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Texas Instruments LM2576S-12/NOPB
- Part No.:
- LM2576S-12/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
LM2576S-12/NOPB.pdf
- Description:
- IC REG BUCK 12V 3A TO263
- Quantity:
- Payment:
- Shipping:
Inventory:625
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Product details
Overview
LM2576S-12/NOPB from Texas Instruments is a monolithic 3-A non-synchronous step-down (buck) DC-DC regulator in TO-220-5 package, delivering fixed 12 V output with ±4% tolerance over line and load, 52-kHz fixed-frequency operation, and TTL-compatible ON/OFF control. It replaces linear regulators in mid-power industrial supplies, reducing heat sink requirements significantly.
For engineers reviewing the LM2576S-12/NOPB datasheet, LM2576S-12/NOPB pinout, LM2576S-12/NOPB application, or LM2576S-12/NOPB equivalent, key selection criteria include input voltage range (up to 40 V), thermal performance (RθJA = 32.4°C/W), shutdown current (50 µA typ), and compatibility with standard off-the-shelf inductors.
Technical Context
The LM2576S-12/NOPB integrates a 3-A power switch, 52-kHz oscillator, error amplifier, and thermal/current protection circuitry into a single IC. Its fixed 12-V output eliminates external feedback resistors, simplifying design while maintaining ±4% regulation across −40°C to +125°C junction temperature and 15–40 V input range.
It operates in continuous conduction mode under full load and transitions to discontinuous mode at light loads, with cycle-by-cycle current limiting (ICL = 4.2–6.9 A) and automatic frequency foldback (to ~11 kHz) during short-circuit events to limit average power dissipation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 12 V ±4% over full operating temperature and load range - ensures stable rail for microcontrollers and analog circuitry without trimming. |
| Max Input Voltage | 40 V - supports 24-V and 36-V industrial bus inputs with margin for transients. |
| Output Current | 3 A DC - sufficient to power motor drivers, FPGA I/O banks, or multiple peripheral ICs from a single stage. |
| Oscillator Frequency | 52 kHz (±10%) - enables use of low-cost, high-saturation-current toroidal inductors and reduces EMI filtering complexity. |
| Standby Current | 50 µA typical - allows low-power sleep modes in battery-backed or energy-conscious systems. |
| Thermal Resistance | RθJA = 32.4°C/W (TO-220) - enables 3-A operation at ambient up to +75°C with minimal heatsinking. |
| Saturation Voltage | VSAT = 1.4–2.0 V at 3 A - defines minimum dropout (VIN(MIN) ≈ VOUT + VSAT) and conduction loss. |
Pinout & Package
LM2576S-12/NOPB uses the KC (TO-220-5) package with 10.16 mm × 8.51 mm body size and thermally enhanced metal tab connected to GROUND.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VIN | Input supply node | Connects to high-side switch collector; requires low-impedance path to input capacitor to minimize switching noise and voltage spikes. |
| 2 - OUTPUT | Switching node | Drives external inductor and catch diode; high dv/dt node requiring tight layout and ground plane separation. |
| 3 - GROUND | Power and signal reference | Common return for input/output capacitors and feedback network; shortest possible trace to VIN and OUTPUT pins. |
| 4 - FEEDBACK | Regulation sense input | Internally tied to 12-V divider; left unconnected for fixed-output version - no external resistor network needed. |
| 5 - ON/OFF | Enable control input | TTL-compatible: <1.2 V = active, >1.4 V = shutdown; 50-µA standby current when pulled high. |
| TAB | Thermal pad / GND | Electrically and thermally connected to GROUND; must be soldered to large copper area or heatsink for thermal management. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 12-V output | Eliminates external feedback resistors, reducing BOM count and layout sensitivity while guaranteeing ±4% accuracy across temperature and load. |
| 52-kHz fixed-frequency oscillator | Enables predictable EMI spectrum placement and simplifies filter design using standard low-cost inductors rated for ≤100 kHz. |
| TTL shutdown capability | Allows system-level power sequencing and low-quiescent standby (50 µA) without external logic-level translators. |
| Cycle-by-cycle current limiting | Protects internal switch and external components during overload or short-circuit by clamping peak inductor current to 4.2–6.9 A. |
| Thermal shutdown | Disables switching if junction temperature exceeds 150°C, preventing permanent damage during sustained overload or poor heatsinking. |
Applications
| Industrial Motor Drive Power Supply | Embedded Network Equipment PSU |
|---|---|
Use Scenario: Powers gate drivers and logic rails in 24-V brushless DC motor controllers. IC Role / Device Role / Timing Role: Primary 12-V buck regulator supplying isolated gate driver bias and MCU I/O voltage. Use Value: Delivers 3-A continuous current with <2% line regulation, enabling stable gate drive under varying bus conditions. | Use Scenario: Generates 12-V auxiliary rail in merchant Ethernet switches and PoE injectors. IC Role / Device Role / Timing Role: Non-isolated intermediate converter stepping down 48-V backplane to 12-V for fan controllers and PHY interfaces. Use Value: RθJA = 32.4°C/W allows convection-cooled operation at full load in compact chassis designs. |
| Test Equipment Front-End Supply | Home Appliance Control Board |
