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Texas Instruments LM2575SX-ADJ
- Part No.:
- LM2575SX-ADJ
- Manufacturer:
- Texas Instruments
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
LM2575SX-ADJ.pdf
- Description:
- IC REG BUCK ADJ 1A TO263
- Quantity:
- Payment:
- Shipping:
Inventory:2,397
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Product details
Overview
LM2575SX-ADJ from Texas Instruments is a monolithic 1A step-down (buck) switching voltage regulator with adjustable output (1.23V to 37V), 52 kHz fixed-frequency operation, and integrated switch, thermal shutdown, and current limiting. It replaces linear regulators in industrial power supplies requiring high efficiency and minimal external components.
For engineers reviewing the LM2575SX-ADJ datasheet, LM2575SX-ADJ pinout, LM2575SX-ADJ application, or LM2575SX-ADJ equivalent, key selection criteria include input voltage range (up to 40V), feedback reference voltage (1.23V ±4%), dropout behavior under load, TO-263 package thermal resistance (37°C/W with 1 in² copper), and compatibility with standard off-the-shelf inductors.
Technical Context
The LM2575SX-ADJ implements a fixed-frequency pulse-width modulation (PWM) buck topology with internal 52 kHz oscillator and cycle-by-cycle current limiting. Its feedback loop senses output voltage via an external resistor divider referenced to a precision 1.23V bandgap reference.
Thermal shutdown activates at 150°C junction temperature, and the internal N-channel DMOS switch exhibits 0.9V typical saturation voltage at 1A. Standby mode draws only 50 μA when the ON/OFF pin is pulled high.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 1A continuous - supports medium-power loads without external pass devices |
| Input Voltage Range | 4.75V to 40V - compatible with 5V, 12V, 24V, and 36V input rails |
| Feedback Reference | 1.23V ±4% - sets output via R1/R2 divider; enables precise 1.23–37V adjustment |
| Switching Frequency | 52 kHz ±10% - balances EMI, inductor size, and efficiency for industrial designs |
| Efficiency | 77% at 12VIN/5VOUT/1A - reduces heat sink requirements vs. linear regulators |
| Thermal Resistance | 37°C/W (θJA, DDPAK/TO-263 w/ 1 in² copper) - enables high-power density PCB layout |
| Standby Current | 50 μA typical - supports low-power system sleep modes |
Pinout & Package
LM2575SX-ADJ uses a 5-lead DDPAK/TO-263 surface-mount package (package code KTT0005B), featuring exposed thermal pad for enhanced heat dissipation. The package is RoHS-compliant and designed for reflow soldering.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - Input | Power input | Accepts 4.75–40V DC; requires local 100 μF aluminum electrolytic bypass |
| 2 - Output | Switch node | Drives external catch diode and inductor; high dv/dt node requiring short trace routing |
| 3 - Ground | Power and signal reference | Must connect directly to thermal pad and low-impedance ground plane |
| 4 - Feedback | Regulation sense | Connects to resistor divider midpoint; high-impedance node sensitive to noise |
| 5 - ON/OFF | Enable control | TTL-compatible shutdown; <1.2V disables regulator, >2.2V enables |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 1A DMOS switch | Eliminates need for external MOSFET and gate driver in most 1A buck designs |
| Fixed 52 kHz oscillator | Enables predictable EMI filtering and consistent inductor sizing across designs |
| Internal frequency compensation | Reduces design risk by removing external compensation network tuning |
| Cycle-by-cycle current limit | Protects against short-circuit and overload without latch-up or external sensing |
| Thermal shutdown with hysteresis | Shuts down at 150°C and restarts after cooling ~10°C - prevents thermal runaway |
Applications
| Industrial Power Supply | Embedded System Pre-regulator |
|---|---|
Use Scenario: Provides stable 5V or 12V rail from unregulated 24V factory bus for PLC I/O modules. IC Role / Device Role / Timing Role: Primary buck regulator delivering regulated DC power to downstream logic and analog circuitry. Use Value: Replaces linear regulators to eliminate heat sinks and reduce board area by >40% while maintaining ±4% output accuracy. | Use Scenario: Generates 3.3V intermediate rail from 12V main supply for microcontroller, memory, and peripherals. IC Role / Device Role / Timing Role: Efficient pre-regulator stepping down voltage before low-noise LDOs. Use Value: Achieves 77% efficiency at 1A, cutting power loss by >2W vs. linear solution and enabling compact enclosure design. |
| On-Card DC-DC Conversion | Positive-to-Negative Converter |
Use Scenario: Local 15V generation on motor drive control board from shared 40V DC bus. IC Role / Device Role / Timing Role: Board-level switching regulator eliminating need for external DC-DC module. Use Value: Uses only four external components (inductor, diode, two capacitors) - simplifies BOM and accelerates layout. | Use Scenario: Generates –5V rail from +12V supply for op-amp biasing in instrumentation circuits. IC Role / Device Role / Timing Role: Configured in inverting buck-boost topology using same external parts as buck mode. Use Value: Leverages identical IC and component set for dual-polarity supplies - reduces inventory and qualification effort. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2576SX-ADJ | 57 kHz oscillator, higher peak current limit (3A), wider input range (40V → 60V) | Better suited for higher-input-voltage systems (e.g., automotive 42V or industrial 48V) | Select when input exceeds 40V or higher overload robustness is required |
| MP1584EN-LF-Z | 1.5 MHz switching frequency, smaller external components, no built-in thermal pad | Enables ultra-compact designs but requires careful thermal management on FR-4 | Select for space-constrained consumer or portable applications where PCB area is critical |
Compared with LM2575SX-ADJ, LM2576SX-ADJ offers extended input voltage headroom and higher current fault tolerance, while MP1584EN-LF-Z trades thermal robustness for miniaturization via high-frequency operation - choice depends on priority between thermal reliability, input range, or board area.
