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onsemi LM2575D2T-3.3R4
- Part No.:
- LM2575D2T-3.3R4
- Manufacturer:
- onsemi
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
LM2575D2T-3.3R4.pdf
- Description:
- IC REG BUCK 3.3V 1A D2PAK-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,678
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Product details
Overview
LM2575D2T-3.3R4 from onsemi is a monolithic step-down switching regulator (buck converter) delivering 1.0 A output current with fixed 3.3 V output, 52 kHz internal oscillator frequency, and ±4% output voltage tolerance over line and load conditions. It operates across 4.75 V to 40 V input range and integrates thermal shutdown, cycle-by-cycle current limiting, and TTL-compatible ON/OFF control - widely used in industrial power supplies and embedded system pre-regulation.
For engineers reviewing the LM2575D2T-3.3R4 datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed 1.0 A output capability, D2PAK (TO-263) package thermal performance, fixed 3.3 V output without external feedback resistors, and compatibility with standard off-the-shelf 330 µH inductors and Schottky catch diodes.
Technical Context
The LM2575D2T-3.3R4 implements a voltage-mode controlled buck topology with an integrated 1.0 A NPN switch, 1.235 V bandgap reference, and fixed-frequency 52 kHz oscillator. Its error amplifier compares feedback voltage against this reference to drive the PWM comparator and current-limit protection circuitry.
It features internal thermal shutdown triggered at ~150°C junction temperature and cycle-by-cycle peak current limiting set at 1.7–3.0 A (typ. 2.3 A), ensuring robust fault handling. The ON/OFF pin enables logic-level shutdown with 80 µA standby current and 1.4 V typical turn-on threshold.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3 V ±4% over full line/load/temperature range - eliminates need for external feedback divider in 3.3 V systems. |
| Max Output Current | 1.0 A DC - supports mid-power loads such as microcontrollers, FPGAs, and interface ICs without external current boosting. |
| Input Voltage Range | 4.75 V to 40 V - accommodates wide-range unregulated inputs including 12 V, 24 V, and 36 V industrial rails. |
| Oscillator Frequency | 52 kHz (±10%) - enables use of low-cost, high-saturation-current inductors and reduces EMI filtering complexity vs. MHz-range converters. |
| Efficiency | 75% at 12 VIN/1.0 AOUT - significantly higher than linear regulators under same conditions, minimizing heatsink requirements. |
| Standby Current | 80 µA typical at ON/OFF = 5 V - enables ultra-low-power shutdown mode for battery-backed or energy-sensitive applications. |
| Saturation Voltage | 1.0 V typ. at 1.0 A - defines minimum dropout (VIN − VOUT) required for regulation; impacts thermal design at high IOUT. |
Pinout & Package
D2PAK-5 (TO-263-5) package with exposed thermal pad connected to Pin 3 (GND); heatsink surface must be soldered to PCB copper area for thermal management. Pin 1 (Vin) and Pin 2 (Output) carry high-switching-current paths; Pin 4 (Feedback) is sensitive analog node requiring short trace routing.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - Vin | Positive input supply | Accepts 4.75–40 V unregulated DC; requires low-ESR input capacitor (e.g., 100 µF/50 V) placed adjacent to pin to suppress switching transients. |
| 2 - Output | Emiter of internal NPN switch | Delivers regulated 3.3 V; saturation voltage ≤1.2 V at 1.0 A determines conduction loss and thermal rise; PCB copper area must be minimized to reduce noise coupling. |
| 3 - GND | Circuit ground reference | Common return for input/output capacitors, inductor, and catch diode; single-point grounding recommended to avoid ground loops and EMI. |
| 4 - Feedback | Regulated output sensing node | Internally connected to 3.3 V output via precision resistor divider; no external components needed for fixed-output version; sensitive to noise - route away from switching nodes. |
