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Texas Instruments LM2576SX-15
- Part No.:
- LM2576SX-15
- Manufacturer:
- Texas Instruments
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
LM2576SX-15.pdf
- Description:
- IC REG BUCK 15V 3A TO263
- Quantity:
- Payment:
- Shipping:
Inventory:2,683
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Product details
Overview
LM2576SX-15 from Texas Instruments is a monolithic 3-A non-synchronous step-down (buck) DC-DC regulator in TO-220-5 (KC) package, delivering fixed 15-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 and embedded power supplies where thermal efficiency and minimal external components are critical.
For engineers reviewing the LM2576SX-15 datasheet, LM2576SX-15 pinout, LM2576SX-15 application, or LM2576SX-15 equivalent, key selection factors include its 40-V max input voltage, 3-A continuous output current capability, cycle-by-cycle current limiting, thermal shutdown protection, and compatibility with standard off-the-shelf inductors - all verified for stable operation across −40°C to +125°C junction temperature.
Technical Context
The LM2576SX-15 integrates a high-side NPN switch, fixed-frequency oscillator (47–58 kHz), error amplifier with 1.23-V internal reference, and comparator-based PWM control. Its non-synchronous architecture uses an external catch diode, enabling efficient conversion from 18 V to 40 V input down to regulated 15 V at up to 3 A.
Functional modes include active regulation (ON/OFF pin <1.2 V), shutdown (<50 μA standby current when ON/OFF >1.4 V), and fault protection via cycle-by-cycle current limit (4.2–6.9 A typical) and thermal shutdown. Output voltage accuracy is maintained by feedback sensing directly at the output capacitor for fixed versions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 15 V ±4% over full line/load/temperature range - ensures stable rail for logic, analog, or motor drive circuitry without external resistive divider. |
| Max Input Voltage | 40 V - supports wide-input industrial supplies, battery systems up to 36 V nominal, and transient-tolerant designs. |
| Output Current | 3 A continuous - sufficient for powering multiple ICs, small motors, or sensor subsystems without parallel devices. |
| Oscillator Frequency | 52 kHz (typical), 42–63 kHz over temperature - enables use of low-cost, high-saturation-current inductors and reduces EMI filtering complexity. |
| Efficiency | 88% at VIN = 18 V, IOUT = 3 A - minimizes heat generation and eliminates need for heatsink in many PCB layouts. |
| Standby Current | 50 μA typical at shutdown - supports low-power sleep modes in battery-backed or energy-conscious systems. |
| Saturation Voltage | 1.8 V max at 3 A - defines minimum dropout (VIN ≥ VOUT + VSAT ≈ 16.8 V), setting practical lower input limit for regulation. |
| Current Limit | 4.2–6.9 A - provides robust overload protection while allowing safe startup into capacitive loads. |
Pinout & Package
LM2576SX-15 is housed in a 5-pin TO-220 (KC) package with exposed tab thermally connected to GND. The tab must be mounted to a heatsink or large copper pour for thermal management per RθJA = 32.4°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VIN | Power input | Connects to high-side transistor collector; requires short-path, low-ESR input capacitor (≥100 μF) near pin to suppress switching noise. |
| 2 - OUTPUT | Switching node | Emitter of internal NPN switch; connects to inductor and cathode of external catch diode - high dv/dt node requiring careful layout. |
| 3 - GROUND | Power return | Common reference for internal circuits and external components; shortest possible path to CIN and heatsink tab is mandatory. |
| 4 - FEEDBACK | Voltage sense | Internally tied to output for fixed 15-V version; left unconnected externally - not used in this variant. |
| 5 - ON/OFF | Enable control | TTL-compatible digital input: <1.2 V = ON, >1.4 V = OFF; 50 μA standby current allows direct MCU GPIO control. |
| TAB | Thermal & electrical ground | Internally connected to GND; must be soldered to PCB copper plane or heatsink for thermal relief and EMI reduction. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 15-V output | Eliminates external resistor divider, reducing BOM count and improving long-term stability versus adjustable variants. |
| Integrated cycle-by-cycle current limiting | Prevents destructive overcurrent during short-circuit or heavy-load transients without external sensing components. |
| TTL shutdown with 50-μA standby | Enables precise system-level power sequencing and ultra-low quiescent power in sleep states. |
| Thermal shutdown protection | Automatically disables switching if junction temperature exceeds 150°C, preventing permanent damage under sustained overload. |
| Requires only four external components | Input cap, output cap, inductor, and catch diode - simplifies design, accelerates prototyping, and improves reliability vs. discrete solutions. |
| Optimized for standard inductors | Supports widely available off-the-shelf 150-μH shielded inductors rated for ≥3.5 A DC, lowering sourcing risk and cost. |
Applications
| Industrial Motor Drives | Network Equipment Power |
|---|---|
Use Scenario: Powering gate drivers and logic for 24-V DC brushless motor controllers in factory automation. IC Role / Device Role / Timing Role: Primary 15-V intermediate rail generator converting 36-V bus to clean, regulated supply for MOSFET drivers and microcontrollers. Use Value: Delivers 3-A peak current with 88% efficiency, reducing thermal load on compact enclosures and eliminating need for forced air cooling. | Use Scenario: Generating 15-V auxiliary rail in merchant-class Ethernet switches and PoE injectors. IC Role / Device Role / Timing Role: Secondary buck converter downstream of main AC/DC front-end, supplying PHYs, fans, and management controllers. Use Value: Fixed 15-V output ensures consistent timing margin for 10/100/1000BASE-T PHYs; 52-kHz frequency avoids interference with Ethernet signaling bands. |
| Test Equipment Power Supply | Home Appliance Control Board |
