MM1251B

MITSUMI Remaining Battery Power Display MM1251, MM1252, MM1253 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 MM1251 MM1252 MM1253 Light Off Light On Light Off Low Power Flashing Flashing Flashing ±30mV ±30mV ±9mV Absolute Maximum Ratings Item Storage temperature Operating temperature Input voltage (Ta=25°C) Rating -40~+125 -20~+70 -0.3~+3 -0.3~+7 300 Unit °C °C V V mW Output Terminal Applied Voltage Allowable loss MITSUMI Remaining Battery Power Display MM1251, MM1252, MM1253 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 MM1251 MM1253A MM1252A MM1252B MM1251A MM1253A MM1251B VD VS=1V 0.5V MM1251 MM1252 0.82 Min. Typ. Max. Unit 25 0.15 0.75 0.15 25 0.85 40 0.25 0.1 0.25 40 0.88 µA mA mA mA µA V V PPM/°C 50 100 -20 60 0.4 0.3 150 1 Rank A 0.65 0.75 mV mV nA nA V V mA mA µA V Current consumption 1 ICC1 VCT=0.4V Current consumption 2 ICC2 VS=0.8V, VCT=0.4V Detection voltage VHYS < 0.1V = V/ T MM1253 0.841 0.85 0.859 ±200 25 50 -60 20 0.2 0.1 5 -40 40 0.3 0.2 10 100 Detection voltage temperature factor HYS pin saturation voltage 1 HYS pin saturation voltage 2 CT pin charge current CT pin discharge current CT pin threshold value H CT pin threshold value L Output sink current Output saturation voltage Output leak current Operating limit voltage VHYS1 VHYS2 ICTS ICTO VCTH VCTL IOUT IOUTL ILE VOPR IHYS=5µA IHYS=25µA VCT=0.1V VCT=0.4V VCT=0.1 0.4, VO < 0.1V = VCT=0.4 0.1, VO > 0.1V = VCR=0.4V VCT=0.4, IOUT=1mA VS=1V, VOUT=5V VS=0.8 VCCVOUT > 0.4V VCC 0.5V Rank B VS=0.8 Step-up operation limit voltage VOPL VCC=0.1V Voltage limit for maintaining LED flashing 0.85 0.95 V MITSUMI Remaining Battery Power Display MM1251, MM1252, MM1253 MM1251A /MM1253A Application Circuit Timing Chart VCC VD CT unsettled OUT MITSUMI Remaining Battery Power Display MM1251, MM1252, MM1253 MM1251B Application Circuit Timing Chart VCC VD CT unsettled OUT MITSUMI Remaining Battery Power Display MM1251, MM1252, MM1253 MM1252A Application Circuit Timing Chart VCC VD CT unsettled OUT MITSUMI Remaining Battery Power Display MM1251, MM1252, MM1253 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. Flashing interval Off interval Inductor Value-Oscillation Frequency Characteristics (reference data) Oscillation frequency (kHz) VCC 500 300 200 100 70 50 30 20 10 100 VCC=0.90V VCC=0.95V VCC=1.00V 200 300 500 700 1000 Oscillation frequency Flash Cycle Inductor value (µH) Note : The above data are reference values. Please set constants using a ±50% variance.