Details

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BUY LM2575T-ADJ https://www.utsource.net/itm/p/12510453.html

Parameter	Symbol	Min	Typ	Max	Unit	Notes
Input Voltage	VIN	4.5	-	40	V
Output Voltage (Adjustable)	VOUT	1.23	-	37	V	Set by external resistor divider
Output Current	IOUT	-	3	5	A	Maximum output current depends on input voltage and thermal conditions
Switching Frequency	fSW	52	-	100	kHz	Fixed frequency operation
Efficiency	η	-	84	-	%	Typical efficiency at 5V in, 5V out, 1A load
Dropout Voltage	VDROPOUT	-	1.5	-	V	At full load
Load Regulation	ΔVOUT/ΔILOAD	-	0.01	-	%/A	Change in output voltage with respect to load current
Line Regulation	ΔVOUT/ΔVIN	-	0.001	-	%/V	Change in output voltage with respect to input voltage
Ripple Rejection	RR	-	60	-	dB	At 100 Hz
Start-Up Time	tSTART	-	200	-	μs	Time from VIN applied to VOUT reaching regulation
Thermal Shutdown	TSD	-	160	-	°C	Device turns off if junction temperature exceeds this value
Storage Temperature Range	TSTG	-40	-	125	°C	Temperature range for storage and non-operating conditions

Instructions for Using the LM2575T-ADJ

1. Input Capacitor (CIN):

   • Use a 0.33 μF or larger ceramic or tantalum capacitor to filter the input voltage.
   • Place the capacitor close to the input pin to minimize noise and improve stability.

2. Output Capacitor (COUT):

   • Use a 100 μF or larger electrolytic capacitor to smooth the output voltage.
   • For better transient response, add a 0.1 μF ceramic capacitor in parallel with COUT.

3. Feedback Resistor Divider:

   • The output voltage is set using a resistor divider connected between the output (VOUT), the feedback (FB) pin, and ground.
   • The formula to calculate the resistors is: ( V_ = 1.23 left(1 + fracright) ).
   • Choose R1 and R2 such that the total resistance is between 1 kΩ and 100 kΩ to ensure proper operation.

4. Inductor Selection:

   • Select an inductor with a saturation current rating higher than the maximum expected output current.
   • A typical value is 100 μH for most applications.
   • Ensure the inductor has low DC resistance to minimize power loss.

5. Thermal Considerations:

   • Ensure adequate heat sinking for high current applications to keep the junction temperature below the thermal shutdown threshold.
   • Use a heatsink or a PCB with a large copper area to dissipate heat.

6. PCB Layout:

   • Keep the traces short and wide to reduce parasitic inductance and resistance.
   • Place the input and output capacitors as close as possible to the respective pins.
   • Ensure good grounding practices to minimize noise and improve stability.

7. Protection Circuits:

   • The LM2575T-ADJ includes built-in overcurrent and thermal protection.
   • No additional protection circuits are typically required unless specific application requirements dictate otherwise.

By following these guidelines, you can effectively design and implement a power supply using the LM2575T-ADJ regulator.

(For reference only)