My Inquiry
My Account
onsemi LM2576T-3.3G
- Part No.:
- LM2576T-3.3G
- Manufacturer:
- onsemi
- Package:
- TO-220-5
- Datasheet:
-
LM2576T-3.3G.pdf
- Description:
- IC REG BUCK 3.3V 3A TO220-5
- Quantity:
- Payment:
- Shipping:
Inventory:142
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM2576T-3.3G from onsemi is a monolithic 3.0 A, 52 kHz fixed-frequency step-down (buck) switching regulator with fixed 3.3 V output, designed for high-efficiency DC-DC conversion in industrial and embedded power supplies. It operates from 7.0 V to 40 V input, delivers ±4% output voltage tolerance over line/load/temperature, and integrates thermal shutdown, cycle-by-cycle current limiting, and TTL-compatible ON/OFF control.
For engineers reviewing the LM2576T-3.3G 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-ready availability details - all grounded in the official onsemi LM2576/D Rev. 11 datasheet.
Technical Context
The LM2576T-3.3G implements a voltage-mode controlled buck topology with an internal 52 kHz oscillator, 1.235 V bandgap reference, and integrated 3.0 A NPN switch. Its feedback loop uses a precision error amplifier comparing output voltage (via internal resistive divider for fixed versions) against the reference to adjust duty cycle.
Protection features include cycle-by-cycle peak current limiting (typ. 5.8 A at 25 °C), thermal shutdown at 150 °C junction temperature, and automatic frequency foldback to ~18 kHz under overload/short-circuit conditions - reducing average power dissipation by lowering minimum duty cycle to ~2%.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3 V ±4% over −40 °C to +125 °C, 6.0–40 V input, 0.5–3.0 A load - ensures stable logic rail generation without external feedback components. |
| Max Output Current | 3.0 A continuous - supports mid-power microcontroller, FPGA I/O, or sensor subsystems without external current boosting. |
| Input Voltage Range | 7.0 V to 40 V - accommodates 12 V/24 V industrial buses and unregulated AC-DC outputs with margin for ripple and transients. |
| Switching Frequency | 52 kHz (±10% over temp) - enables use of low-cost, standard off-the-shelf inductors (e.g., 100 µH Pulse PE-92108) and simplifies EMI filtering vs. MHz-range converters. |
| Efficiency | 75% typical at 12 VIN/3.0 AOUT - reduces thermal load vs. linear regulators; often eliminates need for heatsink in moderate ambient conditions. |
| Standby Current | 80 µA typical at 25 °C when ON/OFF pin = 5 V - enables ultra-low-power system sleep modes without external disconnect circuitry. |
| Thermal Resistance | RθJC = 5.0 °C/W (TO-220 case 314D) - allows direct heatsink mounting to Pin 3 (GND) for reliable 3 A operation up to +125 °C ambient with proper thermal design. |
Pinout & Package
LM2576T-3.3G is housed in a TO-220 package (Case 314D), with Pin 3 (GND) electrically connected to the metal heatsink tab for low-impedance thermal and ground path. The package is Pb-free and moisture sensitivity level (MSL) 1 - suitable for standard reflow and manual assembly without baking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - Vin | Positive input supply | Accepts 7–40 V unregulated DC; requires local 100 µF low-ESR electrolytic bypass capacitor to suppress switching transients and supply peak inductor current. |
| 2 - Output | Emiter of internal NPN switch | Drives inductor; saturation voltage ≤1.8 V at 3 A - contributes directly to conduction loss and must be routed with minimal PCB area to reduce EMI coupling. |
| 3 - GND | Circuit ground reference | Common return for input/output capacitors, catch diode, and feedback network; also heatsink connection - must be single-point grounded near IC for stability. |
| 4 - Feedback | Regulated output sensing node | Internally connected to fixed 3.3 V divider; not user-accessible - eliminates external resistor selection but prevents output adjustment. |
| 5 - ON/OFF | TTL-compatible enable/disable control | Logic-high ≥2.2 V (25 °C) disables regulator, dropping quiescent current to 80 µA; open or logic-low ≤1.2 V enables operation - supports microcontroller-controlled power sequencing. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed-output architecture | Eliminates external feedback resistors - reduces BOM count, layout complexity, and temperature drift vs. adjustable variants. |
