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Texas Instruments LM2574M-12
- Part No.:
- LM2574M-12
- Manufacturer:
- Texas Instruments
- Package:
- 14-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
LM2574M-12.pdf
- Description:
- IC REG BUCK 12V 500MA 14SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,955
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Product details
Overview
LM2574M-12 from Texas Instruments (formerly National Semiconductor) is a monolithic 0.5A step-down (buck) switching voltage regulator with fixed 12V output, 52 kHz internal oscillator, and integrated power switch. It operates from 15V to 40V input, delivers ±4% output voltage accuracy over line/load/temperature, and supports thermal shutdown and cycle-by-cycle current limiting. It is used in on-card DC-DC conversion for industrial control and embedded power rails.
For engineers reviewing the LM2574M-12 datasheet, LM2574M-12 pinout, LM2574M-12 application, or LM2574M-12 equivalent, key selection criteria include input voltage range (15–40V), guaranteed 0.5A output current, fixed 12V output tolerance, thermal resistance (78°C/W for M-package), and compatibility with standard off-the-shelf inductors (e.g., 330 µH).
Technical Context
The LM2574M-12 implements a fixed-frequency, current-mode buck topology with internal 52 kHz oscillator and integrated NPN power switch. Its feedback loop uses a resistive divider network (internal for fixed versions) to regulate output voltage without external compensation components.
It features TTL-compatible ON/OFF control (50 µA standby current), cycle-by-cycle current limiting (1.0 A peak), and thermal shutdown at 150°C junction temperature. The device requires only four external components: input capacitor, output capacitor, catch diode, and inductor - all optimized for simplicity and board-area efficiency.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 12 V ±4% over full operating range (15–40 VIN, 0.1–0.5 A, −40°C to +125°C) |
| Max Output Current | 0.5 A continuous - sufficient for mid-power microcontroller or sensor subsystem rails |
| Input Voltage Range | 15 V to 40 V - compatible with 24 V industrial bus and unregulated 28 V aircraft systems |
| Switching Frequency | 52 kHz fixed - enables use of low-cost, high-saturation-current inductors (e.g., Pulse PE-52627) |
| Efficiency | 88% at VIN = 15 V, IOUT = 0.5 A - reduces thermal load vs. linear regulators; PCB copper acts as primary heatsink |
| Thermal Resistance | 78 °C/W (Junction-to-Ambient, M-package with 4 in² copper) - enables operation without external heatsink at ≤0.5 A |
| Standby Current | 50 µA typical (ON/OFF pin = 5 V) - supports low-power sleep modes in battery-backed systems |
Pinout & Package
LM2574M-12 is housed in a 14-lead wide surface-mount (WM) package (NS package code M14B), thermally enhanced for high-power density applications. Pin 1 is marked by a beveled corner; pins are arranged in two rows (7 per side). Thermal performance relies on soldering exposed pad (Pin 14) to ≥4 in² of 1 oz. copper.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VIN) | Input Supply | Accepts 15–40 V DC; bypassed externally with ≥22 µF electrolytic capacitor |
| 2 (GND) | Power Ground | Common return for input/output paths and internal circuitry; tied to thermal pad |
| 3 (OUT) | Switch Node | Drives external catch diode and inductor; carries pulsed 0.5 A current; high dI/dt node |
| 4 (FEEDBACK) | Regulation Sense | Internally connected to 12 V divider; not accessible - fixed-output version has no external feedback path |
| 5 (ON/OFF) | Enable Control | TTL-compatible shutdown input; <1.2 V = ON, >2.2 V = OFF; draws 50 µA in standby |
| 6 (GND) | Signal Ground | Separate ground reference for feedback and control logic; recommended to tie to Pin 2 at single point |
| 7–13 | No Internal Connection | Unused pins; electrically isolated but must be soldered to PCB for mechanical stability and thermal conduction |
| 14 (Thermal Pad) | Thermal Interface | Direct thermal path to PCB copper; required for rated 0.5 A operation; must be soldered to ≥4 in² copper area |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 12 V output | Eliminates external resistor divider - reduces BOM count and layout sensitivity for dedicated 12 V rail generation |
| Integrated NPN switch | Enables complete buck regulator with only 4 external parts - simplifies design and improves reliability vs. discrete switch solutions |
| 52 kHz oscillator | Optimizes inductor size/cost trade-off - avoids audible noise while enabling use of low-DCR, high-current off-the-shelf inductors |
