 AIC1804 to protection of external MOSFETs VCH ). DESIGN GUIDE Cell-Balancing Bleeding after Overcharge Cell Number Selection When either of the battery cells is overcharged, or four series cells application. For three-cell the cell-balancing application, NSL pin should be connected bleeding function to discharge the overcharged directly to VCC pin. For four-cell application, cell at about 9mA until the voltage of the NSL pin should be connected directly to GND overcharged BAT3 and BAT4 accomplish this function, pin. No. of Series Cells NSL Pin 3-cell Connected to VCC 4-cell Connected to GND The protection circuit for three-cell lithium-ion respectively. Inserting resistors along UD2 pin to battery pack is shown in application examples BAT2 positive terminal path and UD4 pin to Fig. 1. AIC1804 release provides cell voltage the decreases (V OCR to or The user must configure the AIC1804 for three overcharge VOCP-VHYS). Connecting UD1, UD2, UD3 and UD4 pins to the positive terminals of battery cells BAT1, BAT2, BAT4 positive terminal path can decrease the bleeding current. Setting the Overcharge and Overdischarge Delay Time Power-Down after Overdischarge The overcharge delay time is set by the external When overdischarge occurs, the AIC1804 will go capacitor CTC and the overdischarge delay time into power-down mode, turning off all the timing is set by the external capacitor CTD . The generation and detection circuitry to reduce the quiescent current to about 2.2µA (V CC =9.2V). In the unusual case where one battery cell is relationship between capacitance of the external capacitors and delay time is tabulated as below. CTC ‚C TD (nF) TOC ‚TOD (mS) 1 21 5 52 10 132 22 253 33 347 47 617 68 748 discharge 82 1004 control MOSFET M1 turns off and discharging is 100 1630 overdischarged while another one under overcharge condition, the AIC1804 will turn off all the detection circuitry except the overcharge detection circuit for the cell under overcharge condition. Charge Detection after Overdischarge When overdischarge occurs, the inhibited. However, charging is still permitted through the parasitic diode of M1. Once the charger is connected to the battery pack, the AIC1804 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 The delay time can also be approximately calculated by the following equations (if CTC , CTD ≤ 82nF) : TOC (mS) = 11.8 x CTC (nF) TOD (mS) = 11.8 x CTD (nF) Setting the Overcurrent Delay Time 1 The overcurrent delay time 1 (TOI1 ) at 0.15V < 9 AIC1804 VCC -VCS < 0.3V is set by the external capacitor resistance of the external MOSFET changes, CTI , while the overcurrent delay time 2 and 3 the overcurrent threshold current will change (TOI2 and TOI3) is fixed by IC internal circuit.The accordingly. relationship between capacitance of the external capacitor and delay time is tabulated as below. 1 4.8 Suppressing the Ripple and Disturbance from Charger 2.2 15.0 To suppress the ripple and disturbance from 3.3 18.8 5 23.6 6.8 31.0 10 61.8 CTI (nF) TOI (mS) charger, connecting R1 to R4 and C1 to C4 is recommended. Larger R1 will cause larger error of battery sense voltage. Controlling the Charge Control MOSFET Selection of External Control MOSFETs R5, R6, R7 and NPN transistor Q1 are used to Because the overcurrent protection voltage is overcharge does not occur, no current flows into preset, the threshold current for overcurrent OC pin and Q1 is turned off, then M2 is turned detection turn-on on. When overcharge occurs, current flows into resistance of the discharge control MOSFET M1. OC pin and Q1 is turned on, which turns off M2 The turn-on resistance of the external control in turn. is determined by switch the charge control MOSFET M2. If the MOSFETs can be determined by the equation: RON =VOIP/IT (I T is the overcurrent threshold Protection at CS Pin current). overcurrent R8 is used for protection of IC when charger is threshold current TI is designed to be 5A, the connected in reverse. The charge detection turn-on control function after overdischarge is possibly disabled MOSFETs must be 30mΩ. Users should be by larger value of R8. Resistance of 1KΩ is aware that turn-on resistance of the MOSFET recommended. For example, resistance of if the the external changes with temperature variation due to heat dissipation. It changes with the voltage between gate and source as well. (Turn-on resistance of a MOSFET increases as the voltage between gate and source decreases). Once the turn-on 10 AIC1804 n APPLICATION EXAMPLES R8 1K NSL VCC R1 16 C1 0.1µF 2 OC 3 CS 4 5 CTD 82nF + 6 + CTI 2.2nF 7 + CT C 82nF 8 UD1 15 14 TC 11 UD3 10 VC3 GND UD4 TI FUSE 1K C2 1K 0.1 µF 13 UD2 12 VC2 TD SI4435 M2 M1 BATT+ R2 VC1 OD SI4435 2N3906 Q1 1 BAT1 R3 1K C3 0.1µF R5 1M R6 1M BAT2 R7 1M R4 1K C4 0.1µF 9 BAT3 BATT- AIC1804 Fig. 1 Protection Circuit for Three-Cell Lithium-Ion Battery Pack n TIMING DIAGRAM l Overcharge and Overdischarge Protection (VCS=VCC ) <TO C TOC V BAT1 V OCP V OCP- V HYS VCELL VODR V BAT2 V BAT3 V BAT4 VODP TOD <TOD VOC VOD Hi-Z Hi-Z 0V VCC 0V 11 AIC1804 l Overcurrent Protection (VCELL =3.5V) <256ms >256ms VCC VCC- 0.15V VCC - 0.3V VCS VCC - 1V 0V TOI1 <TOI2 <T TOI3 OI1 VCC VOD 0V 256ms <256ms VOC Hi-Z n PACKAGE DIMENSIONS 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 A 1.27 (TYP) H 5.80 6.20 L 0.40 1.27 A1 l B C L 12