LM22670MR-5.0 NSC [National Semiconductor], LM22670MR-5.0 Datasheet
LM22670MR-5.0
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LM22670MR-5.0 Summary of contents
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LM22670 3A SIMPLE SWITCHER®, Step-Down Voltage Regulator with Synchronization or Adjustable Switching Frequency General Description The LM22670 series of regulators are monolithic integrated circuits which provide all of the active functions for a step- down (buck) switching regulator capable of ...
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... Connection Diagrams Ordering Information Output Voltage Order Number ADJ LM22670MR-ADJ ADJ LM22670MRE-ADJ ADJ LM22670MRX-ADJ ADJ LM22670TJE-ADJ ADJ LM22670TJ-ADJ 5.0 LM22670MR-5.0 5.0 LM22670MRE-5.0 5.0 LM22670MRX-5.0 5.0 LM22670TJE-5.0 5.0 LM22670TJ-5.0 www.national.com 30076040 8-Lead Plastic PSOP-8 Package NS Package Number MRA08B 7-Lead Plastic TO-263 THIN Package NS Package Number TJ7A Package Type ...
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Pin Descriptions Pin Numbers Pin Numbers Name PSOP-8 TO-263 THIN Package Package 1 3 BOOT RT/ SYNC GND 7 2 VIN Description Application Information ...
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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 RT/SYNC Pin Voltage SW to GND (Note 2) BOOT Pin Voltage FB Pin ...
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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 www.national.com Normalized Enable Threshold Voltage vs Temperature 30076005 Normalized Feedback Voltage vs Temperature 30076006 Switching Frequency vs RT/SYNC Resistor 30076009 6 30076010 30076007 ...
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Typical Application Circuit and Block Diagram FIGURE 1. 3. 600 kHz OUT 7 30076014 www.national.com ...
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Detailed Operating Description The LM22670 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 is fixed to 500 µs (typical) start-up time and cannot be modified. Switching Frequency Setting and ...
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The typical location of the internal compensation poles and zeros as well as the DC gain is given in Table 1. ...
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L If the switching frequency is set higher than 500 kHz, the ca- pacitance value may not be reduced accordingly due to sta- bility requirements. The internal compensation is optimized for circuits with ...
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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, appropriate guidelines must be followed to reduce the effects of switching noise. Switch mode con- verters ...
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PCB Layout Example for TO-263 THIN Package 13 30076025 www.national.com ...
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PCB Layout Example for PSOP-8 Package www.national.com 14 30076041 ...
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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. 30076026 15 www.national.com ...
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Physical Dimensions www.national.com inches (millimeters) unless otherwise noted 7-Lead Plastic TO-263 THIN Package NS Package Number TJ7A 8-Lead PSOP Package NS Package Number MRA08B 16 ...
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Notes 17 www.national.com ...
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