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onsemi LM2575D2T-3.3
- Part No.:
- LM2575D2T-3.3
- Manufacturer:
- onsemi
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
LM2575D2T-3.3.pdf
- Description:
- IC REG BUCK 3.3V 1A D2PAK-5
- Quantity:
- Payment:
- Shipping:
Inventory:2,977
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Product details
Overview
LM2575D2T-3.3 from onsemi is a monolithic step-down (buck) switching regulator IC delivering 1.0 A output current at a fixed 3.3 V output voltage, with ±4% output voltage tolerance over line and load, 52 kHz internal oscillator frequency, and wide 4.75 V to 40 V input range. It integrates a 1.0 A power switch, thermal shutdown, cycle-by-cycle current limiting, and TTL-compatible ON/OFF control - used in embedded power supplies requiring high efficiency and minimal external components.
For engineers reviewing the LM2575D2T-3.3 datasheet, pinout, applications, or equivalent options, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternative parts with documented differences, and supply-chain support for industrial and automotive-grade deployment.
Technical Context
The LM2575D2T-3.3 implements a voltage-mode controlled buck converter architecture with a fixed 52 kHz oscillator, internal 1.235 V bandgap reference, and error amplifier driving a 1.0 A NPN switch. Its feedback loop uses direct sensing of the regulated 3.3 V output via Pin 4 (Feedback), eliminating external resistor dividers.
It features cycle-by-cycle current limiting (typ. 2.3 A peak), thermal shutdown activation at ~150°C junction temperature, and TTL-level ON/OFF control (VIH ≈ 2.4 V, VIL ≈ 0.8 V) enabling low-power standby mode with 80 µA quiescent current. The device operates across −40°C to +125°C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3 V ±4% over 4.75–40 V input and 0.2–1.0 A load - ensures stable logic rail generation without trimming. |
| Max Output Current | 1.0 A continuous - supports mid-power microcontrollers, FPGAs, and interface ICs without external boost stages. |
| Input Voltage Range | 4.75 V to 40 V - accommodates 5 V, 12 V, 24 V, and 36 V industrial bus inputs with margin for transients. |
| Oscillator Frequency | 52 kHz (±10% over temp) - enables use of low-cost, high-saturation-current off-the-shelf inductors (e.g., 330 µH). |
| Efficiency | 75% at 12 VIN/3.3 VOUT/1.0 A - reduces thermal load vs. linear regulators, often eliminating heatsinks. |
| Standby Quiescent Current | 80 µA typical at 25°C - enables ultra-low-power system sleep modes with ON/OFF pin control. |
| Saturation Voltage | 1.0 V typ. at 1.0 A - defines minimum dropout (VIN ≥ VOUT + 1.0 V) and conduction loss under full load. |
Pinout & Package
D2PAK (TO-263) package (Case 936A), thermally enhanced with heatsink surface electrically connected to Pin 3 (GND). Mounting pad must be soldered to large copper area for thermal management.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - Vin | Positive input supply | Accepts 4.75–40 V unregulated DC; requires local 100 µF low-ESR input capacitor to suppress switching noise. |
| 2 - Output | Emitter of internal NPN switch | Drives inductor; PCB copper area must be minimized to reduce EMI coupling into sensitive analog/feedback paths. |
| 3 - GND | Circuit ground reference | Common return for input cap, output cap, and catch diode; single-point grounding recommended per layout guidelines. |
| 4 - Feedback | Regulated output sense node | Internally tied to 3.3 V output - no external resistors needed; keep trace short and away from noisy nodes. |
| 5 - ON/OFF | Logic-controlled enable/disable | TTL-compatible: ≤0.8 V = ON, ≥2.4 V = OFF; pulls total input current to ~80 µA in shutdown state. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 3.3 V output | Eliminates external feedback resistors - reduces BOM count, layout complexity, and temperature drift errors. |
| Integrated 1.0 A switch | Removes need for external MOSFET and gate driver - simplifies design and improves reliability in space-constrained layouts. |
| Thermal shutdown + current limit | Self-protecting under overload, short-circuit, or inadequate heatsinking - prevents catastrophic failure during field operation. |
| 52 kHz fixed-frequency operation | Enables predictable EMI filtering and compatibility with standard, low-cost power inductors optimized for this frequency. |
| TTL shutdown capability | Allows seamless integration with microcontroller GPIOs for dynamic power sequencing and energy-saving sleep states. |
Applications
| Industrial PLC I/O Module Power | Automotive Body Control Unit (BCU) |
|---|---|
|
Use Scenario: Powers 3.3 V microcontroller, CAN transceiver, and sensor interfaces in DIN-rail mounted PLC modules operating from 24 V DC bus. IC Role / Device Role / Timing Role: Primary non-isolated buck regulator converting 24 V to clean 3.3 V rail; handles load steps up to 1.0 A during digital I/O activation. Use Value: 75% efficiency at full load minimizes heat rise in sealed enclosures; thermal shutdown prevents latch-up during ambient temperature excursions. |
Use Scenario: Supplies 3.3 V domain for infotainment MCU and LIN transceivers in vehicle body electronics exposed to 12 V battery with load dump transients. IC Role / Device Role / Timing Role: Input-stage buck converter accepting 4.75–40 V range - withstands cold-crank (6.5 V) and load-dump (40 V) conditions per ISO 16750. Use Value: Wide VIN range and integrated protection eliminate need for pre-regulator stage, reducing component count and board area. |
| Medical Point-of-Care Diagnostic Device | Smart Energy Meter Power Supply |
|
Use Scenario: Generates isolated 3.3 V logic rail from 5 V USB-derived input in portable diagnostic instruments with strict thermal limits. IC Role / Device Role / Timing Role: High-efficiency local regulator replacing linear LDO - critical for battery runtime extension and passive cooling compliance. Use Value: 80 µA standby current enables >1-year shelf life in shipped devices; ON/OFF pin allows MCU-controlled deep-sleep entry/exit. |
