MAX871 MAXIM [Maxim Integrated Products], MAX871 Datasheet
MAX871
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MAX871 Summary of contents
Page 1
... The ultra-small MAX870/MAX871 monolithic, CMOS charge-pump inverters accept input voltages ranging from +1.4V to +5.5V. The MAX870 operates at 125kHz, and the MAX871 operates at 500kHz. Their high efficien- cy (90%) and low operating current (0.7mA for the MAX870) make these devices ideal for both battery-pow- ered and board-level voltage-conversion applications. ...
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... Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V = +5V 1µF (MAX870 0.33µF (MAX871 are +25°C.) ...
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... CAPACITANCE ( F) MAX870 OUTPUT RESISTANCE vs. TEMPERATURE 5.0 5.5 -40 - TEMPERATURE (°C) MAX871 OUTPUT RESISTANCE vs. TEMPERATURE 4.5 5.0 -40 - TEMPERATURE (°C) MAX870 OUTPUT VOLTAGE vs. OUTPUT CURRENT 0 -0 2.0V -1 3.3V -2 ...
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... OUTPUT CURRENT (mA 20mV/div, AC COUPLED (MAX870) Figure 1. Test Circuit PUMP FREQUENCY vs. TEMPERATURE 600 V = 3.3V OR 5.0V, MAX871 IN 550 500 V = 1.5V, MAX871 450 IN 400 350 300 V = 1.5V, MAX870 IN 250 V = 3.3V OR 5.0V, MAX870 IN 200 150 100 -40 - TEMPERATURE (° ...
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... IN than -V , since switches S1–S4 have resistance and the IN load drains charge from C2. Charge-Pump Output The MAX870/MAX871 are not voltage regulators: the charge pump’s output source resistance is approxi- mately 20Ω at room temperature (with V V approaches -5V when lightly loaded. V OUT droop toward GND as load current increases. The ...
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... For applications requiring larger negative voltages, see the MAX864 and MAX865 data sheets. Paralleling multiple MAX870s or MAX871s reduces the output resistance. Each device requires its own pump capacitor (C1), but the reservoir capacitor (C2) serves all devices (Figure 5). Increase C2’ ...
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... MAX870 MAX871 V 1 OUT “n” -nV OUT OUT Figure 5. Paralleling MAX870s or MAX871s to Reduce Output Resistance C1 Figure 6. Combined Doubler and Inverter Figure 7. High V- Load Current … MAX870 MAX870 MAX871 MAX871 1 5 “ ...
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... Switched-Capacitor Voltage Inverters Shutdown Control If shutdown control is necessary, use the circuit in Figure 8. The output resistance of the MAX870/MAX871 will typically be 20Ω plus two times the output resis- tance of the buffer driving IN. The 0.1µF capacitor at the IN pin absorbs the transient input currents of the MAX870/MAX871 ...