View source for Step-down DC-DC Converter Module

=='''Introduction'''==
The DC-DC module is used to reduce the input voltage and output stable 5 volts voltage. Here the LM2596 switching voltage regulator is used to regulate the voltage.
[[File:Step-module.png]] 
    
The corresponding schematic diagram is as shown in following:
[[File:Dc-dc.png]]
=='''Introduction of LM2596'''==
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The LM2596 regulator is monolithic integrated circuit ideally suited for easy and convenient design of a step−down switching regulator (buck converter). It is capable of driving a 3.0 A load with excellent line and load regulation. It is internally compensated to minimize the number of external components to simplify the power supply design.<br>
Since LM2596 converter is a switch−mode power supply, its efficiency is significantly higher in comparison with popular three−terminal linear regulators, especially with higher input voltages. The LM2596 operates at a switching frequency of 150 kHz thus allowing smaller sized filter components than what would be needed with lower frequency switching regulators. Available in a standard 5−lead TO−220 package with several different lead bend options, and D2PAK surface mount package. <br>
The other features include a guaranteed 4% tolerance on output voltage within specified input voltages and output load conditions, and 15% on the oscillator frequency. External shutdown is included, featuring 80 A (typical) standby current. Self-protection features include switch cycle−by−cycle current limit for the output switch, as well as thermal shutdown for complete protection under fault conditions.
=='''Pin diagram and Function'''==
[[File:Dsadfsa.jpg ]]
Its pin functions are as shown in following:<br>
{| border="1" class="wikitable"
!scope="col" |Pin	
!scope="col" |Name	
!scope="col" |Description
|-
|1	
|VIN	
|This is the positive input supply for the IC switching regulator. A suitable input by pass capacitor must be present at this pin to minimize voltage transients and to supply the switching currents needed by the regulator.
|-
|2	
|GND	
|Circuit ground
|-
|3	
|OUTPUT	
|Internal switch. The voltage at this pin switches between (+V IN − V SAT) and approximately −0.5V, with a duty cycle of approximately V OUT /V IN. To minimize coupling to sensitive circuitry, the PC board copper area connected to this pin should be kept to a minimum
|-
|4	
|Feedback	
|Senses the regulated output voltage to complete the feedback loop
|-
|5	
|ON/OFF	
|Allows the switching regulator circuit to be shut down using logic level signals thus dropping the total input supply current to approximately 80 µA. Pulling this pin below a threshold voltage of approximately 1.3V turns the regulator on, and pulling this pin above 1.3V (up to a maximum of 25V) shuts the regulator down. If this shutdown feature is not needed, the ON /OFF pin can be wired to the ground pin or it can be left open; in either case the regulator will be in the ON condition
|}
=='''Features'''==
Fixed output voltage: 5V<br>
Wide input voltage range, up to 40V<br>
PCB size: 2.5 x 5.0 cm<br>
Guaranteed 3.0 A Output Load Current <br>
150 kHz Fixed Frequency Internal Oscillator<br> 
TTL Shutdown Capability <br>
Low Power Standby Mode, typ 80 μA <br>
Thermal Shutdown and Current Limit Protection<br> 
Internal Loop Compensation <br>
Moisture Sensitivity Level (MSL) Equals 1 <br>
High efficiency<br>
=='''Applications'''==
Simple high-efficiency step-down (buck) regulator<br>
On-card switching regulators<br>
Positive to negative converter<br>
[[File:Power0322.png]]
=='''Resource'''==
[http://www.lengeek.com/wiki/index.php?title=File:LM2596_datasheet.PDF LM2596_datasheet][[File:PDF.jpg]]