LM2576SX-ADJ Detailed explanation of pin function specifications and circuit principle instructions
The LM2576SX-ADJ is a part of the LM2576 family of voltage regulators from Texas Instruments. It is a switching voltage regulator that can step down a higher input voltage to a lower, adjustable output voltage. The "SX-ADJ" version refers to an adjustable version, meaning you can set the output voltage as required with external components.
Pin Function Specifications
The LM2576SX-ADJ has a 5-pin package (TO-263) with the following pinout:
Pin 1 (Ground, GND): This pin is connected to the circuit ground. Pin 2 (Output, Vout): This is the output pin where the regulated voltage is delivered. Pin 3 (Adjust, Adj): This pin is used to set the output voltage. By connecting an external resistor network, you can adjust the output voltage from 1.23V to 37V. Pin 4 (Input, Vin): This is where the unregulated input voltage is supplied. Pin 5 (Switch, SW): This is the switching pin, where the internal switching transistor is connected to an external inductor to generate the correct output voltage.Detailed Pin Function Table
Pin Number Pin Name Pin Function 1 GND Ground pin. Connected to the circuit ground. 2 Vout Output pin. Delivers the regulated output voltage. 3 Adj Adjustment pin. Used to set the output voltage by adjusting the external resistors. 4 Vin Input voltage pin. Provides the unregulated voltage input to the regulator. 5 SW Switch pin. This pin is used to connect the internal switch to an external inductor and generate the correct output voltage.Package Type
The LM2576SX-ADJ is typically found in the TO-263 package, which is a surface-mount device (SMD) package suitable for handling the high currents involved in power conversion. The TO-263 package has 5 leads (pins).
FAQ (Frequently Asked Questions)
What is the LM2576SX-ADJ used for? The LM2576SX-ADJ is used for stepping down an unregulated higher voltage to a lower, adjustable output voltage in power supply designs.
What is the maximum output current for the LM2576SX-ADJ? The maximum output current is 3A, depending on the thermal conditions and external components used.
What is the voltage adjustment range of the LM2576SX-ADJ? The output voltage can be adjusted from 1.23V to 37V.
How do you set the output voltage for the LM2576SX-ADJ? The output voltage is set by an external resistor divider network connected to the "Adjust" pin.
What is the input voltage range for the LM2576SX-ADJ? The input voltage range is from 4V to 40V.
Can the LM2576SX-ADJ be used in a 12V system? Yes, you can use the LM2576SX-ADJ to step down from a higher voltage (e.g., 12V) to a lower, adjustable voltage.
What external components are required to use the LM2576SX-ADJ? You will need an external inductor, diodes, capacitor s, and resistors for voltage adjustment.
What is the recommended inductor value for the LM2576SX-ADJ? The recommended inductor value is typically 330 µH.
Can the LM2576SX-ADJ be used for a 5V output? Yes, by choosing the appropriate resistor values in the external resistor network, the LM2576SX-ADJ can provide a 5V output.
What is the switching frequency of the LM2576SX-ADJ? The switching frequency is typically 52 kHz.
How efficient is the LM2576SX-ADJ? The efficiency can be up to 90%, depending on the input/output voltage ratio and the components used.
Can the LM2576SX-ADJ be used in automotive applications? Yes, it can be used in automotive applications as long as the input voltage range is within specification.
What is the typical application for the LM2576SX-ADJ? It's used in power supply circuits, battery-powered equipment, and low-voltage applications requiring step-down voltage conversion.
Is the LM2576SX-ADJ stable with all load conditions? Yes, it is designed to be stable across a wide range of load conditions.
What is the dropout voltage for the LM2576SX-ADJ? The typical dropout voltage is around 1.2V at 3A output current.
How does the LM2576SX-ADJ protect against short circuits? The LM2576SX-ADJ includes built-in overcurrent and thermal protection to safeguard the circuit in case of short circuits.
What is the operating temperature range of the LM2576SX-ADJ? The operating temperature range is -40°C to +125°C.
Can the LM2576SX-ADJ be used with other voltages besides 12V? Yes, it can step down from any input voltage within its specified range to an adjustable output.
What is the maximum output power for the LM2576SX-ADJ? The maximum output power is typically around 15W, depending on the input/output voltage and current.
How do you select the external resistors for voltage adjustment? The resistor values are selected using the formula provided in the datasheet for the LM2576SX-ADJ. Typically, a resistor divider network is used to set the output voltage.
Conclusion
The LM2576SX-ADJ is a versatile, adjustable voltage regulator with many applications in power supply systems, providing efficient step-down conversion with a wide input voltage range. The detailed pinout and additional component information are crucial for proper circuit design, ensuring that the device operates within its specifications.
