lm22671mrx-adj National Semiconductor Corporation, lm22671mrx-adj Datasheet
lm22671mrx-adj
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lm22671mrx-adj 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 © 2008 National Semiconductor Corporation Features ■ Wide input voltage range: 4.5V to 42V ■ ...
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... Connection Diagram Ordering Information Output Voltage Order Number ADJ LM22671MR-ADJ ADJ LM22671MRE-ADJ ADJ LM22671MRX-ADJ 5.0 LM22671MR-5.0 5.0 LM22671MRE-5.0 5.0 LM22671MRX-5.0 Pin Descriptions Pin Name Description 1 BOOT Bootstrap input 2 SS Soft-start pin 3 RT/SYNC Oscillator frequency adjust pin or frequency synchronization 4 FB Feedback pin 5 EN Precision enable pin ...
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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 ...
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Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur, including inoperability and degradation of device reliability and/or performance. Functional operation of the device and/or non-degradation at the Absolute Maximum Ratings or other conditions beyond ...
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Feedback Bias Current vs Temperature Standby Quiescent Current vs Input Voltage Normalized Feedback Voltage vs Input Voltage Normalized Enable Threshold Voltage vs Temperature 30076805 Normalized Feedback Voltage vs Temperature 30076806 Switching Frequency vs RT/SYNC Resistor 30076809 5 30076810 30076807 30076813 ...
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Soft-start Current vs Temperature www.national.com 30076842 6 ...
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Typical Application Circuit and Block Diagram FIGURE 1. 3. 500 mA at 600 kHz OUT 7 30076814 www.national.com ...
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Detailed Operating Description The LM22671 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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Soft-Start The soft-start feature allows the regulator to gradually reach the initial steady state operating point, thus reducing start-up stresses and surges. The soft-start can be adjusted by se- lecting an external soft-start capacitor. An internal 50 µA current source ...
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Thermal Protection Internal Thermal Shutdown circuitry protects the LM22671 in the event the maximum junction temperature is exceeded. When activated, typically at 150°C, the regulator is forced into a low power reset state. There is a typical hysteresis of 15 ...
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Quality ceramic capacitors with a low ESR should be selected for the input filter. To allow for capacitor tolerances and volt- age effects, multiple capacitors may be used in parallel. If step input voltage transients are expected near the maximum ...
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Circuit Board Layout Board layout is critical for switching power supplies. First, the ground plane area must be sufficient for thermal dissipation purposes. Second, ...
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PCB Layout Example 13 30076841 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 30076826 14 ...
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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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... National Semiconductor and the National Semiconductor logo are registered trademarks of National Semiconductor Corporation. All other brand or product names may be trademarks or registered trademarks of their respective holders. ...