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Texas Instruments LM2575T-ADJ/LF03
- Part No.:
- LM2575T-ADJ/LF03
- Manufacturer:
- Texas Instruments
- Package:
- TO-220-5 Formed Leads
- Datasheet:
-
LM2575T-ADJ/LF03.pdf
- Description:
- IC REG BUCK ADJ 1A TO220-5
- Quantity:
- Payment:
- Shipping:
Inventory:340
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Product details
Overview
LM2575T-ADJ/LF03 from Texas Instruments is a monolithic 1A step-down (buck) switching voltage regulator in TO-220 package, featuring adjustable output (1.23V–37V), 52 kHz fixed-frequency operation, and ±4% output voltage tolerance under line/load conditions. It replaces linear regulators in medium-power DC/DC conversion, reducing heat sink requirements in industrial power supplies.
For engineers reviewing the LM2575T-ADJ/LF03 datasheet, LM2575T-ADJ/LF03 pinout, LM2575T-ADJ/LF03 application, or LM2575T-ADJ/LF03 equivalent, key selection criteria include input voltage range (up to 40V), thermal shutdown protection, TTL-compatible shutdown pin, feedback bias current (50 nA typ), and compatibility with standard off-the-shelf inductors.
Technical Context
The LM2575T-ADJ/LF03 integrates a PWM controller, power switch, oscillator, error amplifier, and thermal/current protection circuitry in a single TO-220 package. Its internal 52 kHz oscillator enables stable operation with minimal external components-only four required: input capacitor, output capacitor, catch diode, and inductor.
Feedback is taken from the ADJ pin referencing an internal 1.23V bandgap reference; output voltage is set by external resistive divider (R1/R2). Cycle-by-cycle current limiting (2.2 A peak) and thermal shutdown ensure fault robustness without external sensing circuitry.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 1 A continuous load capability - supports medium-power rails without external pass devices |
| Input Voltage Range | 4.75 V to 40 V - compatible with 5 V, 12 V, 24 V, and 36 V industrial bus systems |
| Output Voltage Range | 1.23 V to 37 V (adjustable) - configured via external resistor divider; 1.23 V reference tolerance ±2.5% |
| Switching Frequency | 52 kHz (fixed) - enables use of low-cost, high-saturation-current inductors; reduces EMI filtering complexity |
| Efficiency | 77% at 12 VIN/5 VOUT, 1 A - significantly higher than linear regulators, minimizing thermal design burden |
| Quiescent Current | 5 mA operating / 50 μA standby - enables low-power modes via TTL-compatible ON/OFF pin |
| Thermal Protection | Internal thermal shutdown at ~150 °C junction - prevents damage during overload or poor heatsinking |
Pinout & Package
LM2575T-ADJ/LF03 uses a 5-lead TO-220 package (package code NDH0005D), with tab electrically connected to Pin 2 (Output). Mounting requires thermal interface to heatsink for >0.5 A continuous loads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - Input | Unregulated DC input supply | Accepts 4.75–40 V; requires local 100 μF/75 V electrolytic bypass |
| 2 - Output | Regulated switched output node | Connected to inductor and catch diode anode; tab is electrically tied to this pin |
| 3 - Ground | Power and signal reference | Single-point ground connection critical for noise immunity and stability |
| 4 - Feedback | Resistive divider sense input | References internal 1.23 V bandgap; sets output via R1–R2 divider (R1 = 1–5 kΩ) |
| 5 - ON/OFF | TTL-compatible enable control | Logic high (>2.2 V) enables regulation; logic low (<0.8 V) disables output and reduces IQ to 50 μA |
Key Features
| Feature | Design Value |
|---|---|
| Integrated power switch | Internal NPN transistor with 0.9 V saturation voltage at 1 A - eliminates external MOSFET driver and gate drive complexity |
| Fixed-frequency oscillator | 52 kHz ±10% - ensures predictable EMI profile and simplifies filter design vs. variable-frequency alternatives |
| Current limit protection | 2.2 A peak cycle-by-cycle limiting - prevents inductor saturation and component overstress during short-circuit events |
| Thermal shutdown | Auto-recovery after junction cools below ~140 °C - maintains system integrity without latch-up or manual reset |
| Low-feedback bias current | 50 nA typical - minimizes divider resistor power loss and improves accuracy with high-value resistors (e.g., 100 kΩ+) |
Applications
| Industrial Power Supply | Embedded System Pre-regulator |
|---|---|
Use Scenario: 24 V rail conversion to 5 V/1 A for PLC I/O modules with ambient temperatures up to 70 °C. IC Role / Device Role / Timing Role: Primary buck regulator providing isolated, efficient, and thermally robust DC/DC conversion. Use Value: Eliminates need for large heatsinks; 77% efficiency at full load reduces board-level thermal management complexity. |
Use Scenario: Pre-regulation stage feeding a low-noise LDO in a sensor node powered from a 12 V battery pack. IC Role / Device Role / Timing Role: High-efficiency intermediate converter stepping 12 V down to 3.3 V before final LDO filtering. Use Value: Reduces LDO power dissipation by >60% versus direct 12 V → 3.3 V linear regulation, extending battery life. |
| On-Card DC/DC Converter | Positive-to-Negative Inverter |
Use Scenario: Local 15 V generation on a motor control board from a shared 36 V supply, requiring compact layout and minimal BOM count. IC Role / Device Role / Timing Role: Standalone buck regulator using only four external components - inductor, diode, and two capacitors. Use Value: Achieves <15 mm × 15 mm footprint with no custom magnetics; leverages widely available 330 μH inductors (e.g., PE-52627). |
Use Scenario: Generating –5 V from +12 V for op-amp biasing in analog front-end circuits. IC Role / Device Role / Timing Role: Buck-boost topology implementation using LM2575T-ADJ/LF03 in inverting configuration per Figure 25. Use Value: Enables bipolar supply generation without dedicated inverting ICs; maintains 52 kHz switching for consistent filter design. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2575T-5.0/LF03 | Fixed 5 V output; no external feedback resistors required; same TO-220 package and pinout | Eliminates R1/R2 design effort but lacks output flexibility; unsuitable for non-5 V rails | Select when 5 V is the sole required output and BOM simplification is prioritized over adjustability |
| LM2596T-ADJ | Higher 3 A output current; 150 kHz switching frequency; improved efficiency (≥85% at 12 VIN/5 VOUT) | Requires smaller inductor/capacitor; better suited for higher-power or space-constrained designs | Choose for >1 A loads or where higher efficiency and smaller passive components justify redesign |
Compared with LM2575T-5.0/LF03, the LM2575T-ADJ/LF03 trades fixed-output simplicity for programmable voltage capability; compared with LM2596T-ADJ, it offers proven legacy reliability and lower EMI due to 52 kHz operation, at the cost of reduced current and efficiency.
