My Inquiry
My Account
Texas Instruments LM2576T-3.3
- Part No.:
- LM2576T-3.3
- Manufacturer:
- Texas Instruments
- Package:
- TO-220-5
- Datasheet:
-
LM2576T-3.3.pdf
- Description:
- IC REG BUCK 3.3V 3A TO220-5
- Quantity:
- Payment:
- Shipping:
Inventory:3,778
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM2576T-3.3 from Texas Instruments is a monolithic 3-A non-synchronous step-down DC-DC switching regulator in TO-220-5 (KC) package, delivering fixed 3.3-V output with ±4% tolerance over line and load, 52-kHz fixed-frequency operation, and TTL-compatible ON/OFF control. It replaces linear regulators in industrial power supplies, motor drives, and test equipment where thermal efficiency and minimal external components are critical.
For engineers reviewing the LM2576T-3.3 datasheet, LM2576T-3.3 pinout, LM2576T-3.3 application, or LM2576T-3.3 equivalent, key selection considerations include input voltage range (up to 40 V), 3-A continuous output current capability, thermal performance in TO-220 package (RθJA = 32.4°C/W), and integrated cycle-by-cycle current limiting with thermal shutdown.
Technical Context
The LM2576T-3.3 implements a fixed-frequency buck topology with internal 52-kHz oscillator, bandgap reference, error amplifier, and NPN power switch. Its feedback loop uses direct connection of the FEEDBACK pin to output capacitor for fixed-output variants, eliminating external resistor dividers.
Functional modes include active regulation (ON/OFF pin < 1.2 V), shutdown (ON/OFF pin > 1.4 V, ISTBY = 50 μA typ), and fault protection via cycle-by-cycle current limit (ICL = 4.2–6.9 A) and thermal shutdown. Oscillator frequency drops to ~11 kHz under short-circuit to reduce average power dissipation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3 V ±4% over full operating temperature (−40°C to +125°C) and load (0.5–3 A) |
| Input Voltage Range | 4 V to 40 V - supports wide-input industrial rails without pre-regulation |
| Output Current | 3 A continuous - enables single-chip supply for microcontrollers, FPGAs, and peripheral ICs |
| Switching Frequency | 52 kHz ±10% - balances EMI, inductor size, and efficiency; reduces need for high-frequency EMI filtering |
| Efficiency | 75% at 12 VIN/3.3 VOUT/3 A - significantly lowers thermal load vs. linear regulators |
| Standby Current | 50 μA typical at shutdown - enables low-power system-level sleep modes |
| Saturation Voltage | 1.4–2.0 V at 3 A - defines minimum dropout and impacts conduction losses |
| Current Limit | 4.2–6.9 A - provides robust overload protection without external sensing |
Pinout & Package
LM2576T-3.3 is housed in a TO-220-5 (KC) package with exposed tab thermally and electrically connected to GROUND. The tab must be mounted to a heatsink or large copper pour for thermal management per RθJA = 32.4°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VIN | Power input | Connects to high-side transistor collector; requires short, low-inductance path to input capacitor |
| 2 - OUTPUT | Switching node | Emitter of internal NPN switch; connects directly to inductor and catch diode cathode |
| 3 - GROUND | Power and signal reference | Common return for input/output capacitors and feedback; shortest possible trace to VIN and OUTPUT |
| 4 - FEEDBACK | Regulation sense | Internally tied to output for fixed 3.3-V version; no external divider needed |
| 5 - ON/OFF | Enable control | TTL-compatible logic input: <1.2 V = ON, >1.4 V = OFF; 50-μA standby current when high |
| TAB | Thermal & electrical ground | Internally connected to GROUND pin; must be soldered to heatsink or PCB copper for thermal relief |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 3.3-V output | Eliminates external feedback resistors, reducing BOM count and layout sensitivity |
| Integrated NPN switch | Reduces external component count to just four: input cap, output cap, inductor, catch diode |
| Cycle-by-cycle current limit | Prevents inductor saturation and switch failure during transient overloads without external sensing |
| TTL shutdown interface | Enables seamless integration with microcontroller GPIOs for system-level power sequencing |
| Thermal shutdown protection | Automatically disables switching if junction temperature exceeds safe limit, preventing permanent damage |
| Standard inductor compatibility | Works with off-the-shelf shielded power inductors (e.g., 33–100 µH), simplifying design validation |
Applications
| Industrial Motor Drive Power Supply | Embedded System Core Rail |
|---|---|
Use Scenario: Provides 3.3-V bias for gate drivers, position sensors, and MCU peripherals in 24-V DC-fed brushless motor controllers. IC Role / Device Role / Timing Role: Primary non-isolated buck converter delivering regulated 3.3-V rail with fast transient response to PWM-driven load steps. Use Value: Delivers 3 A continuously with 75% efficiency at 24 VIN, reducing heat sink size by >70% versus linear solution. | Use Scenario: Powers ARM Cortex-M7 microcontroller and DDR memory interface in network appliance with 12-V backplane input. IC Role / Device Role / Timing Role: Fixed-output step-down regulator supplying stable 3.3-V core voltage with ±4% accuracy across temperature and load. Use Value: Maintains regulation during 0.5–3 A dynamic load swings with <100-mV output undershoot, verified per Figure 6-19. |
| Test Equipment Auxiliary Supply | Appliance Control Board PSU |