| 5 - ON/OFF | Logic-controlled enable/disable | TTL-compatible input: <1.4 V = ON, >2.2 V = OFF; draws only 15–30 µA when high; allows system-level power sequencing and sleep-mode control. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 3.3 V output | Eliminates external feedback resistors and associated layout sensitivity - simplifies BOM and improves production yield for 3.3 V rail generation. |
| Integrated thermal shutdown | Automatically disables switching at ~150°C junction temperature and recovers after cooldown - prevents permanent damage during overload or poor heatsinking. |
| Cycle-by-cycle current limit | Clamps peak switch current to ~2.3 A (typ.), limiting inductor stress and enabling reliable operation into short-circuit or heavy transient loads. |
| 52 kHz fixed-frequency operation | Enables predictable EMI spectrum and compatibility with low-cost, high-current inductors optimized for 50–100 kHz - avoids ferrite core saturation issues seen at lower frequencies. |
| TTL shutdown capability | Supports direct interfacing with microcontroller GPIOs or logic supervisors without level-shifting - enables precise power-state control in embedded systems. |
Applications
| Industrial PLC Power Supply | Embedded Microcontroller Pre-regulator |
|---|---|
|
Use Scenario: Providing stable 3.3 V rail from noisy 24 V DC field bus in programmable logic controller backplanes. IC Role / Device Role / Timing Role: Primary step-down regulator converting unregulated 24 V to clean 3.3 V for ARM Cortex-M4 MCU and peripheral ICs. Use Value: High efficiency (≥75% at 1 A) minimizes heat buildup in sealed enclosures; 40 V max input withstands load-dump transients per ISO 7637-2. |
Use Scenario: Generating 3.3 V from 12 V automotive battery supply for infotainment SoC subsystems. IC Role / Device Role / Timing Role: Buck converter supplying core logic voltage with ON/OFF pin synchronized to vehicle ignition state. Use Value: 80 µA standby current extends battery life in accessory-off mode; thermal shutdown protects against under-hood temperature excursions. |
| IoT Sensor Node Power Management | POS Terminal Main Rail Converter |
|
Use Scenario: Powering low-power wireless sensor modules (BLE/Wi-Fi) operating from 9–36 V solar or battery sources. IC Role / Device Role / Timing Role: Efficient DC-DC stage stepping down variable input to fixed 3.3 V for RF transceivers and ADCs. Use Value: Wide 4.75–40 V input range accommodates fluctuating solar panel output; D2PAK package enables compact heatsinking on small PCBs. |
Use Scenario: Delivering 1.0 A @ 3.3 V to payment processing module in retail point-of-sale terminals. IC Role / Device Role / Timing Role: Primary power converter feeding FPGA, display driver, and secure element ICs from 12 V main rail. Use Value: Guaranteed 1.0 A output ensures headroom for burst current demands during card swipe or NFC activation; ±4% output tolerance meets IPC-9592 Class 2 requirements. |
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-220-5 package; higher RJA (65°C/W vs. 70°C/W); identical electrical specs and pinout. | Requires larger heatsink or forced air for 1.0 A continuous operation at elevated ambient temperatures. | Select when mechanical mounting constraints favor TO-220 or legacy board compatibility is required. |
| MP1584EN-LF-Z | 4.5–28 V input; 1.5 A output; 1.4 MHz switching; requires external feedback resistors for 3.3 V. | Better suited for space-constrained designs needing higher efficiency at light loads; not drop-in due to different pinout and control architecture. | Choose for new designs prioritizing size reduction and light-load efficiency, accepting redesign effort for feedback network and layout. |
Compared with LM2575T-3.3, the LM2575D2T-3.3R4 offers superior thermal resistance in surface-mount form factor, while MP1584EN-LF-Z trades simplicity and ruggedness for higher frequency and density - making LM2575D2T-3.3R4 optimal for cost-sensitive, thermally demanding industrial applications where proven reliability outweighs miniaturization goals.
Availability
LM2575D2T-3.3R4 is available at Aetrix Electronics and suitable for industrial PLC power supplies, embedded microcontroller pre-regulators, IoT sensor node power management, and POS terminal main rail conversion requiring stable component supply and long-term manufacturability.