Use Scenario: Providing stable 15-V bias for op-amps, DACs, and relays in portable multimeters and signal generators. IC Role / Device Role / Timing Role: Precision analog supply regulator with low output ripple (<100 mVpp typical) and excellent line regulation (±0.2%). Use Value: ±4% output tolerance and 1.8-V saturation voltage ensure accurate voltage references even under varying input conditions. | Use Scenario: Powering MCU, display backlight, and solenoid drivers in washing machine and dishwasher main control boards. IC Role / Device Role / Timing Role: Main 15-V system rail sourced from 48-V battery or rectified AC, supporting both digital and electromechanical loads. Use Value: Built-in thermal shutdown and current limiting protect against fault conditions during pump stall or heater element failure. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2576T-15 | Same electrical specs and pinout; TO-220-5 package with different mechanical marking (T vs SX suffix), identical thermal performance. | No functional difference; used interchangeably in legacy designs and distributor stock. | Select LM2576T-15 if sourcing from distributors listing T-suffix inventory; no redesign or layout change required. |
| LM2576HV-15 | Higher 60-V max input voltage (vs 40 V); otherwise identical 15-V output, 3-A rating, and pinout. | Required for 48-V battery systems, 36-V+ industrial buses, or applications with high-voltage transients exceeding 40 V. | Choose LM2576HV-15 only when input may exceed 40 V; otherwise LM2576SX-15 offers optimal cost/performance balance. |
Compared with LM2576T-15, LM2576SX-15 is functionally identical but reflects updated TI manufacturing traceability; compared with LM2576HV-15, it trades 20-V input headroom for tighter thermal resistance and lower unit cost in 40-V-limited systems.
Availability
LM2576SX-15 is available at Aetrix Electronics and suitable for industrial motor drives, network equipment power supplies, and appliance control boards requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for LM2576SX-15 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 designing analog, embedded processing, and connectivity technologies for industrial, automotive, and consumer markets.
The LM2576 series was engineered as a SIMPLE SWITCHER® solution to replace inefficient linear regulators in cost-sensitive, thermally constrained 3-A power applications - emphasizing ease of use, minimal external parts, and robust fault protection.
FAQ
What is the maximum input voltage rating for LM2576SX-15?
The LM2576SX-15 has a maximum continuous input voltage rating of 40 V, with absolute maximum rating of 45 V. Operation above 40 V risks permanent damage and violates recommended operating conditions. For 48-V or higher input systems, the LM2576HV-15 variant (60-V max) must be used instead of LM2576SX-15.
Does LM2576SX-15 require an external feedback resistor network?
No, LM2576SX-15 does not require external feedback resistors. As a fixed-output 15-V variant, its internal feedback divider is factory-trimmed and connected internally; the FEEDBACK pin (Pin 4) is unused and left unconnected in standard operation. This simplifies design and improves output voltage stability versus adjustable versions.
Can LM2576SX-15 be used without a heatsink?
LM2576SX-15 can operate without an external heatsink at light loads (<1 A) and ambient temperatures ≤40°C, thanks to its 32.4°C/W junction-to-ambient thermal resistance in TO-220 package. At full 3-A load with 18-V input, thermal calculations show ~30°C rise - acceptable for short durations. For continuous 3-A operation, mounting the tab to ≥1 in² copper area or a heatsink is strongly recommended to maintain TJ <125°C.
What type of catch diode is recommended for LM2576SX-15?
A Schottky diode rated for ≥3.5 A average current and ≥60 V PIV is recommended for LM2576SX-15, such as the 1N5822 or SB560. Schottky diodes minimize forward voltage drop (typically 0.4–0.5 V), reducing conduction losses and improving efficiency. Fast-recovery PN diodes may be used but reduce efficiency by ~3–5% due to higher VF and reverse recovery losses.
Is LM2576SX-15 compatible with LM2576-15 variants from other manufacturers?
LM2576SX-15 is a Texas Instruments part number and is not guaranteed compatible with second-source or clone versions labeled LM2576-15. While pinout and basic functionality may match, TI's LM2576SX-15 includes proprietary process optimizations, tighter parameter tolerances (e.g., ±4% VOUT), and validated thermal performance. For reliable operation, use only TI-manufactured LM2576SX-15 or authorized equivalents with documented cross-reference data.
LM2576SX-15 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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):
- 15V
- 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)
LM2576SX-15 FAQ
1.How can I place an order for LM2576SX-15 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2576SX-15 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 LM2576SX-15 reliable?
The price and inventory of LM2576SX-15 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2576SX-15 is usually 5 days.
3.What payment methods are accepted for LM2576SX-15?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2576SX-15 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2576SX-15?
LM2576SX-15 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2576SX-15 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 LM2576SX-15?
For technical support, including LM2576SX-15 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2576SX-15 requirements.
6.How does Aetrix verify that LM2576SX-15 is sourced from the original manufacturer or authorized distributors?
All LM2576SX-15 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 LM2576SX-15 meets industry standards.
7.What is the process for return or replacement of LM2576SX-15?
All LM2576SX-15 units undergo pre-shipment inspection (PSI). If there is an issue with LM2576SX-15, 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 LM2576SX-15 part is unused and in its original packaging.
Return procedure for LM2576SX-15:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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