AIC1821 One-Cell Lithium-Ion Battery Protection IC n FEATURES n DESCRIPTION l Reduction in Board Size due to Package SOT-25 and Less Components. l Ultra-Low Quiescent Current at 7A (V CC =3.5V). l Ultra-Low Power-Down Current at 0.6A (V CC =2.2V). l Precision Overcharge Protection Voltage The AIC1821 battery protection IC is designed to protect lithium-ion battery from damage or degrading the lifetime due to overcharge, overdischarge, and/or overcurrent for one-cell lithium-ion battery powered systems, such as cellular phones. The ultra-small package and less required external components make it ideal to integrate the AIC1821 into the limited space of battery pack. Miniature External 4.35V 50mV for the AIC1821A 4.30V 50mV for the AIC1821B 4.25V 50mV for the AIC1821C l l l The accurate 50mV overcharging detection voltage ensures safe and full utilization charging. 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 50mV for the AIC1821D Built-in Delay Time Circuits for Overcharge, Over-discharge, and Overcurrent Protection. Load Detection Function during Overcharge Mode. Two Detection Levels for Overcurrent Protection. n APPLICATIONS l Protection IC for One-Cell Lithium-Ion Battery Pack. n TYPICAL APPLICATION CIRCUIT FUSE BATT+ BATTERY R1 100 5 VCC CS C1 0.1 F 2 3 M1 SI9926 4 GND R2 OD OC 100K 1 R3 AIC1821 10M BATTM2 SI9926 Protection Circuit for One-Cell Lithium-Ion Battery Analog Integrations Corporation 4F, 9 Industry E. 9th Rd, Science-Based Industrial Park, Hsinchu, Taiwan TEL: 886-3-5772500 FAX: 886-3-5772510 www.analog.com.tw DS-1821-00 012102 1 AIC1821 n ORDERING INFORMATION AIC1821-XC XXX PIN CONFIGURATION PACKING TYPE TR: TAPE & REEL BG: BAG SOT-23-5 TOP VIEW PACKAGE TYPE V: SOT-23-5 VCC CS 5 1 OC 4 2 3 GND OD OVERCHARGE PROTECTION A: 4.35V B: 4.30V C: 4.25V D: 4.20V Example: AIC1821-A CV TR a 4.35V version, in SOT-23-5 Package & Taping & Reel Packing Type n ABSOLUTE MAXIMUM RATINGS Supply Voltage....................................... ... ... ... ... ... ... .................................................... 18V DC Voltage Applied on other Pins .................. ... ... ... ... ... ... ... ... ... .............................. 18V Charger Voltage ................. ... ... ... ... ... ... ... ... .... ... ... ... ... ... ... ... ................................ 14V Operating Temperature Range Storage Temperature Range ........................................ ... ... ... ... ... .............. -40C~85C ............................ ... ... ... ... ... ... ..................... - 65C~125C n TEST CIRCUIT ICC R1 5 V CC 100 CS C1 0.1F R2 4 VCS 100K 2 VO D VCC 3 GND OD OC AIC1821 1 VO C R3 10M 2 AIC1821 n ELECTRICAL CHARACTERISTICS (Ta=25C, unless otherwise specified.) PARAMETER TEST CONDITIONS SYMBOL MIN. TYP. MAX. UNIT Supply Current VCC =3.5V ICC 7 11 A Power-Down Current VCC =2.2V, I PD 0.6 1.0 A Overcharge Protection Voltage AIC1821A 4.30 4.35 4.40 4.25 4.30 4.35 AIC1821C 4.20 4.25 4.30 AIC1821D 4.15 4.20 4.25 AIC1821B VOCP V Overcharge Hysteresis Voltage VHYS 230 300 370 mV Overdischarge Protection Voltage VODP 2.25 2.4 2.55 V Overdischarge Release Voltage VODR 2.85 3.0 3.15 V 180 200 220 mV 100 150 200 mS Overcurrent Protection Voltage VCC =3.5V VOIP Overcharge Delay Time VCC =VOCP-0.1 TOC VOCP + 0.1V Overdischarge Delay Time VCC = 2.6V 2.2V TOD 6 12 18 mS Overcurrent Delay Time (1) VCC =3.5V, 1V>VCS>0.2V TOI1 6 12 18 mS Overcurrent Delay Time (2) VCC =3.5V, VCS>1V TOI2 50 S OD Pin Output "H" Voltage VDH OD Pin Output "L" Voltage VDL 0.01 0.1 V 0.3 0.4 V Load Dectection Threshold Voltage VCC =VOCP - 50mV VLD Charge Detection Threshold Voltage VCC =2.4V VCH VCC-0.2 -0.45 VCC-0.02 -0.3 V V 3 AIC1821 n TYPICAL PERFORMANCE CHARACTERISTICS Supply Current vs. Supply Voltage Supply Current vs. Temperature 10 8.0 Ta=25 C Vcc=3.5V 9 Supply Current ( A) Supply Current (A) 7.6 7.2 6.8 8 7 6 6.4 2.8 3.0 3.2 3.4 3.6 3.8 4.0 5 -40 4.2 -20 0 Supply Voltage (V) Power-Down Current vs. Temperature Overcharge Protection