MITSUMI Protection of Lithium Ion Batteries (three cells in series) MM1293 Protection of Lithium Ion Batteries (three cells in series) Monolithic IC MM1293 Outline This IC provides protection for lithium ion batteries in the event of overcharging, overdischarging and overcurrents. When anomalies occur during charging or at other times and excessive voltages are applied, after a certain time has elapsed for each cell an external FET switch is turned off (overcharging detection) ; and in order to prevent overdischarge of the battery during discharge, when the voltage of individual batteries falls below a fixed voltage, an external FET switch is turned off (overdischarging detection), and the IC is put into low-consumption current mode. When large currents flow due to a short-circuit or other cause, an external MOS switch is turned off (overcurrent detection). 3-Cell Protection ICs Rank A B C D E F G Overcharge Overcharge Overdischarge Overdischarge Overcurrent At overcurrent Overcurrent release detection voltage hysteresis voltage detection voltage resume voltage detection voltage detection conditions Load release 4.35V±50mV 200mV typ. 2.35V typ. 3.05V typ. 150mV typ. Pin 3 (DOHG pin) L H 250kΩ or more 4.25V±50mV 2.40V typ. 3.10V typ. Same as rank A Same as rank A Pin 4 (OL pin) H L Same as rank B Same as rank B none (several mV) Same as rank B Pin 3 (DOHG pin) L H 4.10V±50mV 2.35V typ. 3.00V typ. Same as rank A 200mV typ. Same as rank A Charging reset Features 1. Current consumption (overcharging) VCELL > VCELLU 125µA typ. 2. Current consumption (normal operation) VCELL < VALM 30µA typ. 3. Current consumption (overdischarge) VCELL < VCELLS 0.1µA max. 4. Overcharge detection voltage (-20 to +70°C) VCELL : L H 4.25V±50mV/CELL 5. Overcharge hystereis voltage VCELL : H L VCELLU-200mV/CELL typ. 6. Overcharge sensing dead time C=0.1µF 1.0S typ. 7. Overcharge sensing operation voltage VCELL : L H 4.10V±150mV/CELL 8. Overdischarge detection voltage VCELL : H L 2.40V/CELL typ. 9. Overdischarge sensing dead time C=0.1µF 1.0S typ. 10.Overcurrent detection voltage 0.15V typ. 11.Overcharge and overdischarve voltages as well as the overcurrent detection voltage can be changed upon request. Package SSOP-16 Applications Lithium ion battery pack for notebook computers Protection of Lithium Ion Batteries (three cells in series) MM1293 MITSUMI Block Diagram Pin Assignment 16 15 14 13 12 11 10 9 1 2 3 4 5 6 7 8 SSOP-16 1 OV 9 GND 2 CS 10 ML 3 DCHG 11 BATL 4 PF 12 MM 5 CDC 13 BATM 6 COL 14 MH 7 COV 15 BATH 8 MSW 16 VCC Protection of Lithium Ion Batteries (three cells in series) MM1293 MITSUMI Pin Assignment Pin no. Pin name Input/output Function Overcharge detection output pin NPN transistor open collector output; normally high impedance, goes to L level on overdischarge Overcurrent detection pin Monitors equivalent load current through source-drain voltage drop of discharge-controlling FET, and at or above the overcurrent detection voltage sets the DCHG pin to "H" and turns off the discharge-controlling FET. Following overcurrent detection, current is passed from this pin, and if the load is decreased, the overcurrent mode is canceled. Through this action there is a temporary consumption current (at the VCC pin) of approx. 1 mA on resumption of discharge and detection of overdischarge. This function is disabled in overdischarge mode. Pin driving the discharge-controlling FET (P-ch) Normally "L"; on overdischarge set to "H" Output pin for overdischarge detection signals Overdischarge detection pin When the overdischarge detector detects overdischarge at the open collector output of the NPN transistor, this pin is turned on. A delay is provided by setting a dead time until discharge ends, so that by utilizing a reset or other signal from a CPU or some other controlling device, the equipment can be put into standby mode. Pin to set the dead time for overdischarge detection By connecting a capacitor between the CDC pin and GND, a dead time can be set. Pin to set the dead time for overcurrent detection Pin to set the dead time for overcurrent detection By connecting a capacitor between the COL pin and GND, a dead time can be set. If NC, protection is triggered in a short amount of time; the dead time should be set according to the application. Pin to set the dead time for overcharge detection By connecting a capacitor between the COV pin and GND, a dead time can be set. Pin to switch the cell voltage monitor on/off GND: monitor