Use Scenario: Generates clean 3.3-V rail for analog front-end ADCs and digital logic in portable multimeters and oscilloscope modules. IC Role / Device Role / Timing Role: Low-noise buck regulator with optional LC ripple filter (Figure 7-4), minimizing switching artifacts on sensitive measurement paths. Use Value: Achieves <50 mVPP output ripple at 3 A using standard 100-µH inductor and 220-µF output capacitor. | Use Scenario: Supplies 3.3-V logic rail for touch controller, display driver, and Wi-Fi module in smart refrigerator control board. IC Role / Device Role / Timing Role: Robust main DC-DC converter operating from 12–24 V battery or adapter input with built-in thermal and overload protection. Use Value: Survives repeated 100-ms short-circuit events via frequency foldback (11 kHz) and thermal shutdown, per Section 7.4.3. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2576T-3.3HV | Higher max input voltage (60 V vs. 40 V); identical pinout, package, and 3.3-V output spec | Suitable for 48-V industrial or automotive-derived systems where input transients exceed 40 V | Select LM2576T-3.3HV only if input voltage may reach 48–60 V; otherwise LM2576T-3.3 offers same performance at lower cost |
| LMR51430RNXR | Synchronous buck (vs. non-synchronous), 4.5–36-V input, 3-A, 500-kHz/1.1-MHz selectable, smaller 3-mm × 2-mm WSON | Requires external MOSFETs replaced by integrated high/low-side FETs; higher efficiency (>90%) but needs more complex layout | Choose LMR51430RNXR for new designs prioritizing efficiency, size, and modern synchronous architecture; LM2576T-3.3 remains optimal for legacy compatibility and simplicity |
Compared with LM2576T-3.3HV, the original LM2576T-3.3 trades input voltage headroom for cost and thermal margin in 12–24-V systems; compared with LMR51430RNXR, it sacrifices efficiency and footprint for design simplicity, proven reliability, and minimal external component count.
Availability
LM2576T-3.3 is available at Aetrix Electronics and suitable for industrial motor drives, embedded system power rails, test equipment auxiliary supplies, and appliance control boards requiring stable component supply and long-term manufacturability.
Supply support for LM2576T-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
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management technologies, with decades of expertise in reliable, high-volume power conversion ICs.
The LM2576 series belongs to TI's SIMPLE SWITCHER® portfolio, designed specifically for engineers needing rugged, easy-to-use DC-DC buck regulators with minimal external components and proven field reliability in industrial and commercial applications.
FAQ
What is the maximum input voltage rating for the LM2576T-3.3?
The LM2576T-3.3 has an absolute maximum input voltage of 45 V and a recommended maximum operating input voltage of 40 V. Exceeding 40 V risks violating recommended operating conditions and may trigger thermal shutdown or reduce lifetime reliability. For 48-V systems, the LM2576T-3.3HV variant (60-V max) is specified.
Does the LM2576T-3.3 require an external feedback resistor network?
No. The LM2576T-3.3 is a fixed-output variant: its FEEDBACK pin is internally connected to the output stage, so no external resistor divider is needed. This simplifies layout, improves stability, and eliminates resistor tolerance errors affecting output accuracy - unlike the adjustable LM2576ADJ version.
How does the ON/OFF pin function on the LM2576T-3.3?
The ON/OFF pin on the LM2576T-3.3 is TTL-compatible: pulling it below 1.2 V (typically to GROUND) enables regulation; raising it above 1.4 V (e.g., to 5 V) places the device in shutdown mode with 50-μA typical standby current. The pin must never be left floating, as this may cause erratic startup or oscillation.
What thermal management is required for the LM2576T-3.3 at full 3-A load?
At 3 A and 12-V input, the LM2576T-3.3 dissipates ~2.7 W. With RθJA = 32.4°C/W in TO-220-5, junction temperature rise is ~87°C above ambient. To maintain TJ ≤ 125°C, ambient must stay ≤ 38°C unless a heatsink or ≥1 in² copper pour is used. Thermal relief via the exposed tab is mandatory for sustained 3-A operation.
Can the LM2576T-3.3 drive a 3-A load continuously without derating?
Yes - the LM2576T-3.3 is rated for 3-A continuous output current under specified conditions: TA ≤ 25°C, proper thermal management (heatsink or large copper area), and input voltage within 6–40 V. At higher ambient temperatures or with inadequate heatsinking, output current must be reduced per the thermal derating curve in Figure 6-17 of the datasheet.
LM2576T-3.3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- TO-220-5
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- 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-3.3 FAQ
1.How can I place an order for LM2576T-3.3 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2576T-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 LM2576T-3.3 reliable?
The price and inventory of LM2576T-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 LM2576T-3.3 is usually 5 days.
3.What payment methods are accepted for LM2576T-3.3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2576T-3.3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2576T-3.3?
LM2576T-3.3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2576T-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 LM2576T-3.3?
For technical support, including LM2576T-3.3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2576T-3.3 requirements.
6.How does Aetrix verify that LM2576T-3.3 is sourced from the original manufacturer or authorized distributors?
All LM2576T-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 LM2576T-3.3 meets industry standards.
7.What is the process for return or replacement of LM2576T-3.3?
All LM2576T-3.3 units undergo pre-shipment inspection (PSI). If there is an issue with LM2576T-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 LM2576T-3.3 part is unused and in its original packaging.
Return procedure for LM2576T-3.3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM2576T-3.3 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
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…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