Use Scenario: Provides 3.3 V supply for metrology SoC and RF module in utility-grade smart meters powered by 12 V AC/DC adapter or supercap backup. IC Role / Device Role / Timing Role: Main DC-DC stage supporting continuous operation across -40°C to +85°C ambient with no derating. Use Value: Guaranteed −40°C to +125°C junction operation ensures reliability in outdoor meter enclosures; MSL-1 moisture rating simplifies assembly. |
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-3.3 | TO-220 package (Case 314D); higher RJA (65°C/W vs. 70°C/W); same electrical specs. | Requires mechanical heatsink for >0.7 A continuous loads; less suitable for high-density SMT layouts. | Select when through-hole mounting, manual assembly, or legacy footprint compatibility is required. |
| MP1584EN-LF-Z | 4.5–28 V input; 1.5 A output; adjustable/fixed 3.3 V; 1.5 MHz switching; smaller solution size. | Higher frequency enables smaller inductors/caps but increases EMI sensitivity; not rated for >28 V input. | Select for compact designs where input stays ≤28 V and board space is constrained; verify EMI filtering requirements. |
Compared with LM2575T-3.3, the LM2575D2T-3.3 offers superior thermal performance in SMT form factor, while MP1584EN-LF-Z trades input voltage headroom and EMI robustness for miniaturization - making LM2575D2T-3.3 optimal for industrial 24/36 V systems needing proven ruggedness.
Availability
LM2575D2T-3.3 is available at Aetrix Electronics and suitable for industrial PLCs, automotive body controllers, medical diagnostics, and smart energy meters requiring stable component supply, long lifecycle support, and AEC-Q100-aligned reliability.
Supply support for LM2575D2T-3.3 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
onsemi (formerly ON Semiconductor) is a global semiconductor supplier focused on energy-efficient power management, analog, sensors, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.
The LM2575 series was designed as a cost-optimized, robust buck regulator family for applications demanding high reliability, wide input range, and minimal external components - especially where thermal resilience and long-term availability matter more than ultra-high frequency or digital configurability.
FAQ
What is the maximum input voltage rating for LM2575D2T-3.3?
The absolute maximum input voltage for LM2575D2T-3.3 is 45 V, but the recommended operating maximum is 40 V per the datasheet's Operating Ratings. Exceeding 40 V risks violating guaranteed performance and may trigger internal protection mechanisms. For sustained operation, design with ≤40 V input and include transient suppression if interfacing with automotive or industrial buses subject to load dump.
Does LM2575D2T-3.3 require external feedback resistors?
No, LM2575D2T-3.3 does not require external feedback resistors. As a fixed-output variant, its internal feedback divider is factory-trimmed to regulate precisely at 3.3 V. Pin 4 (Feedback) connects directly to the internal error amplifier reference node and must be left unconnected to external components - unlike the adjustable LM2575-ADJ version.
Can LM2575D2T-3.3 be used in automotive applications?
Yes, LM2575D2T-3.3 is qualified to AEC-Q100 Grade 1 (−40°C to +125°C) and supports automotive use cases such as body control units and infotainment subsystems. Its 4.75–40 V input range covers cold-crank (≥6.5 V) and load-dump (≤40 V) conditions defined in ISO 16750-2, and its thermal shutdown protects against under-hood temperature excursions.
What is the typical efficiency of LM2575D2T-3.3 at full load?
LM2575D2T-3.3 achieves 75% typical efficiency at 12 V input, 3.3 V output, and 1.0 A load. Efficiency rises with higher input-to-output voltage ratios (e.g., 88% at 15 VIN/12 VOUT) and falls at light loads due to fixed quiescent current. Real-world efficiency depends on external component selection - particularly inductor DCR and Schottky diode forward voltage.
How does the ON/OFF pin function on LM2575D2T-3.3?
The ON/OFF pin (Pin 5) enables logic-level shutdown: applying ≤0.8 V (or grounding) turns the regulator ON; applying ≥2.4 V disables switching and reduces total input current to ~80 µA. This pin is TTL-compatible and requires no pull-up; it sources negligible current (<5 µA) in either state, allowing direct connection to MCU GPIOs without level shifting.
LM2575D2T-3.3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4.75V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- 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:
- D2PAK-5
LM2575D2T-3.3 FAQ
1.How can I place an order for LM2575D2T-3.3 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2575D2T-3.3 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 LM2575D2T-3.3 reliable?
The price and inventory of LM2575D2T-3.3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2575D2T-3.3 is usually 5 days.
3.What payment methods are accepted for LM2575D2T-3.3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2575D2T-3.3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2575D2T-3.3?
LM2575D2T-3.3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2575D2T-3.3 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 LM2575D2T-3.3?
For technical support, including LM2575D2T-3.3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2575D2T-3.3 requirements.
6.How does Aetrix verify that LM2575D2T-3.3 is sourced from the original manufacturer or authorized distributors?
All LM2575D2T-3.3 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 LM2575D2T-3.3 meets industry standards.
7.What is the process for return or replacement of LM2575D2T-3.3?
All LM2575D2T-3.3 units undergo pre-shipment inspection (PSI). If there is an issue with LM2575D2T-3.3, 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 LM2575D2T-3.3 part is unused and in its original packaging.
Return procedure for LM2575D2T-3.3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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