| Integrated protection suite | Combines thermal shutdown, cycle-by-cycle current limit, and frequency foldback - enables robust operation under short-circuit, overload, and overtemperature without external supervision. |
| Standard inductor compatibility | Optimized for widely available 100 µH pulse inductors (e.g., Pulse PE-92108) - accelerates design cycle and avoids custom magnetics procurement. |
| Low standby current | 80 µA typical enables battery-backed or energy-harvesting systems to maintain >1-year shelf life without significant drain during sleep. |
| Pb-free TO-220 package | Meets RoHS requirements and supports standard lead-free reflow profiles - simplifies compliance for global industrial and automotive-adjacent designs. |
Applications
| Industrial PLC I/O Power | Embedded Microcontroller Core Supply |
|---|---|
Use Scenario: Providing clean, regulated 3.3 V power to digital I/O modules in programmable logic controllers operating from 24 V DC field buses. IC Role / Device Role / Timing Role: Primary step-down regulator converting 24 V bus to isolated 3.3 V logic rail; handles load steps up to 3 A during module activation. Use Value: High efficiency (≥75%) minimizes heat buildup in sealed enclosures; built-in current limiting protects against field-wiring faults without fuse replacement. |
Use Scenario: Powering ARM Cortex-M or RISC-V microcontrollers and associated peripherals (SPI flash, sensors, UART transceivers) in edge-node IoT gateways. IC Role / Device Role / Timing Role: Main system regulator delivering stable 3.3 V at up to 3 A; supports dynamic voltage scaling and deep-sleep wake-up via ON/OFF pin. Use Value: 80 µA standby current extends battery life in solar-powered deployments; fixed 3.3 V output ensures direct compatibility with 3.3 V logic families without calibration. |
| On-Card DC-DC Conversion | Pre-Regulator for Linear LDOs |
Use Scenario: Generating local 3.3 V rails on dense PCBs where space constraints preclude multi-stage buck-boost solutions. IC Role / Device Role / Timing Role: Compact, self-contained buck converter requiring only 4 external components (inductor, diode, input/output caps) - simplifies layout and reduces layer count. Use Value: TO-220 package allows direct heatsinking to chassis; 52 kHz switching enables small, low-cost magnetics and reduces EMI filter size vs. higher-frequency alternatives. |
Use Scenario: Reducing 12 V or 24 V input to ~4.5 V prior to low-noise LDOs powering analog front-ends or RF sections. IC Role / Device Role / Timing Role: Efficient pre-regulator stepping down bulk voltage with minimal dropout - lowers power dissipation in downstream LDOs. Use Value: 75%+ efficiency at full load cuts pre-LDO input power by >50% vs. direct 12 V → 3.3 V linear regulation, enabling smaller LDO packages and lower thermal stress. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2576HVT-3.3 | Wider input range (4–60 V) and higher max junction temperature (+150 °C); same pinout and 3.3 V output. | Better suited for automotive cold-crank (4 V) or high-temp industrial environments (>125 °C ambient). | Select when input can dip below 7 V or ambient exceeds 85 °C; otherwise LM2576T-3.3G offers cost and footprint parity. |
| MP1584EN-LF-Z | Higher switching frequency (1.5 MHz), smaller solution size, but lower max current (3 A typ. derated), no integrated thermal shutdown flag. | Preferred for space-constrained consumer electronics; less robust for sustained 3 A industrial loads without careful thermal design. | Choose for compact PCBs where inductor size dominates; avoid if long-term 3 A continuous operation or fault resilience is critical. |
Compared with LM2576HVT-3.3, the LM2576T-3.3G trades input voltage headroom for cost and legacy design compatibility; compared with MP1584EN-LF-Z, it prioritizes ruggedness and thermal safety over miniaturization - making it optimal for industrial power stages where reliability trumps board area.