Voltage (V) Power-Down Current (A) Vcc=2.2V 80 0.60 0.57 -20 0 20 40 60 4.34 AIC1821B 4.32 4.30 4.28 4.26 4.24 -40 80 -20 0 Temperature ( C) 20 40 60 80 Temperature ( C) Overdischarge Protection Voltage vs. Temperature Overcurrent Protection Voltage vs. Temperature 202 2.42 Overcurrent Protection Voltage (mV) Overdischarge Protection Voltage (V) 60 Overcharge Protection Voltage vs. Temperature 0.63 2.41 2.40 2.39 2.38 -40 40 4.36 0.66 0.54 -40 20 Temperature (C) -20 0 20 40 Temperature (C) 60 80 Vcc=3.5V 201 200 199 198 -40 -20 0 20 40 Temperature ( C) 60 80 4 AIC1821 n TYPICAL PERFORMANCE CHARACTERISTICS (Continued) Overdischarge Release Voltage vs. Temperature Overcharge Release Voltage vs. Temperature 3.10 Overdischarge Release Voltage (V) Overcharge Release Voltage (V) 4.10 AIC1821B 4.05 4.00 3.95 3.90 -40 -20 0 20 40 Temperature ( C) 60 3.05 3.00 2.95 2.90 -40 80 20 40 60 80 Overdischarge Delay Time vs. Temperature Overcharge Delay Time vs. Temperature 12 Overdischarge Delay Time (mS) Overcharge Delay Time (mS) 0 Temperature ( C) 145 140 135 130 125 -40 -20 -20 0 20 40 60 80 Temperature (C) 11 10 9 8 -40 -20 0 20 40 60 80 Temperature (C) Overcurrent Delay Time 1 vs. Temperature Overcurrent Delay Time 1(mS) 12 Vcc=3.5V 11 10 9 8 -40 -20 0 20 40 Temperature (C) 60 80 5 AIC1821 n BLOCK DIAGRAM Wake-up Control Enable -0.3V Load Detected CS 0.3V 4 0.2V Enable Overcurrent Delay Circuit 3 VCC 5 OD 1V Overdischarge Delay Circuit Power-down Control Overcharge Delay Circuit 1.2V GND 2 1 OC n PIN DESCRIPTIONS PIN 1: OC - PMOS open drain output for control of the charge control MOSFET M2. In normal mode, this PMOS turns on to pull the gate of the MOSFET M2 to high, then the MOSFET M2 turns on. When overcharge occurs, this PMOS turns off, then no current flows through R3 and the MOSFET M2 turns off. PIN 2: GND - Ground pin. This pin is to be connected to the negative terminal of the battery cell. PIN 3: OD - Output pin for control of the discharge control MOSFET M1. When overdischarge occurs, this pin goes low to turn off the MOSFET M1 and discharging is inhibited. PIN 4: CS - Input pin for current sensing. Using the sum of drain-source voltages of the MOSFET M1 and the MOSFET M2 (voltage between CS and GND), it senses discharge current during normal mode and detects whether charge current is present during powerdown mode. It also used to detect whether load is connected during overcharge mode. PIN 5: VCC - Power supply pin. This pin is to be connected to the positive terminal of the battery cell. 6 AIC1821 One-Cell Lithium-Ion Battery Protection IC n APPLICATION INFORMATIONS l THE OPERATION (V OIP) beyond the overcurrent delay time (TOI) Overcharge Protection period, When the voltage of the battery cell exceeds the overcharge protection voltage the overcurrent protection circuit operates and discharging is inhibited by the (V OCP) turning-off of the discharge control MOSFET M1. beyond the overcharge delay time (TOC ) period, The overcurrent condition returns to the normal charging is inhibited by the turning-off of the charge control MOSFET M2. The overcharge delay time is fixed to 100mS by IC internal circuit. The overcharge condition is released in two cases: impedance between the BATT+ and BATTterminals is 1M or higher. The AIC1821 is provided with the two overcurrent detection levels (0.2V and 1V) and 1. The voltage of the battery cell becomes lower than the overcharge release voltage (V OCR or VOCP- VHYS) through self-discharge. 