MIC2297 Micrel Semiconductor, MIC2297 Datasheet
MIC2297
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MIC2297 Summary of contents
Page 1
... The MIC2297 is a 600KHz PWM boost-switching regulator that is optimized for driving 6-10 series white LEDs. With its internal 40V switch and a guaranteed switch current of 1.2A, the MIC2297 easily drives a string of 10 white LEDs in series at 20mA, ensuring a high level of brightness and eliminating several ballast resistors. ...
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... Connect the cathode of the LED chain to this pin. Connect current set resistor from this pin to ground. SW Switch Node (Output): Internal power BIPOLAR collector. GND Ground (Return): Backside pad. 2 www.DataSheet4U.com Lead Finish Package ® Pb-Free 10-Pin 2.5 x2.5 MLF ® 10-Pin 2.5 x2.5 MLF Pb-Free FB REF BRT AGND MIC2297 M9999-032708 ...
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... 0V 10V EN IN TURN ON TURN OFF V = 10V BRT BRT BRT V = OPEN BRT MIC2297-42BML (nominal voltage) MIC2297-15BML (nominal voltage) Hysteresis , and the ambient temperature www.DataSheet4U.com (2) ).......................................... 2.5V to 10V IN )....................................40V OUT )..............-40°C to +125°C J ® -10 (θ ).....................................................65°C/W JA Min Typ 2.5 1.8 2 ...
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... INPUT VOLTAGE (V) Efficiency for 10 LEDs @ 20mA vs. Input Voltage 6.8µ INPUT VOLTAGE (V) 4 MIC2297 www.DataSheet4U.com Frequency vs. Input Voltage 800 700 600 500 400 INPUT VOLTAGE (V) LED Current vs. Input Voltage 20 ...
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... LED CURRENT (mA Murata LQH32CN100K11 L1 C1 1µF, 16V VIN EN OVP MIC2297BML REF COMP C3 0.22µF, 10V PWM BRT AGND PGND 5 MIC2297 Efficiency for 9 LEDs vs. LED Current ...
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... Micrel Functional Characteristics Enable Characteristics TIME (2ms/div) Waveform 3. LEDs @ 20mA L = 15µH TIME (1µs/div) Mach 2008 LEDs @ 20mA L = 15µ 0.47µV OUT 0A 6 MIC2297 www.DataSheet4U.com Waveform 3. LEDs @ 5mA L = 15µH 0A TIME (1µs/div) M9999-032708 ...
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... Micrel Block Diagram 1.245V BRT REF 600kHz Oscillator Mach 2008 FB COMP OVP 1.245V + + Ramp Generator MIC2297 Block Diagram 7 MIC2297 www.DataSheet4U.com EN SW PWM Generator GND M9999-032708 ...
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... Micrel Functional Description The MIC2297 is a constant frequency, PWM current mode boost regulator. The MIC2297 uses peak current mode control. The block diagram is shown above. The MIC2297 is composed of an oscillator, slope compensation ramp generator, current amplifier, gm error amplifier, PWM generator, and a 1.2A bipolar output transistor. The oscillator generates a 600kHz clock. The clock’ ...
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... LED is disconnected from the circuit or the feedback pin is shorted to ground, the feedback pin will fall to ground potential. This will cause the MIC2297 to switch at full duty cycle in an attempt to maintain the feedback voltage result, the output voltage will climb out of control. This may ...
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... The input capacitor should be as close as possible to the inductor and the MIC2297, with short traces for good noise performance. The MIC2297 utilizes a feedback pin to compare the LED current to an internal reference. The LED current is adjusted by selecting the appropriate feedback resistor value ...
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... Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully Mach 2008 ® 10-Pin Package MLF indemnify Micrel for any damages resulting from such use or sale. © 2005 Micrel, Incorporated. 11 www.DataSheet4U.com (ML) MIC2297 M9999-032708 ...