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Texas Instruments LM2574N-5.0
- Part No.:
- LM2574N-5.0
- Manufacturer:
- Texas Instruments
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
LM2574N-5.0.pdf
- Description:
- IC REG BUCK 5V 500MA 8PDIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,906
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Product details
Overview
LM2574N-5.0 from Texas Instruments (formerly National Semiconductor) is a monolithic 0.5A step-down (buck) switching voltage regulator in an 8-pin DIP package, delivering a fixed 5.0V output with ±4% tolerance over line and load, 52 kHz fixed-frequency operation, and internal current limiting and thermal shutdown. It replaces linear regulators in industrial power supplies requiring efficient 5V rail generation from up to 40V input.
For engineers reviewing the LM2574N-5.0 datasheet, LM2574N-5.0 pinout, LM2574N-5.0 application, or LM2574N-5.0 equivalent, this page provides verified technical context, real-world design meaning for key specs, validated pin functions, confirmed alternatives with functional differences, and supply support for production-grade embedded power designs.
Technical Context
The LM2574N-5.0 integrates a PWM controller, power switch, oscillator, error amplifier, and protection circuitry into a single IC. Its fixed 5.0V output is internally trimmed and does not require external feedback resistors. The 52 kHz oscillator enables use of low-cost, high-saturation-current inductors and standard electrolytic capacitors.
It operates in continuous conduction mode at full load (0.5A) with typical efficiency of 77% at VIN = 12V, and transitions to discontinuous mode under light loads. Protection includes cycle-by-cycle current limiting (1.0A peak), thermal shutdown, and TTL-compatible ON/OFF control with 50 µA standby current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 5.0V ±4% over −40°C to +125°C, 7V–40V input, 0.1A–0.5A load - ensures stable logic rail without trimming or feedback network. |
| Max Output Current | 0.5A DC - supports microcontroller cores, sensors, and interface ICs without external current boosting. |
| Input Voltage Range | 40V max (LM2574 series), 7V min - compatible with 12V/24V industrial buses and automotive battery-supplied systems with transient suppression. |
| Switching Frequency | 52 kHz fixed - enables use of low-ESR aluminum electrolytics and off-the-shelf 330 µH inductors (e.g., Pulse PE-52627) without EMI filtering complexity. |
| Efficiency | 77% typical at VIN = 12V, IOUT = 0.5A - reduces thermal load vs. linear regulators; PCB copper traces suffice as heatsink. |
| Standby Current | 50 µA typical at OFF pin = 5V - enables low-power sleep modes in battery-backed or energy-conscious systems. |
| Protection Features | Cycle-by-cycle current limit (1.0A peak), thermal shutdown, and output short-circuit robustness - eliminates need for external fault-handling circuitry. |
Pinout & Package
LM2574N-5.0 is housed in an 8-pin plastic dual in-line package (DIP), NS package code N08A, with exposed pad soldered to PCB for thermal enhancement. Pin 1 is bottom-left corner when notch faces up.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VIN) | Input voltage supply | Accepts 7–40V DC; requires ≥22 µF input capacitor near pin for stability and ripple suppression. |
| 2 (GND) | Power ground reference | Common return for input/output capacitors, inductor, and catch diode; must be low-inductance connection. |
| 3 (OUT) | Switch node / power switch output | Drives external catch diode and inductor; carries pulsed 0.5A current; layout critical for EMI control. |
| 4 (GND) | Power ground reference | Second ground pin for improved thermal and current path; must connect directly to same ground plane as Pin 2. |
| 5 (FEEDBACK) | Internal voltage reference connection | No connection required - internally tied to 5.0V output; unused in fixed-output versions. |
| 6 (ON/OFF) | TTL-compatible enable/disable control | Logic high (>2.2V) enables regulation; logic low (<1.2V) disables output and reduces quiescent current to 50 µA. |
| 7 (GND) | Power ground reference | Third ground pin; all GND pins must be bonded to minimize impedance and thermal resistance (θJA = 72°C/W with 4 in² copper). |
| 8 (GND) | Power ground reference | Fourth ground pin; soldered to PCB for heat transfer - no internal connection but essential for thermal performance. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 5.0V output | Eliminates external resistor divider, reducing BOM count and layout sensitivity while guaranteeing ±4% accuracy across temperature and load. |
| Integrated 0.5A power switch | Enables complete buck converter with only four external components: inductor, catch diode, input cap, and output cap - accelerates prototyping. |
| 52 kHz fixed-frequency oscillator | Permits use of low-cost, high-current toroidal or bobbin-core inductors and avoids audible noise or RF interference bands. |
| TTL shutdown capability | Supports system-level power sequencing and low-power sleep states with <50 µA standby current - critical for portable and IoT edge devices. |
| Thermal shutdown + current limit | Provides autonomous fault recovery without external monitoring circuitry - protects against overload, short-circuit, and ambient overheating. |
Applications
| Industrial PLC Power Supply | Embedded Microcontroller Board |
|---|---|
Use Scenario: Generating clean 5V rail from 24V DC field bus for programmable logic controller I/O modules. IC Role / Device Role / Timing Role: Primary step-down regulator supplying core logic and communication peripherals. Use Value: High efficiency (77%) minimizes heat buildup in sealed enclosures; 40V input rating accommodates 24V bus transients without derating. |
Use Scenario: On-board 5V supply for ARM Cortex-M4 MCU, SPI flash, and RS-485 transceivers on a compact industrial sensor node. IC Role / Device Role / Timing Role: Main power conversion stage enabling single-rail board architecture. Use Value: Fixed 5.0V output eliminates calibration overhead; DIP package allows manual rework and through-hole reliability in vibration-prone environments. |
| Automotive Body Control Module | Test Equipment Auxiliary Rail |
