Details

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BUY LM2598S-3.3 https://www.utsource.net/itm/p/12532875.html

Below is the parameter table and instructions for the LM2598S-3.3 DC-DC Step-Down Voltage Regulator.

LM2598S-3.3 Parameter Table

Parameter	Symbol	Min	Typ	Max	Unit	Conditions
Input Voltage	( V_ )	4.5	-	40	V
Output Voltage	( V_ )	3.3	3.3	3.3	V	Fixed output voltage
Output Current	( I_ )	-	3	3	A
Quiescent Current	( I_Q )	-	5	10	mA	No load, typical at 25掳C
Shutdown Current	( I_ )	-	0.01	0.02	渭A	Shutdown mode
Switching Frequency	( f_ )	150	150	150	kHz	Fixed frequency
Efficiency	( eta )	-	90	-	%	Typical at full load, 12V to 3.3V
Operating Temperature	( T_ )	-40	-	125	掳C	Junction temperature range
Storage Temperature	( T_ )	-65	-	150	掳C
Thermal Resistance	( R_{theta JA} )	-	50	-	掳C/W	Junction-to-air (TO-220 package)

Instructions for Using LM2598S-3.3

1. Circuit Configuration:

   • Input Capacitor (( C_ )): Use a 10渭F tantalum or ceramic capacitor to filter the input voltage.
   • Output Capacitor (( C_ )): Use a 100渭F electrolytic or tantalum capacitor to smooth the output voltage.
   • Inductor (( L )): Use a 100渭H inductor to store energy during the switching cycle.
   • Feedback Resistor (( R_F )): Not required as the output voltage is fixed at 3.3V.
   • Shutdown Pin (( SHDN )): Connect to ground to enable the regulator. Leave open or connect to Vcc to disable the regulator.

2. Layout Considerations:

   • Place the input and output capacitors as close as possible to the IC to minimize noise and improve stability.
   • Ensure that the inductor has a saturation current rating higher than the maximum output current.
   • Use wide traces for power paths to reduce resistance and heat generation.

3. Thermal Management:

   • The TO-220 package can dissipate heat through the metal tab. Mount the IC on a heatsink if operating at high temperatures or under high load conditions.
   • Ensure adequate ventilation to prevent overheating.

4. Protection:

   • The LM2598S-3.3 includes overcurrent protection and thermal shutdown to protect against short circuits and excessive temperature.
   • Add a fuse on the input side to protect against input overvoltage or reverse polarity.

5. Testing:

   • Measure the output voltage with a multimeter to ensure it is stable at 3.3V.
   • Check the ripple on the output voltage using an oscilloscope to ensure it is within acceptable limits (typically less than 50mV peak-to-peak).

By following these instructions, you can effectively use the LM2598S-3.3 in your DC-DC conversion applications.

(For reference only)