Availability
LM2575T-ADJ/LF03 is available at Aetrix Electronics and suitable for industrial power supplies, embedded pre-regulators, on-card DC/DC converters, and positive-to-negative inverter circuits requiring stable component supply across extended temperature and long-lifecycle programs.
Supply support for LM2575T-ADJ/LF03 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 ICs, with decades of expertise in switching regulator design and manufacturing.
The LM2575 series was engineered as a drop-in replacement for linear regulators in medium-power applications, targeting cost-sensitive industrial, automotive, and consumer systems needing high efficiency and minimal external components.
FAQ
What is the maximum input voltage rating for the LM2575T-ADJ/LF03?
The LM2575T-ADJ/LF03 has an absolute maximum input voltage of 45 V and an operating maximum of 40 V. Exceeding 40 V risks violating specified performance limits, while operation above 45 V may cause permanent damage. The HV variant (LM2575HVT-ADJ) supports up to 60 V input for higher-voltage applications.
How is the output voltage set on the LM2575T-ADJ/LF03?
The LM2575T-ADJ/LF03 uses an internal 1.23 V reference connected to the Feedback (Pin 4) terminal. Output voltage is set by a resistive divider: VOUT = 1.23 V × (1 + R2/R1), where R1 connects from ADJ to GND and R2 from VOUT to ADJ. R1 should be 1–5 kΩ for optimal stability and temperature coefficient.
Does the LM2575T-ADJ/LF03 require a heatsink under full-load conditions?
Yes - at 1 A output with high input-to-output differential (e.g., 40 VIN/5 VOUT), power dissipation exceeds 35 W, necessitating a heatsink. With the TO-220 package's θJA = 65 °C/W (no heatsink), junction temperature would exceed 150 °C. A heatsink reducing θJA to ≤30 °C/W is recommended for continuous 1 A operation.
Can the LM2575T-ADJ/LF03 be used in a buck-boost (inverting) configuration?
Yes - the LM2575T-ADJ/LF03 supports inverting configurations per TI's Application Note SLVA001. In this mode, the output generates a negative voltage referenced to input ground (e.g., –5 V from +12 V), using the same external components as the buck circuit but with modified inductor/diode placement and grounding.
What is the purpose of the ON/OFF pin (Pin 5) on the LM2575T-ADJ/LF03?
Pin 5 provides TTL-compatible enable/disable control: applying ≥2.2 V enables regulation; ≤0.8 V disables the internal switch and reduces quiescent current to 50 μA typical. This allows system-level power sequencing and low-power sleep modes without removing input voltage.
LM2575T-ADJ/LF03 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- TO-220-5 Formed Leads
- Packaging:
- Bulk
- 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:
- Through Hole
- Supplier Device Package:
- TO-220-5
LM2575T-ADJ/LF03 FAQ
1.How can I place an order for LM2575T-ADJ/LF03 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2575T-ADJ/LF03 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 LM2575T-ADJ/LF03 reliable?
The price and inventory of LM2575T-ADJ/LF03 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2575T-ADJ/LF03 is usually 5 days.
3.What payment methods are accepted for LM2575T-ADJ/LF03?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2575T-ADJ/LF03 transactions.
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4.How is shipping managed for LM2575T-ADJ/LF03?
LM2575T-ADJ/LF03 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2575T-ADJ/LF03 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 LM2575T-ADJ/LF03?
For technical support, including LM2575T-ADJ/LF03 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2575T-ADJ/LF03 requirements.
6.How does Aetrix verify that LM2575T-ADJ/LF03 is sourced from the original manufacturer or authorized distributors?
All LM2575T-ADJ/LF03 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 LM2575T-ADJ/LF03 meets industry standards.
7.What is the process for return or replacement of LM2575T-ADJ/LF03?
All LM2575T-ADJ/LF03 units undergo pre-shipment inspection (PSI). If there is an issue with LM2575T-ADJ/LF03, 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 LM2575T-ADJ/LF03 part is unused and in its original packaging.
Return procedure for LM2575T-ADJ/LF03:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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