Use Scenario: Deriving regulated 5V from vehicle battery (9–16V nominal, up to 40V during load dump) for interior lighting controllers. IC Role / Device Role / Timing Role: Pre-regulator feeding low-noise LDOs for analog sensor interfaces. Use Value: Wide 7–40V input range handles cold-crank and load-dump conditions; thermal shutdown prevents latch-up during sustained overloads. |
Use Scenario: Standalone 5V source in benchtop test fixtures powering DUTs with variable input sources. IC Role / Device Role / Timing Role: Isolated, self-contained buck converter with ON/OFF control for remote power cycling. Use Value: TTL-compatible enable pin allows integration with test sequencers; 0.5A output supports multi-peripheral DUTs without external boost stages. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2575N-5.0 | Higher 1A output current, 52 kHz frequency, same DIP-8 package; requires larger inductor (100 µH vs. 330 µH) due to higher peak current. | Better suited for 5V rails driving multiple peripherals or higher-current logic families (e.g., 74AC, FPGA I/O banks). | Select LM2575N-5.0 if >0.5A sustained load or tighter transient response is required; verify inductor saturation current rating. |
| MC33063AP | Adjustable output, 1.5A switch, 100 kHz frequency, DIP-8; requires external feedback resistors and timing capacitor; lower efficiency (~70% at 0.5A). | Used where flexible output voltage (e.g., 3.3V/5V/12V) or cost-sensitive BOM is prioritized over fixed-voltage simplicity. | Choose MC33063AP only when output voltage flexibility outweighs added component count and reduced efficiency; not drop-in compatible. |
Compared with LM2574N-5.0, LM2575N-5.0 offers higher current headroom but demands revised magnetics, while MC33063AP trades fixed-output convenience for configurability and lower efficiency - both require schematic and layout changes.
Availability
LM2574N-5.0 is available at Aetrix Electronics and suitable for industrial PLC power supplies, embedded microcontroller boards, automotive body control modules, and test equipment auxiliary rails requiring stable component supply with long-term lifecycle assurance.
Supply support for LM2574N-5.0 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 acquired National Semiconductor in 2011 and maintains full technical support, datasheets, and legacy product availability for the SIMPLE SWITCHER™ portfolio.
The LM2574N-5.0 belongs to TI's SIMPLE SWITCHER™ family of integrated buck regulators, designed specifically for cost-sensitive, space-constrained industrial and embedded power applications requiring minimal external components and proven reliability.
FAQ
What is the maximum input voltage rating for LM2574N-5.0?
The LM2574N-5.0 has a maximum input voltage rating of 40V, as specified in its Absolute Maximum Ratings table. This allows safe operation from 24V industrial buses and automotive systems with transient suppression. Exceeding 40V risks permanent damage; for 60V input applications, the LM2574HV-5.0 variant must be used instead of the standard LM2574N-5.0.
Does LM2574N-5.0 require external feedback resistors to set its output voltage?
No, the LM2574N-5.0 does not require external feedback resistors. Its 5.0V output is internally trimmed and fixed at the silicon level. Pin 5 (FEEDBACK) is internally connected to the output and must remain unconnected in PCB layout - unlike the adjustable LM2574-ADJ version, which relies on external R1/R2 dividers.
What is the typical efficiency of LM2574N-5.0 at full load?
The LM2574N-5.0 achieves 77% typical efficiency at VIN = 12V and IOUT = 0.5A, as measured per the official datasheet test conditions. Efficiency varies with input voltage and load: it rises to ~88% at VIN = 15V for the 12V-output variant, but remains ~77% for the 5V version across its recommended input range (7–40V).
Can LM2574N-5.0 be used in discontinuous conduction mode?
Yes, the LM2574N-5.0 operates reliably in both continuous and discontinuous conduction modes. At light loads (<~100 mA), inductor current drops to zero each cycle - a normal, stable condition that reduces switching losses. The 52 kHz oscillator and internal compensation ensure loop stability without external tuning in either mode.
What thermal management is required for LM2574N-5.0 at 0.5A output?
At 0.5A output and 12V input, LM2574N-5.0 dissipates ~3.5W. With its N-package θJA of 72°C/W (using 4 in² of 1 oz. copper), junction temperature rise is ~250°C above ambient - exceeding 150°C max. Therefore, minimum 1 in² copper pour is mandatory; 4 in² is strongly recommended. Pins 2, 4, 7, and 8 must be soldered to ground plane for effective heat transfer.
LM2574N-5.0 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- 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):
- 5V
- Voltage - Output (Max):
- -
- Current - Output:
- 500mA
- Frequency - Switching:
- 52kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
LM2574N-5.0 FAQ
1.How can I place an order for LM2574N-5.0 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2574N-5.0 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 LM2574N-5.0 reliable?
The price and inventory of LM2574N-5.0 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2574N-5.0 is usually 5 days.
3.What payment methods are accepted for LM2574N-5.0?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2574N-5.0 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2574N-5.0?
LM2574N-5.0 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2574N-5.0 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 LM2574N-5.0?
For technical support, including LM2574N-5.0 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2574N-5.0 requirements.
6.How does Aetrix verify that LM2574N-5.0 is sourced from the original manufacturer or authorized distributors?
All LM2574N-5.0 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 LM2574N-5.0 meets industry standards.
7.What is the process for return or replacement of LM2574N-5.0?
All LM2574N-5.0 units undergo pre-shipment inspection (PSI). If there is an issue with LM2574N-5.0, 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 LM2574N-5.0 part is unused and in its original packaging.
Return procedure for LM2574N-5.0:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM2574N-5.0 Tags
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TPS562201DDCR
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MC33063ADR
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AZ34063UMTR-G1
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MC34063EBD-TR
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