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Texas Instruments LM2575SX-ADJ/NOPB
- Part No.:
- LM2575SX-ADJ/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
LM2575SX-ADJ/NOPB.pdf
- Description:
- IC REG BUCK ADJ 1A TO263
- Quantity:
- Payment:
- Shipping:
Inventory:1,127
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Product details
Overview
LM2575SX-ADJ/NOPB from Texas Instruments is a monolithic 1A step-down (buck) switching voltage regulator with adjustable output (1.23V to 37V), 52 kHz fixed-frequency internal oscillator, and integrated power switch. It delivers ±4% output voltage accuracy under line/load conditions, supports 40V max input, and requires only four external components for operation - used in industrial power supplies, embedded DC/DC conversion, and pre-regulation stages.
For engineers reviewing the LM2575SX-ADJ/NOPB datasheet, LM2575SX-ADJ/NOPB pinout, LM2575SX-ADJ/NOPB application, or LM2575SX-ADJ/NOPB equivalent, key selection considerations include its TO-263 (DDPAK) package thermal performance (θJA = 37°C/W with 1 in² copper), feedback reference voltage (1.23 V), current limit (1.7–3.2 A peak), and TTL-compatible shutdown capability with 50 μA standby current.
Technical Context
The LM2575SX-ADJ/NOPB implements a fixed-frequency pulse-width modulation (PWM) buck topology with internal 52 kHz oscillator, cycle-by-cycle current limiting, and thermal shutdown protection. Its feedback loop senses voltage at the ADJ pin using a precision 1.23 V reference, enabling output programming via external resistor divider.
It operates across −40°C to +125°C junction temperature, accepts 8–40 V input, and sustains 1 A continuous output current without external heat sink when mounted on ≥1 in² PCB copper area. The device uses a bipolar NPN output switch with 0.9 V typical saturation voltage at 1 A.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 1 A continuous - supports full-load operation without forced air or external heatsink under proper PCB thermal layout. |
| Feedback Voltage | 1.23 V ±2.2% - sets output via R1/R2 divider; enables 1.23–37 V adjustable range with <±4% total output error. |
| Oscillator Frequency | 52 kHz ±10% - fixed internal timing enables predictable EMI profile and simplifies filter design with standard inductors. |
| Input Voltage Range | 8 V to 40 V - compatible with 12 V/24 V industrial rails and battery-backed systems; excludes HV variant. |
| Current Limit | 1.7 A (min) to 3.2 A (max) peak - provides overcurrent protection during startup, short-circuit, or overload without latch-off. |
| Standby Current | 50 μA typical - enables low-power shutdown mode via TTL-level ON/OFF pin; reduces system quiescent draw significantly. |
| Thermal Resistance | 37°C/W (θJA) - achieved with 1 in² copper pour; allows >1 W dissipation at ΔT = 37°C above ambient before thermal shutdown. |
Pinout & Package
LM2575SX-ADJ/NOPB uses a 5-lead DDPAK/TO-263 surface-mount package (package code KTT0005B), with exposed thermal pad soldered to PCB copper for enhanced heat transfer.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - Input | Power input | Accepts 8–40 V DC; requires local 47–100 μF aluminum electrolytic bypass capacitor. |
| 2 - Output | Switched output | Drives external catch diode and LC filter; connects to inductor and output capacitor positive terminal. |
| 3 - Ground | Power and signal reference | Common return for input/output capacitors, feedback network, and thermal pad; must be low-inductance connection. |
| 4 - Feedback (ADJ) | Voltage sense input | Connects to resistor divider midpoint; regulates output by comparing to internal 1.23 V reference. |
| 5 - ON/OFF | Digital enable control | TTL-compatible shutdown pin; <0.8 V disables regulator (50 μA ISTBY); >2.2 V enables operation. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated power switch | Bipolar NPN transistor with 0.9 V saturation voltage at 1 A - eliminates need for external MOSFET driver or gate control circuitry. |
| Fixed-frequency PWM control | 52 kHz oscillator - ensures consistent switching behavior, simplifies EMI filtering, and avoids audible noise in sensitive applications. |
| Internal compensation | Single-pole compensation network - removes requirement for external compensation components; reduces BOM count and layout sensitivity. |
| Protection functions | Thermal shutdown + cycle-by-cycle current limit - prevents damage during sustained overload or ambient temperature rise without external sensing. |
| Standard inductor compatibility | Optimized for off-the-shelf 330–470 μH shielded power inductors - eliminates custom magnetics and accelerates prototyping. |
Applications
| Industrial Power Supply | Embedded System Pre-Regulator |
|---|---|
|
Use Scenario: Converts unregulated 24 V rail to stable 5 V or 12 V for microcontroller, sensor, and interface ICs in factory automation controllers. IC Role / Device Role: Primary non-isolated DC/DC buck converter providing regulated intermediate bus voltage. Use Value: Replaces linear regulators to eliminate >5 W heat dissipation, enabling compact enclosure design without heatsinks. |
Use Scenario: Steps down 12 V battery input to 3.3 V for ARM Cortex-M based edge node in wireless sensor network. IC Role / Device Role: Efficient pre-regulator feeding low-noise LDOs powering analog front-end and RF transceivers. Use Value: Achieves >77% efficiency at 1 A load, extending battery life while maintaining tight output regulation across temperature. |
| On-Card Switching Regulator | Positive-to-Negative Converter |
|
Use Scenario: Integrated 5 V → 3.3 V conversion directly on PCB of medical diagnostic module with space-constrained layout. IC Role / Device Role: Compact, self-contained buck regulator minimizing footprint and component count per voltage domain. Use Value: TO-263 package with thermal pad enables 1 A delivery in <1 cm² area; eliminates need for discrete switcher IC + external FET. |
