LM22679TJ-ADJ National Semiconductor, LM22679TJ-ADJ Datasheet
LM22679TJ-ADJ
Specifications of LM22679TJ-ADJ
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LM22679TJ-ADJ Summary of contents
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... The current limit threshold can be adjusted using an external resistor. An adjustable soft-start feature is provided by selecting an ap- propriate 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 LM22679TJE-ADJ ADJ LM22679TJ-ADJ 5.0 LM22679TJE-5.0 5.0 LM22679TJ-5.0 Pin Descriptions Pin Name Description 1 SW Switch pin 2 VIN Source input voltage 3 BOOT Bootstrap input 4 GND System ground 5 IADJ Current Limit Setting pin A resistor attached between this pin and GND can be used to set the current limit threshold. ...
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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 SS, IADJ Pin Voltage SW to GND (Note 2) Boot Pin Voltage FB Pin Voltage Power Dissipation Junction Temperature 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 OUT Normalized Switching Frequency vs Temperature Normalized Feedback Voltage vs Temperature www.national.com Unless otherwise specified the following conditions apply: Vin = and V IN 30072327 ...
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Normalized Feedback Voltage vs Input Voltage Current Limit vs IADJ Resistor Soft-start Current vs Temperature 30072309 30072313 5 30072311 www.national.com ...
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Typical Application Circuit and Block Diagram www.national.com FIGURE 1. 3. 4.5A OUT 6 30072314 ...
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Detailed Operating Description The LM22679 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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As a first pass check, if the following equation holds true, a given design is considered in a safe operating area and the current limit will protect the circuit < BLK OUT If ...
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F is the switching frquency which is 500 kHz (typical). This procedure provides a guide to select the value of the inductor L. The nearest standard value will then be used in the circuit. Increasing the inductance will generally ...
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Selecting a total feedback resistance to be below 3 kΩ will provide some minimal load and can keep the output voltage from collapsing in such low load conditions. Catch Diode A Schottky type re-circulating diode is required for all ...
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PCB Layout Example 11 30072325 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 30072326 12 ...
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Physical Dimensions inches (millimeters) unless otherwise noted 7-Lead Plastic TO-263 THIN Package NS Package Number TJ7A 13 www.national.com ...
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