IC for Control of Lithium-ion Betteries Charging MM1438 MITSUMI IC for Control of Lithium-ion Betteries Charging Monolithic IC MM1438 Outline This IC is used to control charging of lithium-ion batteries consisting of a single cell. It is a modification of the previous MM1332 charging-control IC, with improved charging voltage accuracy and a smaller package. Features 1. Charging voltage accuracy (Ta=25°C) 2. Charging voltage accuracy (Ta=0 to 50°C) 3. Consumption current (charging on) 4. Consumption current (charging off) 5. Low-voltage detection 6. Leakage current between CEL and CS ±25mV/cell ±30mV/cell 250µA typ. 2µA typ. 2.15V typ. 1µA max. Package VSOP-8B Applications IC for control of lithium-ion batteries charging. Pin Assignment 8 1 7 2 6 3 VSOP-8B 5 4 1 GND 2 LV 3 SW2 4 SW1 5 VCC 6 EXT 7 CEL 8 CS IC for Control of Lithium-ion Betteries Charging MM1438 MITSUMI Block Diagram Pin Description Pin No. Pin name I/O 1 GND Input 2 LV Output 3 SW2 Input 4 SW1 Input 5 VCC Input 6 EXT Output 7 CEL Input Pin Description Ground pin Low voltage detection circuit output pin ON with NPN-Tr open collector output at low voltage Low voltage detection circuit ON/OFF control input pin SW2 = VCC: OFF, SW2 = GND: ON ON/OFF control input pin for the IC SW1 = VCC: OFF, SW1 = GND: ON Power supply input pin Charging control output pin Controls external PNP-Tr to control charging. Battery voltage input pin Detects battery voltage and controls rated voltage to the prescribed voltage value. Current detection pin 8 CS Input Detects current by drop in external resistor voltage and controls rated current. Current value can be set at 0.1V/R1 typ. IC for Control of Lithium-ion Betteries Charging MM1438 MITSUMI Absolute Maximum Ratings (Ta=25°C) Item Symbol Ratings Unit Storage temperature TSTG -40~+125 °C Operating temperature TOPR -20~+70 °C Power supply voltage VCC max. -0.3~+18 V CFL pin input voltage VCEL max. -0.3~+13 V SW input voltage VSW -0.3~VCC+0.3 V Allowable loss Pd 300 mW Recommended Operating Conditions Item Symbol Ratings Unit Operating temperature TOPR -20~+70 °C Charging control operating voltage VOPR 2.5~+17 V Note: Operating voltage minimum value is during rated current control. Electrical Characteristics (Except where noted otherwise, Ta=25°C, VCC=5V, SW3 : A, SW6 : A, SW7 : A) Item Symbol Measurement conditions Min. Typ. Consumption current 1 ICC1 VSW1=VSW2=0V (Charge : ON) 250 Consumption current 2 ICC2 VSW1=VSW2=VCC (Charge : OFF) 2 Ta=25°C 4.100 4.125 Output voltage 1 VO1 Output voltage 2 VO2 Ta=0~50°C 4.095 4.125 Current limit VCL 90 100 Inflow current between 3.0 5.0 ICEL1 CEL-CS during operation Leak current between CEL-CS ICEL2 VCC=0V or OPEN 0.01 SW1 input current ISW1 20 SW1 input voltage L VL1 Charge : ON -0.3 SW1 input voltage H VH1 Charge : OFF VCC-0.1 Low voltage detection voltage LV 2.0 2.15 SW2 input current ISW2 20 SW2 input current L VL2 Low voltage detection circuit: ON -0.3 SW2 input current H VH2 Low voltage detection circuit: OFF VCC-1.0 Low voltage detection ILV output leak current Low voltage detection ISINK=1mA 0.2 VLV output saturation voltage EXT pin inflow current IEXT 10 20 EXT pin output voltage VEXT For no load 0.3 Note 1: Please insert a capacitor of several µF between power supply and ground when using. Max. Unit 400 µA 10 µA 4.150 V 4.155 V 110 mV 7.0 µA 1 30 2.0 VCC+0.3 2.3 30 2.0 VCC+0.3 µA µA V V V µA V V 0.5 µA 0.4 V VCC-0.3 mA V Note 2: Be sure that CS pin potential does not fall below -0.5V. Note 3: If the IC is