MITSUMI Charge and discharge control for coin-type lithium batteries and manganese dioxide lithium batteries MM1177 Charge and discharge control for coin-type lithium batteries and manganese dioxide lithium batteries Monolithic IC MM1177 Outline This IC controls constant current charging and excess discharge for coin-shaped vanadium lithium batteries and manganese dioxide batteries. It performs constant current charging, stops charging at set voltages, and prevents excess discharging. When the voltage falls bellow a set level, it prohibits discharges and reduces IC current consumption nearly to zero. Features During charging 1. Input voltage range 2. Current consumption (during constant current charging) 3. Current consumption (when charging is off) 4. Charging current 5. Charging shut-off voltage (Ta=-20~+70°C) 4.0~15.0V 100µA typ. 30µA typ. 4.5mA typ. 1177AF : 3.275V±75mV 1177BF : 3.0V±70mV During discharging 1. Discharging shut-off voltage 2. Current consumption (IL-100µA, VBATT=3V) 3. Leak current during discharge shut-off 4. Voltage drop between battery and output (IL=100µA, VBATT=3V) 1.75V±0.15V 5µA typ. 0.1µA max. 2.92V typ. Package SOP-8C (MM1177AF, MM1177BF) Applications 1. coin-shaped vanadium lithium batteries 2. Monitors and controls charging and discharging for and manganese dioxide batteries. Pin Assignment 8 1 7 2 6 3 SOP-8C 5 4 1 N.C 2 GND 3 NC 4 OUT2 5 OUT1 6 BATT 7 N.C 8 VIN MITSUMI Charge and discharge control for coin-type lithium batteries and manganese dioxide lithium batteries MM1177 Block Diagram Absolute Maximum Ratings Item Symbol Rating Units Storage temperature TSTG -40~+125 °C Operating temperature TOPR -20~+70 °C input voltage VIN max. 18 V Charging voltage VBAT max. 3.5 V Allowable power dissipation PD 300 mW Charging current IBATT 10 mA Discharging current IL 1 mA Electrical Characteristics (Unless otherwise specified Ta=25°C, VIN=12.0V) Item Symbol Input voltage operation range VINOPR Current consumption 1 IIN1 during charging (constant voltage charge) Current consumption 2 IIN2 charging off Charging current (limiter current) IBATT VIN=4V~15V, VBATT=2V VICOFF IBATT=4mA VCHOFF IBATT=0mA, Ta=-20~+70°C Current consumption (battery) IBA1 IL=100µA, VBATT=3V Leak current when discharging is prohibited IBA2 Voltage when discharging is prohibited VOOFF after VIN=0FF Voltage drop between battery and output VCEOUT IL=100µA, VBATT=3V OUT2 pin voltage VOUT2 VCELL=3V Limiter mode off 1177AF 1177BF Charging OFF voltage 1177AF 1177BF Measurement Conditions Min Typ. Max. Units 4.0 15.0 V 100 180 µA 30 45 µA 4.5 5.0 mA 4.0 3.00 V 2.70 3.20 3.275 3.35 V 2.93 3.00 3.07 V 5 8 µA 0.1 µA 1.75 1.90 V 75 100 mV 2.92 3.00 V VIN=0V or open VBATT=3.35V 1.60 2.85 Note : Do not connect the OUT2 pin to the load; it does not have current supply capability. To delay discharge prohibition, or suppress discharge prohibition caused by noise, connect a capacitor between the OUT2 pin and GND. MITSUMI Charge and discharge control for coin-type lithium batteries and manganese dioxide lithium batteries MM1177 Operation Outline The constant current, constant voltage charging control charges at a constant current of 4.5mA, until battery capacity reaches 0%~90%. It then switches to constant voltage control and sets the charge current to "0" when 100% charged. Output impedance is set at about 50Ω so charge current gradually drops and eventually reaches 0mA. The charging current maximum value is set by battery capacitance. Therefore, When the value falls below 4.5mA, insert a resistor (R) in series in order to lower charging current value. The discharging control has a built-in switching circuit between the battery and output. After switching off during excess discharge, all circuit operations are prohibited. Operation reset is achieved by resuming charging. In the event of an output short, output current is limited (about 5mA~10mA) by the internal switch function. This reduces the risk of battery heat emission caused by an output short. Also, the switching circuit and the battery voltage monitoring switch are on different systems. This means that the discharge output (OUT1) will not prohibit discharge even during a short, and noise from the output load section will not affect the detection circuit (OUT2). Application Example Application Example 1 Application Example 2 1. Charging current over 4mA 2. Charging current under 4mA Charging Characteristics Application example 1 Battery voltage 3.275V Vanadium lithium battery (MM1177A) Battery voltage-Charging current characteristics Charging current Charging current Battery voltage-Charging current characteristics Application example 2 Application example 1 Charging current (MAX value) Battery voltage 2.8V 3V Manganese dioxide lithium battery (MM1177B)