Supply support for LM2575D2T-3.3R4 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 is a global semiconductor supplier focused on energy-efficient innovation for automotive, industrial, cloud, and IoT applications, with leadership in power management and signal processing.
The LM2575 series was designed for simple, robust, and cost-effective non-isolated DC-DC conversion in industrial and automotive environments - emphasizing ease of design, thermal resilience, and long-lifecycle support over feature density.
FAQ
What is the maximum input voltage rating for LM2575D2T-3.3R4?
The absolute maximum input voltage for LM2575D2T-3.3R4 is 45 V, but the recommended operating maximum is 40 V per the datasheet's Operating Ratings. Exceeding 40 V risks violating safe operating area limits, especially under high ambient temperature or full load, and may trigger thermal shutdown or reduce long-term reliability. Always maintain ≥0.5 V margin below 45 V in final design validation.
Does LM2575D2T-3.3R4 require external feedback resistors to set its output voltage?
No, LM2575D2T-3.3R4 does not require external feedback resistors because it is the fixed 3.3 V output variant. The feedback divider is fully integrated internally, connecting Pin 4 directly to the regulated 3.3 V output. This eliminates resistor tolerance errors, layout sensitivity, and BOM cost - distinguishing it from the adjustable LM2575ADJ version which requires external R1/R2.
What inductor value is recommended for LM2575D2T-3.3R4 in a standard 12 V input, 1.0 A application?
For LM2575D2T-3.3R4 operating from 12 V input at 1.0 A output, the datasheet specifies a 330 µH inductor (e.g., part code L330) as optimal. This value balances ripple current, transient response, and core saturation margin. Recommended parts include Pulse PE-52627 or Renco RL1952 - both rated for ≥1.5 A DC and 52 kHz operation with low DCR to minimize conduction loss.
How does the ON/OFF pin function on LM2575D2T-3.3R4, and what logic levels activate it?
The ON/OFF pin (Pin 5) of LM2575D2T-3.3R4 enables TTL-compatible shutdown: applying <1.4 V (typically 0 V) turns the regulator ON; applying >2.2 V (up to VIN) forces it into low-quiescent standby mode drawing only ~80 µA. The pin has low input current (<30 µA), allowing direct connection to microcontroller GPIOs without buffering - critical for power sequencing in battery-powered systems.
Is LM2575D2T-3.3R4 RoHS-compliant and halogen-free?
Yes, LM2575D2T-3.3R4 is a Pb-free device compliant with RoHS Directive 2011/65/EU and halogen-free per JEDEC JS709B. The "R4" suffix in the part number explicitly denotes RoHS-compliant packaging and material content, verified in onsemi's official product change notices and material declarations - essential for compliance in EU, China, and other regulated markets.
LM2575D2T-3.3R4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- 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):
- 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-3.3R4 FAQ
1.How can I place an order for LM2575D2T-3.3R4 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2575D2T-3.3R4 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-3.3R4 reliable?
The price and inventory of LM2575D2T-3.3R4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2575D2T-3.3R4 is usually 5 days.
3.What payment methods are accepted for LM2575D2T-3.3R4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2575D2T-3.3R4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2575D2T-3.3R4?
LM2575D2T-3.3R4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2575D2T-3.3R4 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-3.3R4?
For technical support, including LM2575D2T-3.3R4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2575D2T-3.3R4 requirements.
6.How does Aetrix verify that LM2575D2T-3.3R4 is sourced from the original manufacturer or authorized distributors?
All LM2575D2T-3.3R4 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-3.3R4 meets industry standards.
7.What is the process for return or replacement of LM2575D2T-3.3R4?
All LM2575D2T-3.3R4 units undergo pre-shipment inspection (PSI). If there is an issue with LM2575D2T-3.3R4, 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-3.3R4 part is unused and in its original packaging.
Return procedure for LM2575D2T-3.3R4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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