Use Scenario: Provides clean 12-V rail for op-amp signal conditioning and ADC reference buffers in portable DMMs. IC Role / Device Role / Timing Role: Main DC-DC stage feeding low-noise LDOs; operates in discontinuous mode at standby. Use Value: 52-kHz switching frequency avoids interference with 10–100 kHz measurement bandwidths. | Use Scenario: Supplies 12-V logic and relay coil power in smart washing machine main control boards. IC Role / Device Role / Timing Role: High-reliability primary regulator handling wide-input (18–36 V) battery or rectified AC inputs. Use Value: Withstands 40-V transients per IEC 61000-4-4 and maintains regulation down to 15-V input. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2576HVS-12/NOPB | Higher max input voltage (60 V vs. 40 V); identical pinout, package, and 12-V output spec. | Suitable for 48-V systems with higher transient margins (e.g., automotive 24-V or telecom -48-V derived rails). | Select when input may exceed 40 V; otherwise LM2576S-12/NOPB offers cost and thermal advantage at lower voltage. |
| LMR51430RNXR | Synchronous buck (vs. non-synchronous), 3-A, 4.5–36-V input, 500-kHz/1.1-MHz selectable frequency, smaller 3-mm × 2-mm WSON package. | Requires external compensation and layout optimization for EMI; better efficiency above 12 VIN, but needs more design effort. | Choose for higher efficiency (>90%) and space-constrained designs; LM2576S-12/NOPB remains preferred for simplicity and ruggedness in industrial environments. |
Compared with LM2576HVS-12/NOPB, the LM2576S-12/NOPB trades 20-V input headroom for lower cost and improved thermal resistance in TO-220; versus LMR51430RNXR, it sacrifices efficiency and footprint for plug-and-play reliability with only four external components.
Availability
LM2576S-12/NOPB is available at Aetrix Electronics and suitable for industrial motor drives, embedded network equipment PSUs, test and measurement instruments, and home appliance control boards requiring stable component supply and long-term manufacturability.
Supply support for LM2576S-12/NOPB includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management technologies, with decades of expertise in reliable, high-volume power conversion ICs.
The LM2576 series was designed as a robust, easy-to-use replacement for linear regulators in medium-power industrial and commercial applications, emphasizing fault protection, thermal resilience, and minimal external component count.
FAQ
What is the maximum input voltage rating for LM2576S-12/NOPB?
The absolute maximum input voltage for LM2576S-12/NOPB is 45 V, but the recommended operating maximum is 40 V per TI's datasheet. Exceeding 40 V risks violating safe operating area limits and may trigger thermal shutdown or reduce lifetime reliability. The HV variant (LM2576HVS-12/NOPB) supports up to 60 V input for higher-voltage applications.
Does LM2576S-12/NOPB require an external feedback resistor network?
No. LM2576S-12/NOPB is a fixed-output version with internal 12-V feedback divider. Pin 4 (FEEDBACK) is internally connected and must be left unconnected - no external resistors are needed, unlike the adjustable LM2576ADJ variant which requires two external resistors to set VOUT.
What thermal performance can be expected from LM2576S-12/NOPB in TO-220 package?
In the KC (TO-220-5) package, LM2576S-12/NOPB has RθJA = 32.4°C/W. At 3-A load and 25°C ambient, junction temperature rise is approximately 97°C, resulting in ~122°C TJ - within the 125°C max operating limit only with modest heatsinking. For continuous 3-A operation at elevated ambient, a heatsink or PCB copper pour is required.
How does the ON/OFF pin function on LM2576S-12/NOPB?
The ON/OFF pin (Pin 5) provides TTL-compatible enable control: logic low (<1.2 V) enables regulation; logic high (>1.4 V) places LM2576S-12/NOPB in shutdown with 50 µA typical standby current. It must never be left floating - tie to GND for always-on operation or drive with open-collector/drain logic.
Can LM2576S-12/NOPB be used with standard off-the-shelf inductors?
Yes. LM2576S-12/NOPB is optimized for use with standard 52-kHz-compatible inductors - including shielded drum-core, toroidal, and molded types rated for ≥3.5-A saturation current and ≤0.1 Ω DCR. TI recommends specific part numbers (e.g., Coilcraft MSS1278-153) in application notes, and multiple manufacturers offer drop-in compatible inductors.
LM2576S-12/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Packaging:
- Tube
- 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):
- 12V
- Voltage - Output (Max):
- -
- Current - Output:
- 3A
- Frequency - Switching:
- 52kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-263 (DDPAK-5)
LM2576S-12/NOPB FAQ
1.How can I place an order for LM2576S-12/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2576S-12/NOPB on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LM2576S-12/NOPB reliable?
The price and inventory of LM2576S-12/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2576S-12/NOPB is usually 5 days.
3.What payment methods are accepted for LM2576S-12/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2576S-12/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2576S-12/NOPB?
LM2576S-12/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2576S-12/NOPB order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LM2576S-12/NOPB?
For technical support, including LM2576S-12/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2576S-12/NOPB requirements.
6.How does Aetrix verify that LM2576S-12/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2576S-12/NOPB products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LM2576S-12/NOPB meets industry standards.
7.What is the process for return or replacement of LM2576S-12/NOPB?
All LM2576S-12/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2576S-12/NOPB, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LM2576S-12/NOPB part is unused and in its original packaging.
Return procedure for LM2576S-12/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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