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LM2576SX-3.3/NOPB
Texas Instruments
IC REG BUCK 3.3V 3A DDPAK
25262 Pcs New Original In Stock
Buck Switching Regulator IC Positive Fixed 3.3V 1 Output 3A TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
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LM2576SX-3.3/NOPB
Product Overview
1340729
DiGi Electronics Part Number
LM2576SX-3.3/NOPB-DGManufacturer
Texas Instruments
LM2576SX-3.3/NOPB
Description
IC REG BUCK 3.3V 3A DDPAKInventory
25262 Pcs New Original In Stock
Buck Switching Regulator IC Positive Fixed 3.3V 1 Output 3A TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
Quantity
Minimum 1
Minimum 1
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LM2576SX-3.3/NOPB Technical Specifications
Category
Power Management (PMIC), Voltage Regulators - DC DC Switching Regulators
Packaging
Cut Tape (CT) & Digi-Reel®
Series
SIMPLE SWITCHER®
Product Status
Active
Function
Step-Down
Output Configuration
Positive
Topology
Buck
Output Type
Fixed
Number of Outputs
1
Voltage - Input (Min)
4V
Voltage - Input (Max)
40V
Voltage - Output (Min/Fixed)
3.3V
Voltage - Output (Max)
-
Current - Output
3A
Frequency - Switching
52kHz
Synchronous Rectifier
No
Operating Temperature
-40°C ~ 125°C (TJ)
Mounting Type
Surface Mount
Package / Case
TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
Supplier Device Package
TO-263 (DDPAK-5)
Base Product Number
LM2576
Datasheet & Documents
Manufacturer Product Page
LM2576SX-3.3/NOPB Specifications
HTML Datasheet
LM2576SX-3.3/NOPB-DG
Environmental & Export Classification
RoHS Status
ROHS3 Compliant
Moisture Sensitivity Level (MSL)
3 (168 Hours)
REACH Status
REACH Unaffected
ECCN
EAR99
HTSUS
8542.39.0001
Additional Information
Other Names
LM2576SX-3.3-NDR
LM2576SX-3.3/NOPBTR
LM2576SX33NOPB
LM2576SX-3.3/NOPBCT
LM2576SX-3.3/NOPBDKR
2156-LM2576SX-3.3/NOPBTR
*LM2576SX-3.3/NOPB
Standard Package
500
Alternative Parts
PART NUMBER
MANUFACTURER
QUANTITY AVAILABLE
DiGi PART NUMBER
UNIT PRICE
SUBSTITUTE TYPE
Reviews
5.0/5.0-(Show up to 5 Ratings)
de desembre 02, 2025
梱包の質が非常に高く、商品が安全に届きました。
de desembre 02, 2025
The responsiveness and friendliness of the customer support team made my shopping experience excellent.
de desembre 02, 2025
Order processing and shipping happen so swiftly that it enhances our operational efficiency.
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Frequently Asked Questions (FAQ)
What are the key design risks when using the LM2576SX-3.3/NOPB in a high-noise industrial environment, and how can they be mitigated?
When using the LM2576SX-3.3/NOPB in high-noise environments, radiated and conducted EMI from the 52kHz switching frequency can interfere with sensitive analog circuits. Since the LM2576SX-3.3/NOPB lacks synchronous rectification, it exhibits higher switch node ringing and slower diode recovery, increasing EMI risk. To mitigate: use a tightly routed PCB with a solid ground plane, place input capacitors close to the VIN and GND pins, add an RC snubber across the diode, and use a shielded inductor. Consider adding an input LC filter if conducted noise exceeds limits. Ensure the heatsink tab is properly grounded to reduce EMI coupling through stray capacitance.
Can the LM2576SX-3.3/NOPB be used to replace the LM2576-3.3 or NCV4276-3.3 in an existing design, and what compatibility issues should I watch for?
Yes, the LM2576SX-3.3/NOPB can generally replace the LM2576-3.3 as it is the Pb-free, tape-and-reel version with identical electrical specs. However, verify the supplier device package (DDPAK-5) matches your PCB footprint, especially pin spacing and thermal pad alignment. Compared to the NCV4276-3.3 (designed for automotive use), the LM2576SX-3.3/NOPB has lower integration—NCV4276 includes additional protections like current foldback and extended thermal shutdown. If your application demands automotive-grade robustness, consider redesigning with a direct pin-compatible upgrade like the LM2678-3.3 instead.
How do I ensure thermal reliability with the LM2576SX-3.3/NOPB under continuous 3A load at 85°C ambient temperature?
Under continuous 3A load, the LM2576SX-3.3/NOPB can dissipate significant heat due to its non-synchronous design and ~1.5V dropout under high input voltages. At 85°C ambient, ensure the PCB provides at least 3–4 square inches of copper pour connected to the tab for heatsinking. Use multiple thermal vias under the tab to transfer heat to internal or back-side ground planes. Calculate power loss: for example, with 12V input, expect ~2.5W dissipation (considering diode drop and switch losses), leading to >125°C junction temperature without proper cooling. Always derate current as temperature rises and verify with thermal imaging in prototype testing.
What are critical layout mistakes that compromise efficiency when designing in the LM2576SX-3.3/NOPB, and how can they be avoided?
Common layout mistakes with the LM2576SX-3.3/NOPB include long traces between the input capacitor and VIN/GND, which increase parasitic inductance and cause voltage spikes during switching. Also, placing the Schottky diode (required externally) too far from the SW pin increases ringing and EMI. To optimize efficiency: place a low-ESR, high-ripple-current input capacitor (e.g., 100µF electrolytic + 0.1µF ceramic) within 5mm of the input and ground pins. Route the inductor directly from the SW pin to output, minimizing loop area. Avoid splitting the power ground—use a single, solid plane connected to the GND pin and input capacitor ground to prevent noise coupling.
What are the trade-offs of using the LM2576SX-3.3/NOPB versus a modern synchronous buck converter like the LM2678-3.3 or MP1584 in new designs?
The LM2576SX-3.3/NOPB offers simplicity and robustness thanks to its built-in 3A switch and minimal external components, making it suitable for legacy or cost-sensitive designs. However, it is less efficient (typically 75–80%) due to its non-synchronous rectification and 52kHz switching frequency, leading to larger inductors and higher thermal demands. In contrast, modern alternatives like the LM2678-3.3 (switching at 260kHz) or MP1584 (500kHz+) offer synchronous rectification, achieving >90% efficiency and smaller solution size. For new designs prioritizing efficiency, thermal performance, or board space, these newer ICs are preferable—though require more complex feedback tuning and are often more sensitive to PCB layout.
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LM2576SX-3.3/NOPB CAD Models
Texas Instruments LM2576SX-3.3/NOPB PCB symbols & footprints
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