on, VCC: monitor off The cell voltage monitor converts the different cell voltages to a GNDreference voltage and outputs it from the ML, MM and MH pins. 1 OV Output 2 CS Input 3 DCHG Output 4 PF Output 5 CDC Input 6 COL Input 7 COV Input 8 MSW Input 9 GND Input 10 ML Output 11 BATL Input 12 MM Output 13 BATM Input 14 MH Output 15 BATH Input Pin for input of H cell high-side voltage 16 VCC Input Power supply input pin The same potential as the BATH pin should be input Absolute Maximun Ratings Ground pin Monitor output pin for the L cell voltage Pin for input of L cell high-side voltage and M cell low-side voltage Monitor output pin for the M cell voltage Pin for input of M cell high-side voltage and H cell low-side voltage Monitor output pin for the H cell voltage (Ta=25°C) Item Symbol Ratings Units Storage temperature TSTG -40~+125 °C Operating temperature TOPR -20~+70 °C Charge voltage VBAT max. 18 V Power supply voltage VCC max. 18 V Voltage applied to OV pin VOV max. 18 V Allowable loss Pd 300 mW Protection of Lithium Ion Batteries (three cells in series) MM1293 MITSUMI Recommended Operating Conditions Item Symbol Ratings Units Operating temperature TOPR -20~+70 °C Operating voltage VOPR +2~+18 V Electrical Characteristics (Except where noted otherwise, Ta=25°C, VCC=15V, VCELL=VBATH=VBATM=VBATL) Item Symbol Measurement conditions Consumption current (VCC pin) 1 ICC1 VCELL=4.4V 125 250 µA Consumption current (VCC pin) 2 ICC2 VCELL=3.5V 30 60 µA Consumption current (VCC pin) 3 ICC3 VCELL=2.2V 0.1 µA Consumption current (BATH pin) 1 IBATH1 VCELL=4.4V 11 22 µA Consumption current (BATH pin) 2 IBATH2 VCELL=3.5V 5 10 µA Consumption current (BATH pin) 3 IBATH3 VCELL=2.2V 2 4 µA BATM pin input current 1 IBATM VCELL=3.5V ±300 nA BATM pin input current 2 IBATMA VCELL=4.4V 0 µA BATL pin input current 1 IBATL VCELL=3.5V ±300 nA BATL pin input current 2 IBATLA VCELL=4.4V Overcharge detection voltage VCELLU Ta=-20~+70°C, VCELL : 3.7V VCELLO VCELL : 4.5V Overcharge detection release voltage Overcharge sensing dead time tOV Overcharge sensing operation voltage VALM Min. Typ. Max. Units -0.6 4.5V 3.7V COV=0.1µF -0.3 -0.6 -0.3 0 µA 4.20 4.25 4.30 V VCELLU VCELLU VCELLU -260mV -200mV -140mV V 0.5 1.0 1.5 S VCELL : 3.5V 4.4V 3.95 4.10 4.25 V Overdischarge sensing hysteresis voltage VALM VCELL : 4.4V 3.5V 120 200 300 mV Overdischarge detection voltage VCELLS VCELL : 3.5V 2.0V 2.30 2.40 2.50 V Discharge resume voltage VCELLD VCELL : 2.0V 3.5V 2.95 3.10 3.25 V VCELLD-VCELLS 490 700 910 mV 0.5 1.0 1.5 S Overdischarge sensing hysteresis voltage VCSD Overdischarge sensing dead time tCDC1 CCDC=0.1µF Overdischarge reset dead time tCDC2 CCDC=0.1µF, VCS=VCC+0.3V 7 mS Overcurrent detection voltage VOC VCC-VCS, DCHG 0.135 0.150 0.165 V Overcurrent sensing dead time tCOL1 CCOL=0.001µF, DCHG 5 10 15 mS Overcurrent reset dead time tCOL2 CCOL=0.001µF, DCHG 5 10 15 mS Overcurrent sensing delay time tCOL3 CCOL=0, DCHG 150 µS Overcurrent reset delay time tCOL4 CCOL=0, DCHG 150 µS Open-load condition 250kΩ Overcurrent protection release DCHG pin source current ISODCH VCELL < VCELLS, SW1 : A, VDCHG=VCC -1.8V 20 µA DCHG pin sync current ISIDCH VCELL > VCELLS, SW1 : A, VDCHG=0.8V 20 µA DCHG pin output voltage H VTHDCH VCC -VDCHG, ISO=20µA, SW1 : B 1.8 V DCHG pin output voltage L VTHDCL VDCHG -GND, ISI=-20µA, SW1 : B 0.8 V OV pin sync current ISIOV VOV=0.4V, Ta=-20~+70°C 0.2 mA PF pin sync current ISIPF VPF=0.4V, Ta=-20~+70°C 10 µA Protection of Lithium Ion Batteries (three cells in series) MM1293 MITSUMI Timing Chart Overcharge Charging off Overcharge detection voltage Overcharge detection cancel voltage Cell voltage COV pin tOV Sensing dead zone Pin OV (pulled up) Overcharge state Normal state Overdischarge Discharge off Discharge resume voltage Cell voltage Overdischarge detection voltage CDC pin tCDC1 Sensing dead zone tCDC2 Reset dead zone DCHG pin Overdischarge state Normal state Pin PF (pulled up) Overcurrent Current passed from pin CS Load released CS pin COL pin tCOL Sensing dead zone tCOL Reset dead zone DCHG pin Normal state Overcurrent state Normal state Protection of Lithium Ion Batteries (three cells in series) MM1293 MITSUMI Application circuits Characteristics Overcharge, overdischarge sensing dead time Overcurrent dead time 100m Dead time t (s) Dead time t (s) 1 100m 10m 1m 100P 1000P 0.01µ Capacitance C (F) 0.1µ 10m 1m 10P 100P 0.001µ 0.01µ Capacitance C (F) Note : The above characteristics are representative and are not guaranteed.