damaged and control is no longer possible, its safety can not be guaranteed. Please protect with something other than this IC. MITSUMI Measuring Circuit IC for Control of Lithium-ion Betteries Charging MM1438 IC for Control of Lithium-ion Betteries Charging MM1438 MITSUMI Measurement Procedures (Except where noted otherwise, Ta=25°C, VCC=5V, SW3 : A, SW6 : A, SW7 : A) Item Consumption current 1 Consumption current 2 Output voltage Current limit Inflow current between CEL-CS during operation Leak current between CEL-CS SW1 input current SW1 input voltage Measurement Procedures V3 = VCC, V4 = 0V. Next, measure A5 current value Icc1 when V3 is changed from VCC 0V. V3 = Vd = VCC. Measure A6 current value ICC2 at this time. V3 = VCC, V4 = 0V. Measure T7 voltage VO at this time. V3 = Vcc, V4 = 0V. Set V7 voltage 1V lower than T7 (output voltage) potential and set SW7 to B. Measure T8 voltage VCL at this time. V3 = VCC, V4 = 0V, SW6: C. V7 = 4.5V, SW7: B. Measure A7 current value ICEL1 at this time. V3 = V4 = VCC = 0V, SW6: C. V7 = 4.5V, SW7: B. Measure A7 current value ICEL2 at this time. Measure A4 current value ISW1 when V4 = 0V. V3 = VCC. Charge: ON (VL1) when V4 potential is varied and T7 voltage is the prescribed output voltage; Charge OFF (VH1) when 0 ~ 0.05V. V3 = V4 = 0V. Set V7 voltage 1V lower than T7 (output voltage) potential, and Low voltage detection voltage SW7: B. Next gradually lower V7 voltage; V7 voltage is LV when A7 current value is within ±10µA. SW2 input current Measure A3 current value ISW2 when V3 = 0V. V4 = 0V, V7 = 1V, SW7: B. Low voltage detection circuit: ON (VL2) when V3 SW2 input voltage voltage is varied and A7 current value is within ±10µA; low voltage detection circuit: OFF (VH2) otherwise. Low voltage detection output leak current Low voltage detection output saturation voltage V3 = VCC, V4 = 0V. Measure A2 current value ILV when V3 is changed from Vcc 0V. V3 = V4 = 0V. SW3: B, SW7: B. Measure T2 voltage VLV when V7 voltage is 0V. EXT pin inflow current V3 = V4 = 0V. SW6: B, SW7: B, V6 = 4V, V7 = 3V. Measure A6 current value IEXT. EXT pin output voltage V3 = V4 = 0V. SW6: C, SW7: B. T6 voltage when V7 = 3V and V7 = 5V is VEXT. IC for Control of Lithium-ion Betteries Charging MM1438 MITSUMI Timing Chart Battery connection and SW1: ON VCC 0 ON OFF SW1 0 ON Rated voltage mode OFF CEL 0 100mV Charging OFF Charging ON Normal charging CS 0 H LV 0 Rated current mode L CEL 0 Charging OFF CS Battery low voltage (2V or less) 0 LV L 0 (SW2 : L) Application Circuit IC for Control of Lithium-ion Betteries Charging MM1438 MITSUMI Characteristics Output voltage vs Power supply voltage (Ta=25°C) 4.10 0 5 10 15 (VCC=5V) 4.15 Output voltage (V) Output voltage (V) 4.15 4.05 Output voltage vs Ambient temperature 4.10 4.05 -25 18 Power supply voltage (V) CS pin voltage vs Power supply voltage 100 95 0 5 10 15 3 2 1 0 15 20 25 LV pin inflow current (mA) (Ta=25°C,VCC=5V) EXT pin voltage (V) 4 3 2 1 0 0 5 10 15 20 25 EXT pin inflow current (mA) 0 25 50 75 (Ta=25°C,VCC=5V, at low voltage detection) 150 100 50 0 2 2.1 2.2 2.3 Output voltage (V) EXT pin voltage vs EXT pin inflow current 5 95 200 CS pin voltage (mV) LV pin voltage (V) 4 10 100 CS pin voltage vs Output voltage (Ta=25°C) 5 105 Ambient temperature (°C) LV pin voltage vs LV pin inflow current 0 75 (VCC=5V) 90 -25 18 Power supply voltage (V) 5 50 110 CS pin voltage (mV) CS pin voltage (mV) 105 90 25 CS pin voltage vs Ambient temperature (Ta=25°C) 110 0 Ambient temperature (°C) 30 2.4 2.5