Remaining Battery Power Display MM1251, MM1252, MM1253 MITSUMI Remaining Battery Power Display Monolithic IC MM1251, MM1252, MM1253 Outline This IC detects battery voltage and displays the power remaining in the battery. Display of the battery's remaining power is an indispensable function for portable equipment. The use of this IC makes this display easily achievable. The usual method of display of remaining battery power, as in the MM1206, is three marks lighting up in sequence on an LED or other display. This IC, however, uses only one light to display the remaining battery power, resulting in lower cost. Features 1. 2. 3. 4. Adjustable flashing speed Adjustable detection voltage supports all settings Adjustable hysteresis voltage enables response to large ripple settings High precision voltage detection (MM1253) enables support of sets using nickel cadmium and other batteries 5. The LED can be lit up by the voltage from one battery (type of special built-in step-up circuit : rank B) Package SOP-8D (MM1251AF, MM1251BF, MM1252AF, MM1252BF, MM1253AF) Series Description Display Pattern Detection Precision Normal Low Power MM1251 Light Off Flashing ±30mV MM1252 Light On Flashing ±30mV MM1253 Light Off Flashing ±9mV Absolute Maximum Ratings (Ta=25°C) Item Rating Unit Storage temperature -40~+125 °C Operating temperature -20~+70 °C Input voltage -0.3~+3 V Output Terminal Applied Voltage -0.3~+7 V Allowable loss 300 mW Remaining Battery Power Display MM1251, MM1252, MM1253 MITSUMI Electrical Characteristics Item (Unless otherwise specified Ta=25°C, Vc=1.5V, Vs=0.8V) (Applicable to all models when the model name is left blank.) Symbol Measurement Conditions VS=1.0V Current consumption 1 ICC1 VCT=0.4V Min. Typ. Max. Unit MM1251 25 40 µA MM1252A 0.15 0.25 mA MM1252B 0.75 0.1 mA 0.15 0.25 mA 25 40 µA 0.85 0.88 V MM1253 0.841 0.85 0.859 V MM1253A MM1251A Current consumption 2 ICC2 VS=0.8V, VCT=0.4V MM1253A MM1251B Detection voltage VD VS=1V 0.5V VHYS <= 0.1V MM1251 MM1252 0.82 V/ T Detection voltage temperature factor ±200 PPM/°C HYS pin saturation voltage 1 VHYS1 IHYS=5µA 25 50 mV HYS pin saturation voltage 2 VHYS2 IHYS=25µA 50 100 mV CT pin charge current ICTS VCT=0.1V -60 -40 -20 nA CT pin discharge current ICTO VCT=0.4V 20 40 60 nA CT pin threshold value H VCTH VCT=0.1 0.4, VO <= 0.1V 0.2 0.3 0.4 V CT pin threshold value L VCTL 0.1 0.2 0.3 V Output sink current IOUT VCT=0.4 0.1, VO >= 0.1V VCR=0.4V 5 10 Output saturation voltage IOUTL VCT=0.4, IOUT=1mA Output leak current ILE VS=1V, VOUT=5V Operating limit voltage VOPR VS=0.8 VCCVOUT > 0.4V VS=0.8 Step-up operation limit voltage VOPL VCC=0.1V 100 mA 150 mA 1 µA Rank A 0.65 0.75 V Rank B 0.85 0.95 V VCC 0.5V Voltage limit for maintaining LED flashing Remaining Battery Power Display MM1251, MM1252, MM1253 MITSUMI MM1251A /MM1253A Application Circuit Timing Chart VCC VD CT OUT unsettled Remaining Battery Power Display MM1251, MM1252, MM1253 MITSUMI MM1251B Application Circuit Timing Chart VCC VD CT OUT unsettled Remaining Battery Power Display MM1251, MM1252, MM1253 MITSUMI MM1252A Application Circuit Timing Chart VCC CT OUT VD unsettled Remaining Battery Power Display MM1251, MM1252, MM1253 MITSUMI Step-up (Rank B) Type Inductor Values This circuit allows step-up for LED lighting even when low only. The LED repeats On/Off at high frequency, but to the human eye it appears as if the LED is lit. Therefore, we do not recommend the use of this step-up circuit in other circuits. VCC Oscillation frequency Flash Cycle Inductor Value-Oscillation Frequency Characteristics (reference data) Oscillation frequency (kHz) Flashing interval Off interval 500 300 200 100 70 50 30 VCC=0.90V VCC=0.95V VCC=1.00V 20 10 100 200 300 500 Inductor value (µH) Note : The above data are reference values. Please set constants using a ±50% variance. 700 1000