Use Scenario: Generates −5 V rail from +12 V supply for op-amp biasing in precision instrumentation amplifier stage. IC Role / Device Role: Configured as inverting buck-boost (flyback-like) topology using external inductor and diode. Use Value: Leverages same 52 kHz switching and current limit architecture - no additional controller IC required for dual-rail generation. |
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/NOPB | Higher 3 A current rating, 52 kHz frequency, wider 4–40 V input range, but larger TO-220-5 package and higher quiescent current (10 mA vs 5 mA). | Preferred where >1 A load or higher input transient tolerance is required; less suitable for space-constrained layouts. | Select when output current headroom or input voltage margin exceeds LM2575SX-ADJ/NOPB capability. |
| MP1584EN-LF-Z | 40 V input, 3 A output, 1.5 MHz switching, smaller SOIC-8 package, but requires external compensation and lacks integrated thermal pad. | Better for high-density designs needing faster transient response; not drop-in due to different pinout, control scheme, and layout rules. | Choose for miniaturized applications where board area is critical and design team has experience with high-frequency buck layout. |
Compared with LM2576SX-ADJ/NOPB and MP1584EN-LF-Z, the LM2575SX-ADJ/NOPB offers optimal balance of thermal performance (37°C/W), minimal external component count, and proven reliability in industrial environments - making it ideal for cost-sensitive, thermally demanding, or long-lifecycle applications where 1 A output suffices.
Availability
LM2575SX-ADJ/NOPB 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/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 delivering analog, embedded processing, and connectivity solutions with emphasis on reliability, longevity, and industrial-grade qualification.
The LM2575 series was designed as a robust, easy-to-use replacement for linear regulators in medium-power DC/DC conversion - targeting cost-sensitive industrial, automotive, and telecom applications where thermal simplicity and minimal external parts are critical.
FAQ
What is the maximum input voltage supported by the LM2575SX-ADJ/NOPB?
The LM2575SX-ADJ/NOPB supports a maximum input voltage of 40 V under normal operating conditions. This rating applies specifically to the standard-voltage LM2575 family; the HV variant (LM2575HV) supports up to 60 V. Exceeding 40 V may cause permanent damage or premature failure of the LM2575SX-ADJ/NOPB.
How is the output voltage set for the LM2575SX-ADJ/NOPB?
The LM2575SX-ADJ/NOPB output voltage is set using an external resistor divider connected between output, ADJ pin, and ground. With a precise 1.23 V internal reference at the ADJ pin, the formula VOUT = 1.23 × (1 + R2/R1) determines output. R1 is typically 1–5 kΩ; common values yield outputs like 5 V (R1 = 2.0 kΩ, R2 = 6.12 kΩ) or 12 V (R1 = 2.0 kΩ, R2 = 17.5 kΩ).
Does the LM2575SX-ADJ/NOPB require an external diode, and what type is recommended?
Yes, the LM2575SX-ADJ/NOPB requires an external Schottky catch diode. Recommended types include MBR340 (40 V, 3 A) or SR103 (30 V, 1 A), selected for low forward voltage (<0.5 V) and fast recovery to minimize conduction loss and switching stress. Diode reverse voltage rating must exceed maximum input voltage by ≥25%, and current rating should be ≥1.2× load current.
What thermal performance can be expected from the LM2575SX-ADJ/NOPB in practice?
When mounted on a PCB with ≥1 in² of 2-oz copper connected to its exposed thermal pad, the LM2575SX-ADJ/NOPB achieves θJA = 37°C/W. At 1 A output and 12 V input (≈77% efficiency), power dissipation is ~1.2 W, resulting in ~45°C junction-to-ambient rise - well below the 125°C max junction temperature. No external heatsink is needed under these conditions.
Can the LM2575SX-ADJ/NOPB be used in a negative-output configuration?
Yes, the LM2575SX-ADJ/NOPB can be configured as a positive-to-negative buck-boost converter (inverting topology) by repositioning the inductor and diode. In this mode, it generates a regulated negative output (e.g., −5 V from +12 V) using the same IC, feedback reference, and protection features - though output current capability is reduced by ~20% due to duty-cycle limitations and diode losses.
LM2575SX-ADJ/NOPB 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:
- Active
- 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/NOPB FAQ
1.How can I place an order for LM2575SX-ADJ/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2575SX-ADJ/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 LM2575SX-ADJ/NOPB reliable?
The price and inventory of LM2575SX-ADJ/NOPB 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/NOPB is usually 5 days.
3.What payment methods are accepted for LM2575SX-ADJ/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2575SX-ADJ/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2575SX-ADJ/NOPB?
LM2575SX-ADJ/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2575SX-ADJ/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 LM2575SX-ADJ/NOPB?
For technical support, including LM2575SX-ADJ/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2575SX-ADJ/NOPB requirements.
6.How does Aetrix verify that LM2575SX-ADJ/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2575SX-ADJ/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 LM2575SX-ADJ/NOPB meets industry standards.
7.What is the process for return or replacement of LM2575SX-ADJ/NOPB?
All LM2575SX-ADJ/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2575SX-ADJ/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 LM2575SX-ADJ/NOPB part is unused and in its original packaging.
Return procedure for LM2575SX-ADJ/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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