LM22680MRX-ADJ/NOPB National Semiconductor, LM22680MRX-ADJ/NOPB Datasheet
LM22680MRX-ADJ/NOPB
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LM22680MRX-ADJ/NOPB Summary of contents
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... An adjustable soft-start feature is provided by selecting an appropriate external soft-start capacitor. Simplified Application Schematic © 2011 National Semiconductor Corporation LM22680/LM22680Q Features ■ Wide input voltage range: 4.5V to 42V ■ ...
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... Output Order Number Voltage ADJ LM22680MR-ADJ ADJ LM22680MRE-ADJ ADJ LM22680MRX-ADJ ADJ LM22680QMR-ADJ ADJ LM22680QMRE-ADJ ADJ LM22680QMRX-ADJ *Automotive Grade (Q) product incorporates enhanced manufacturing and support processes for the automotive market, including defect detection methodologies. Reliability qualification is compliant with the requirements and temperature grades defined in the AEC-Q100 standard. Automotive grade products are identified with the letter Q ...
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... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. VIN to GND EN Pin Voltage SS, RT/SYNC Pin Voltage SW to GND (Note 2) BOOT Pin Voltage FB Pin Voltage Power Dissipation Electrical Characteristics junction temperature (T ) range of -40° ...
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Typical Performance Characteristics 12V 25°C. J Efficiency vs I OUT V = 3.3V 500 kHz OUT O Current Limit vs Temperature Feedback Bias Current vs Temperature www.national.com Unless otherwise specified the following conditions apply: Vin = ...
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Standby Quiescent Current vs Input Voltage Normalized Feedback Voltage vs Input Voltage Soft-start Current vs Temperature Normalized Feedback Voltage vs Temperature 30080706 Switching Frequency vs RT/SYNC Resistor 30080709 30080742 5 30080707 30080713 www.national.com ...
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Typical Application Circuit and Block Diagram www.national.com FIGURE 1. 3. 600 kHz OUT 6 30080714 ...
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Detailed Operating Description The LM22680 switching regulator features all of the functions necessary to implement an efficient high voltage buck regu- lator using a minimum of external components. This easy to use regulator integrates a 42V N-Channel switch with an ...
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FIGURE 2. Output Current in Foldback vs. Nominal Duty Cycle The percentage of output current limit fold back is affected by duty cycle, inductance, and See Figure 2 for details. The current limit will only protect the inductor from a ...
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FIGURE 3. Switching Frequency vs RT/SYNC Resistor Self Synchronize It is also possible to self-synchronize multiple LM22680 reg- ulators to share the same switching frequency. This can be done by attaching the RT/SYNC pins together and putting a 1 kΩ ...
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Inductor The inductor value is determined based on the load current, ripple current, and the minimum and maximum input voltage. To keep the application in continuous current conduction mode (CCM), the maximum ripple current, I less than twice the minimum ...
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FIGURE 5. Resistive Feedback Divider A maximum value of 10 kΩ is recommended for the sum of R1 and R2 to keep high output voltage accuracy. At loads less than 5 mA, the boot capacitor will not hold enough ...
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The junction-to-ambient thermal resistance of the LM22680 will vary with the application. The most signifi- cant variables are the area of copper in the PC board, the number of ...
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PCB Layout Example 13 30080741 www.national.com ...
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Schematic for Buck/Boost (Inverting) Application See AN-1888 for more information on the inverting (buck- boost) application generating a negative output voltage from a positive input voltage. www.national.com 14 30080726 ...
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Physical Dimensions inches (millimeters) unless otherwise noted 8-Lead Plastic PSOP-8 Package NS Package Number MRA08B 15 www.national.com ...
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