2. mode when the load is released and the the two overcurrent delay time (TOI1 and TOI2) corresponding to each overcurrent detection level. The voltage of the battery cell falls below the overcharge protection voltage (V OCP) Load Detection after Overcharge and a load is connected. The load detection function after overcharge is When the battery voltage is above VOCP, the implemented by detecting the CS pin voltage. overcharge condition is never released even a Once a load is connected to the battery pack load is connected to the pack. after Overdischarge Protection When the voltage of the battery cell goes below the overdischarge protection voltage (V ODP) beyond the overdischarge delay time (TOD ) period, discharging is inhibited by the overcharge, discharge current flows through the parasitic diode of MOSFET M2 and there is a diode voltage drop between CS and GND. Load is determined to be connected to the pack if the CS pin voltage is above load detection threshold voltage (V LD ). turning-off of the discharge control MOSFET Power-Down after Overdischarge M1. The overdischarge delay time defaults to When overdischarge occurs, the AIC1821 will go 10mS. Inhibition of discharging is immediately into power-down mode, turning off all the timing released when the voltage of the battery cell generation and detection circuitry to reduce the becomes higher than overdischarge release quiescent current to 0.6A (V CC =2.2V). At the voltage (V ODR) through charging. same time, the CS pin is pull-high to VCC Overcurrent Protection through a high resistance resistor. In normal mode, the AIC1821 continuously Charge Detection after Overdischarge monitors the discharge current by sensing the When voltage of CS pin. If the voltage of CS pin control MOSFET M1 turns off and discharging is exceeds the overcurrent protection voltage inhibited. However, charging is still permitted Analog Integrations Corporation overdischarge occurs, 4F, 9 Industry E. 9th Rd, Science-Based Industrial Park, Hsinchu, Taiwan TEL: 886-3-5772500 FAX: 886-3-5772510 www.analog.com.tw the discharge DS-1821-00 012102 7 AIC1821 l through the parasitic diode of M1. Once the due to heat dissipation. It changes with the charger is connected to the battery pack, the voltage between gate and source as well. (Turn- AIC1821 immediately turns on all the timing on resistance of a MOSFET increases as the generation and detection circuitry. Charging is voltage between gate and source decreases). determined to be in progress if the voltage Once the turn-on resistance of the external between CS and GND is below charge MOSFET changes, the overcurrent threshold detection threshold voltage (V CH ). current will change accordingly. DESIGN GUIDE Selection of External Control MOSFETs Suppressing the Ripple and Disturbance from Charger Because the overcurrent protection voltage is To suppress the ripple and disturbance from preset, the threshold current for overcurrent charger, connecting R1, C1 to VCC pin is detection recommended. is determined by the turn-on resistance of the discharge control MOSFET M1. The turn-on resistance of the external control MOSFETs can be determined by the equation: RON =VOIP/ (2 x IT) (IT is the overcurrent threshold current). For example, if the overcurrent threshold current IT is designed to be 3A, the turn-on resistance of the external control MOSFETs must be 33m. Users should be aware that turn-on resistance of the MOSFET changes with temperature variation Protection at CS pin R2 is used for latch-up protection when charger is connected under overdischarge condition and overstress protection at reverse connecting of a charger. Larger value of R2 reduces the charger leakage current in overcharge mode, but possibly disables the charge detection function after overdischarge. Resistance of 100K is recommended. 8 AIC1821 n TIMING DIAGRAM l Overcharge and Overdischarge Protection TOC TOC VCC VOCP VOCP-VHYS VODR VODP TOD VOC VCC VOD VCC Hi-Z Hi-Z 0V charger connected l load connected charger connected load connected charger connected Overcurrent Protection (VCC=3.5V) VCC 1V VBATT0.2V 0V T OI1 <TOI1 VOD T OI2 VCC 0V VOC VCC 9 AIC1821 n PHYSICAL DIMENSIONS l SOT-23-5 (unit: mm) C D L H E 1 e A A2 MIN MAX A 1.00 1.30 A1 -- 0.10 A2 0.70 0.90 b 0.35 0.50 C 0.10 0.25 D 2.70 3.10 E 1.40 1.80 e A1 b l SYMBOL 1.90 (TYP) H 2.60 3.00 L 0.37 -- 1 1 9 SOT-23-5 MARKING Part No. AIC1821ACV AIC1821BCV AIC1821CCV AIC1821DCV Marking BL0A BL0B BL0C BL0D 10