Availability
LM2576T-3.3G is available at Aetrix Electronics and suitable for industrial PLCs, embedded microcontroller power supplies, on-card DC-DC conversion, and pre-regulator applications requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.
Supply support for LM2576T-3.3G 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 (Nasdaq: ON) is a global semiconductor leader delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The LM2576 series was engineered as a rugged, easy-to-use buck regulator family targeting cost-sensitive industrial and embedded power designs - emphasizing minimal external components, integrated protection, and compatibility with standard magnetics.
FAQ
What is the maximum input voltage rating for the LM2576T-3.3G?
The LM2576T-3.3G has a maximum supply voltage rating of 45 V, but its recommended operating input range is 7.0 V to 40 V per the datasheet's operating ratings. Exceeding 40 V may trigger internal protection or degrade long-term reliability, even though absolute maximum rating is 45 V. Always maintain ≥1 V margin below 45 V in production designs using LM2576T-3.3G.
Does the LM2576T-3.3G require an external feedback resistor network?
No - the LM2576T-3.3G is a fixed-output variant with an internal resistive divider set to 3.3 V. Pin 4 (Feedback) is not accessible for external adjustment; it connects directly to the internal error amplifier reference node. This eliminates resistor selection errors and improves output accuracy vs. adjustable versions, confirming the design simplicity stated in the LM2576T-3.3G datasheet.
Can the LM2576T-3.3G drive a 3.0 A load continuously at 125 °C ambient temperature?
Yes - the LM2576T-3.3G is rated for continuous 3.0 A output across −40 °C to +125 °C junction temperature. However, achieving this at 125 °C ambient requires adequate heatsinking: with RθJC = 5.0 °C/W and max TJ = 150 °C, allowable temperature rise is 25 °C, demanding ≤5 °C/W total system thermal resistance (heatsink + interface). Real-world validation confirms LM2576T-3.3G sustains 3 A at 125 °C with proper TO-220 heatsink mounting.
What is the purpose of the ON/OFF pin (Pin 5) on the LM2576T-3.3G?
Pin 5 (ON/OFF) provides TTL-compatible logic control: applying ≥2.2 V (25 °C) disables the internal switch, reducing total input current to 80 µA typical - enabling low-power sleep modes. Pulling it low or leaving it open enables regulation. This function is fully characterized in the LM2576T-3.3G datasheet's Electrical Characteristics table and supports precise power sequencing in multi-rail systems.
Which catch diode is recommended for use with the LM2576T-3.3G in a 12 V input, 3 A application?
The onsemi datasheet recommends the MBR360 Schottky diode for 12 V input, 3 A operation - selected for its 60 V reverse voltage rating (≥1.25×12 V), 3.0 A forward current, and low VF to minimize conduction loss. Table 1 in the LM2576T-3.3G datasheet explicitly lists MBR360 as a qualified part, and its 0.65 V typical forward drop directly improves overall efficiency.
LM2576T-3.3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-220-5
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive or Negative
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 7V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 3A
- 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
LM2576T-3.3G FAQ
1.How can I place an order for LM2576T-3.3G through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2576T-3.3G 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 LM2576T-3.3G reliable?
The price and inventory of LM2576T-3.3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2576T-3.3G is usually 5 days.
3.What payment methods are accepted for LM2576T-3.3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2576T-3.3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2576T-3.3G?
LM2576T-3.3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2576T-3.3G 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 LM2576T-3.3G?
For technical support, including LM2576T-3.3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2576T-3.3G requirements.
6.How does Aetrix verify that LM2576T-3.3G is sourced from the original manufacturer or authorized distributors?
All LM2576T-3.3G 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 LM2576T-3.3G meets industry standards.
7.What is the process for return or replacement of LM2576T-3.3G?
All LM2576T-3.3G units undergo pre-shipment inspection (PSI). If there is an issue with LM2576T-3.3G, 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 LM2576T-3.3G part is unused and in its original packaging.
Return procedure for LM2576T-3.3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM2576T-3.3G Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
