AAT3122_05 ANALOGICTECH [Advanced Analogic Technologies], AAT3122_05 Datasheet
AAT3122_05
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AAT3122_05 Summary of contents
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General Description The AAT3122 is a low noise, constant frequency charge pump DC/DC converter that uses a dual mode load switch (1X) and fractional (1.5X) con- version to increase efficiency in white LED applica- tions. With input voltages ranging from ...
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Pin Descriptions Pin # Symbol Function 1 C2+ Flying capacitor 2 positive terminal. Connect a 1µF capacitor between C2+ and C2-. 2 OUT Charge pump output. Requires 1µF bypass capacitor to ground. 3 C1- Flying capacitor 1 negative terminal. 4 ...
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Absolute Maximum Ratings Symbol Description V Input Voltage IN V Charge Pump Output OUT V EN/SET to GND Voltage EN/SET V Maximum EN/SET to Input Voltage EN/SET(MAX Maximum DC Output Current OUT T Operating Junction Temperature Range J ...
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Electrical Characteristics V = 3.5V OUT 25°C. A Symbol Description Input Power Supply V Operation Range IN I Operating Current cc I Shutdown Current SHDN I Maximum Output ...
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Typical Characteristics Unless otherwise noted 3.6V Efficiency vs 80mA) D 100 3.3V 90 DIODE 3.4V DIODE DIODE 65 V DIODE ...
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Typical Characteristics Unless otherwise noted 3.6V Turn-On to Full-Scale Charge Pump ENSET (1V/div) OUT (2V/div) V DIODE (1V/div (200mA/div) Time (50µs/div) Charge Pump to Load Switch (80mA (10mV/div) OUT (2V/div) V DIODE ...
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Functional Block Diagram EN/SET Functional Description The AAT3122 is a dual mode load switch (1X) and high efficiency (1.5X) fractional charge pump device intended for white LED backlight applications. The fractional charge pump consists of a low dropout lin- ear ...
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Applications Information Current Level Settings LED current level is set via the serial interface according to a logarithmic scale, where each code is 1dB greater than the previous code. In this man- ner, the LED brightness appears linear with each ...
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EN/SET Timing Diagram EN/SET Code OFF LED Selection The AAT3122 is specifically intended for driving white LEDs. However, the device design will allow the AAT3122 to drive most types of LEDs with forward voltage specifications ranging from 2.0V to 4.3V. ...
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Capacitor Selection Careful selection of the four external capacitors and C is important because they will OUT affect turn-on time, output ripple, and transient per- formance. Optimum performance will be obtained ...
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Additional Application Circuit BATTERY 1µF 1µF EN/SET *In some applications, white LED forward voltages (V recommended for balancing the forward voltage differences. The ballast resistor value may be approxiamted by the following equation Maximum ...
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Ordering Information Package TSOPJW-12 All AnalogicTech products are offered in Pb-free packaging. The term “Pb-free” means semiconductor products that are in compliance with current RoHS standards, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. For ...