Details

---

BUY LM2574M-ADJ/NOPB https://www.utsource.net/itm/p/12541681.html

Parameter	Symbol	Min	Typical	Max	Unit
Input Voltage	VIN	4.5	-	40	V
Output Voltage (Adjustable)	VOUT	1.23	-	37	V
Output Current	IOUT	-	3	3	A
Switching Frequency	fSW	-	52	52	kHz
Efficiency	η	-	84	90	%
Dropout Voltage	VDROPOUT	-	1.2	1.5	V
Load Regulation	-	-	0.1	0.5	%
Line Regulation	-	-	0.01	0.1	%/V
Ripple Rejection	-	-	60	70	dB
Operating Temperature	Toper	-40	-	125	°C
Storage Temperature	Tstg	-65	-	150	°C
Package Type	-	-	TO-220	-	-

Instructions for Using the LM2574M-ADJ/NOPB

1. Input Capacitor (CIN):

   • Place a 10 μF to 100 μF electrolytic capacitor between the input voltage and ground to filter out high-frequency noise.

2. Output Capacitor (COUT):

   • Use a 100 μF to 1000 μF electrolytic capacitor between the output and ground to smooth the output voltage.
   • For better transient response, add a 0.1 μF ceramic capacitor in parallel with the electrolytic capacitor.

3. Feedback Resistor Network:

   • The output voltage is set using a resistor divider network connected to the ADJ pin.
   • Calculate the resistors using the formula: ( V_ = 1.23 left(1 + fracright) ).
   • Typical values for R1 and R2 are 1 kΩ and 4.7 kΩ, respectively, for a 5 V output.

4. Inductor Selection:

   • Choose an inductor with a value between 100 μH and 1000 μH.
   • Ensure the inductor can handle the maximum current without saturating.

5. Diode Selection:

   • Use a Schottky diode to minimize forward voltage drop and improve efficiency.
   • The diode should be rated for at least 1.2 times the maximum output current and have a reverse voltage rating higher than the input voltage.

6. Thermal Considerations:

   • Ensure adequate heat sinking for the TO-220 package, especially when operating at high currents or high ambient temperatures.
   • The junction-to-case thermal resistance is typically 1.5 °C/W.

7. Layout Guidelines:

   • Keep the input and output capacitors as close as possible to the IC.
   • Use wide traces for power and ground connections to reduce resistance and inductance.
   • Avoid long traces between the inductor and the IC to minimize parasitic inductance.

8. Stability:

   • The LM2574M-ADJ/NOPB is internally compensated and stable over a wide range of load and line conditions.
   • However, ensure that the output capacitor has an ESR (Equivalent Series Resistance) between 0.3 Ω and 3 Ω for optimal stability.

By following these guidelines, you can ensure reliable and efficient operation of the LM2574M-ADJ/NOPB in your application.

(For reference only)