MM1177

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) 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) 4.0~15.0V 100µA typ. 30µA typ. 4.5mA typ. 1177AF : 3.275V±75mV 1177BF : 3.0V±70mV 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 1 2 8 7 6 5 3 4 5 1 2 3 4 6 7 SOP-8C 8 N.C GND NC OUT2 OUT1 BATT N.C VIN MITSUMI Charge and discharge control for coin-type lithium batteries and manganese dioxide lithium batteries MM1177 Block Diagram Absolute Maximum Ratings Item Storage temperature Operating temperature input voltage Charging voltage Allowable power dissipation Charging current Discharging current Symbol TSTG TOPR VIN max. VBAT max. PD IBATT IL Rating -40~+125 -20~+70 18 3.5 300 10 1 Units °C °C V V mW mA mA Electrical Characteristics Item Input voltage operation range Current consumption 1 Current consumption 2 Charging current (limiter current) Limiter mode off 1177AF 1177BF Charging OFF voltage 1177AF 1177BF Current consumption (battery) Leak current when discharging is prohibited Voltage when discharging is prohibited Voltage drop between battery and output OUT2 pin voltage (Unless otherwise specified Ta=25°C, VIN=12.0V) Measurement Conditions during charging (constant voltage charge) charging off VIN=4V~15V, VBATT=2V IBATT=4mA IBATT=0mA, Ta=-20~+70°C IL=100µA, VBATT=3V VIN=0V or open VBATT=3.35V after VIN=0FF IL=100µA, VBATT=3V VCELL=3V 2.85 1.60 1.75 75 2.92 4.0 3.00 2.70 3.20 3.275 3.35 2.93 3.00 5 3.07 8 0.1 1.90 100 3.00 Min 4.0 100 30 4.5 Typ. Max. Units 15.0 180 45 5.0 V µA µA mA V V V µA µA V mV V Symbol VINOPR IIN1 IIN2 IBATT VICOFF VCHOFF IBA1 IBA2 VOOFF VCEOUT VOUT2 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 1. Charging current over 4mA Application Example 2 2. Charging current under 4mA Charging Characteristics Battery voltage-Charging current characteristics Charging current Application example 1 Battery voltage-Charging current characteristics Charging current Application example 2 Charging current (MAX value) Application example 1 Battery voltage 3.275V Vanadium lithium battery (MM1177A) Battery voltage 2.8V 3V Manganese dioxide lithium battery (MM1177B)