Details

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BUY LM2577T-ADJ. https://www.utsource.net/itm/p/12609457.html

Parameter	Symbol	Conditions	Min	Typ	Max	Unit
Input Voltage	VIN	Operating	4.5	-	40	V
Output Voltage Range	VOUT	Adjustable	1.23	-	37	V
Switching Frequency	fSW	Typical	-	150	-	kHz
Efficiency	η	At 5V in, 5V out, 1A load	-	82	-	%
Quiescent Current	IQ	VIN = 12V, no load	-	5	-	mA
Load Regulation	ΔVOUT	1mA to 1A	-	0.5	-	%
Line Regulation	ΔVOUT	VIN change by ±10%	-	0.05	-	%/V
Dropout Voltage	VDROPOUT	IOUT = 500mA	-	1.2	-	V

Instructions for LM2577T-ADJ:

1. Circuit Configuration:

   • The LM2577T-ADJ is an adjustable version of the LM2577 series step-up voltage regulator.
   • Connect the input voltage (VIN) between the "Vin" and "GND" pins.
   • Connect the output capacitor (COUT) between the "Vout" and "GND" pins.
   • Use a feedback resistor network (R1 and R2) connected from "FB" pin to "Vout" and "GND" to set the desired output voltage.

2. Setting Output Voltage:

   • The output voltage can be adjusted using the formula: [ V_ = 1.23 times left(1 + fracright) ]
   • Choose appropriate values for R1 and R2 to achieve the desired output voltage.

3. Component Selection:

   • Select an inductor with a saturation current higher than the maximum expected output current.
   • Choose capacitors with low ESR for better performance and stability.
   • Ensure that the input and output capacitors have sufficient ripple current ratings.

4. Thermal Considerations:

   • Ensure adequate heat sinking if operating at high output currents or in high ambient temperatures.
   • Monitor the junction temperature to stay within safe operating limits.

5. PCB Layout:

   • Place the input and output capacitors as close as possible to the respective pins.
   • Keep the ground connections short and wide to reduce noise and improve stability.

6. Testing:

   • After assembly, apply the input voltage and measure the output voltage to ensure it matches the desired setting.
   • Test under various load conditions to verify stability and efficiency.

(For reference only)