LM2576S-ADJ/NOPB National Semiconductor, LM2576S-ADJ/NOPB Datasheet - Page 10

• Manufacturer Part Number: LM2576S-ADJ/NOPB
• Description: IC REG SIMPLE SWITCHER TO-263-5
• Manufacturer: National Semiconductor
• Series: SIMPLE SWITCHER®r
• Type: Step-Down (Buck)r

Specifications of LM2576S-ADJ/NOPB

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 1.23 ~ 37 V
• Current - Output: 3A
• Frequency - Switching: 52kHz
• Voltage - Input: 4 ~ 40 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: D²Pak, TO-263 (5 leads + tab)
• Dc To Dc Converter Type: Inverting/Step Down
• Pin Count: 5 +Tab
• Input Voltage: 40V
• Output Voltage: 1.23 to 37V
• Switching Freq: 47 TO 58KHz
• Output Current: 3A
• Efficiency: 77%
• Package Type: TO-263
• Output Type: Adjustable
• Switching Regulator: Yes
• Mounting: Surface Mount
• Input Voltage (min): 4V
• Operating Temp Range: -40C to 125C
• Operating Temperature Classification: Automotive
• Primary Input Voltage: 40V
• No. Of Outputs: 1
• No. Of Pins: 5
• Operating Temperature Range: -40°C To +125°C
• Msl: MSL 3 - 168 Hours
• Filter Terminals: SMD
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Lead Free Status / Rohs Status: Compliant
• Other names: *LM2576S-ADJ; *LM2576S-ADJ/NOPB; LM2576S-ADJ

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Test Circuit and Layout Guidelines
As in any switching regulator, layout is very important. Rap-
idly switching currents associated with wiring inductance
generate voltage transients which can cause problems. For
minimal inductance and ground loops, the length of the leads
indicated by heavy lines should be kept as short as possible.
C
C
D
L
R
R
where V
1
IN
OUT
1
1
2
— 100 µH, Pulse Eng. PE-92108
— Schottky, MBR360
— 2k, 0.1%
— 6.12k, 0.1%
— 100 µF, 75V, Aluminum Electrolytic
— 1000 µF, 25V, Aluminum Electrolytic
REF
= 1.23V, R1 between 1k and 5k.
Adjustable Output Voltage Version
Fixed Output Voltage Versions
FIGURE 2.
10
Single-point grounding (as indicated) or ground plane con-
struction should be used for best results. When using the
Adjustable version, physically locate the programming resis-
tors near the regulator, to keep the sensitive feedback wiring
short.
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