Availability
LM2575SX-ADJ is available at Aetrix Electronics and suitable for industrial power supplies, embedded system pre-regulators, and on-card DC-DC conversion requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LM2575SX-ADJ 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 experience in high-reliability power conversion ICs.
The LM2575 series was designed as a drop-in, high-efficiency replacement for three-terminal linear regulators in cost-sensitive industrial and commercial power applications - emphasizing simplicity, thermal resilience, and minimal external component count.
FAQ
What is the maximum input voltage rating for LM2575SX-ADJ?
The absolute maximum input voltage for LM2575SX-ADJ is 45V, but its specified operating range is 4.75V to 40V. Exceeding 40V risks violating the guaranteed performance limits defined in the datasheet, including line regulation, efficiency, and thermal behavior. Always maintain ≥0.5V margin below 45V for reliability, especially under transient conditions.
How do I calculate the output voltage setting resistors for LM2575SX-ADJ?
Use the formula VOUT = 1.23V × (1 + R2/R1), where R1 connects from feedback pin to ground and R2 from output to feedback. Select R1 between 1kΩ and 5kΩ (1% metal film recommended); then solve for R2. For example, for 12V output with R1 = 2.2kΩ, R2 = 2.2kΩ × ((12/1.23) − 1) ≈ 19.3kΩ - use 19.1kΩ (1%). LM2575SX-ADJ relies on this divider for all regulation, so resistor stability directly impacts output accuracy.
Does LM2575SX-ADJ require an external compensation network?
No, LM2575SX-ADJ includes fully internal frequency compensation optimized for standard buck configurations with typical external components (e.g., 330–470 μH inductor, 330 μF output capacitor). Adding external compensation may destabilize the control loop. The IC's fixed 52 kHz oscillator and internal error amplifier are co-designed to ensure stability with the four recommended external parts - no additional capacitors or resistors are needed for basic operation.
What thermal performance can be expected from LM2575SX-ADJ in a real PCB layout?
With 1 in² of 2-oz copper connected to the exposed thermal pad, LM2575SX-ADJ achieves θJA = 37°C/W. At 1A output into 5V with 12V input (77% efficiency), power dissipation is ~1.5W - resulting in ~56°C rise above ambient. This allows reliable operation up to +70°C ambient without forced air. Performance degrades rapidly with less copper: 0.5 in² raises θJA to 50°C/W, increasing junction temperature by ~20°C at same load.
Can LM2575SX-ADJ be used in a buck-boost (inverting) configuration?
Yes, LM2575SX-ADJ supports positive-to-negative conversion using the standard buck-boost topology shown in TI's application notes. Pin 2 (output/switch node) connects to the inductor and diode anode; the output is taken from the diode cathode to ground. The feedback divider references the negative rail. Output magnitude is adjustable from 1.23V to 37V, but polarity is inverted. LM2575SX-ADJ's internal current limit and thermal protection remain fully functional in this mode.
LM2575SX-ADJ 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:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 1.23V
- Voltage - Output (Max):
- 37V
- Current - Output:
- 1A
- 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)
LM2575SX-ADJ FAQ
1.How can I place an order for LM2575SX-ADJ through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2575SX-ADJ 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 LM2575SX-ADJ reliable?
The price and inventory of LM2575SX-ADJ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2575SX-ADJ is usually 5 days.
3.What payment methods are accepted for LM2575SX-ADJ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2575SX-ADJ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2575SX-ADJ?
LM2575SX-ADJ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2575SX-ADJ 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 LM2575SX-ADJ?
For technical support, including LM2575SX-ADJ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2575SX-ADJ requirements.
6.How does Aetrix verify that LM2575SX-ADJ is sourced from the original manufacturer or authorized distributors?
All LM2575SX-ADJ 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 LM2575SX-ADJ meets industry standards.
7.What is the process for return or replacement of LM2575SX-ADJ?
All LM2575SX-ADJ units undergo pre-shipment inspection (PSI). If there is an issue with LM2575SX-ADJ, 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 LM2575SX-ADJ part is unused and in its original packaging.
Return procedure for LM2575SX-ADJ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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