LM22679TJE-ADJ/NOPB National Semiconductor, LM22679TJE-ADJ/NOPB Datasheet
LM22679TJE-ADJ/NOPB
Specifications of LM22679TJE-ADJ/NOPB
Related parts for LM22679TJE-ADJ/NOPB
LM22679TJE-ADJ/NOPB 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 © 2010 National Semiconductor Corporation LM22679 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 Electrical Characteristics junction temperature (T ) range of -40°C to +125°C. Minimum and Maximum limits are guaranteed through test, design, or statistical J correlation ...
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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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FIGURE 3. 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 3 for details. The current limit will only protect the inductor from a ...
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The peak ramp level of the oscillator signal feeding into the PWM comparator is V /10 which equals a gain of 20dB of IN this modulator stage of the IC. The -5.0 fixed output voltage option has twice the gain ...
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For the -ADJ option no resistor divider is required for 1.285V output voltage. The output voltage should be directly con- nected to the FB pin. Other output voltages can use the -ADJ option with a resistor divider. The resistor values ...
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FIGURE 5. Current Flow in a Buck Application Thermal Considerations The two highest power dissipating components are the re- circulating diode and the LM22679 regulator IC. The easiest method to determine the power dissipation within the LM22679 is to measure ...
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PCB Layout Example www.national.com 12 30072325 ...
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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. 13 30072326 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 14 ...
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Notes 15 www.national.com ...
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