| TTL shutdown | Allows system-level power sequencing and low-quiescent sleep states without external level-shifting circuitry |
| Thermal + current protection | Prevents damage during overload, short-circuit, or inadequate heatsinking - supports robust field deployment without derating |
Applications
| Industrial PLC I/O Module Power | Automotive Body Control Unit (BCU) |
|---|---|
Use Scenario: Generating stable 12 V supply for digital I/O drivers, analog sensors, and CAN transceivers in programmable logic controller backplanes. IC Role / Device Role / Timing Role: Primary step-down regulator converting 24 V bus to isolated 12 V rail; provides regulated power for mixed-signal subsystems. Use Value: 88% efficiency minimizes heat buildup in sealed enclosures; ±4% output tolerance ensures reliable logic-level compatibility across temperature. |
Use Scenario: Powering microcontroller peripherals (LIN transceivers, LED drivers, window motor controllers) from vehicle 24 V battery with load dump immunity. IC Role / Device Role / Timing Role: Pre-regulator stepping 24 V down to 12 V before LDOs - handles wide input transients and reduces thermal stress on downstream regulators. Use Value: 40 V max input withstands ISO 7637-2 pulse 5a (load dump); thermal shutdown prevents latch-up during sustained overloads. |
| Medical Infusion Pump Motor Drive | Test & Measurement Equipment Auxiliary Rail |
Use Scenario: Supplying 12 V to stepper motor drivers and real-time MCU in portable infusion pumps requiring low EMI and long battery life. IC Role / Device Role / Timing Role: High-efficiency DC-DC converter replacing linear regulators to extend battery runtime and reduce thermal mass. Use Value: 50 µA standby current enables deep-sleep modes; fixed frequency allows predictable EMI filtering; 0.5 A headroom supports motor surge currents. |
Use Scenario: Providing clean 12 V bias for op-amp signal chains, ADC references, and FPGA configuration circuits in benchtop analyzers. IC Role / Device Role / Timing Role: Isolated intermediate rail generator - separates noisy digital power from precision analog sections via inductor-based filtering. Use Value: Low output ripple (<50 mV p-p typical with 220 µF output cap) preserves SNR; 52 kHz switching avoids interference with 10–100 MHz measurement bandwidths. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2576-12 | Higher 3 A output current; 52 kHz frequency; requires larger inductor (100 µH vs. 330 µH); higher quiescent current (10 mA vs. 5 mA) | Better suited for higher-current loads (>0.5 A); less suitable for space-constrained designs due to larger magnetics | Select LM2576-12 only if load exceeds 0.5 A or transient current demands require greater headroom. |
| TPS54202DR | Synchronous 2 A buck; 400–2500 kHz adjustable frequency; 3.5–28 V input; requires external MOSFETs replaced by integrated FETs; no thermal pad | Enables smaller solution size and higher efficiency at light loads; lacks built-in thermal pad for high ambient operation | Choose TPS54202DR for compact, high-efficiency designs where PCB area is critical and ambient temperature remains <85°C. |
Compared with LM2576-12 and TPS54202DR, the LM2574M-12 offers optimal balance of simplicity, thermal robustness (via M14B thermal pad), and cost for fixed 12 V, ≤0.5 A applications - especially where reliability under industrial temperature extremes and minimal external component count are prioritized.
Availability
LM2574M-12 is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and medical device power supplies requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LM2574M-12 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, documentation, and manufacturing continuity for the SIMPLE SWITCHER™ product line.
The LM2574 series was designed specifically for cost-sensitive, medium-power DC-DC conversion in industrial, automotive, and instrumentation applications - emphasizing ease of use, thermal resilience, and minimal external component count.
FAQ
What is the maximum input voltage rating for the LM2574M-12?
The LM2574M-12 has an absolute maximum input voltage of 45 V and a recommended operating maximum of 40 V. Exceeding 40 V risks violating the specified output voltage accuracy and thermal limits. For applications with higher transient voltages (e.g., automotive load dump), the LM2574HV-12 variant - rated up to 60 V operating input - is the appropriate alternative. Always verify input transient conditions against the LM2574M-12 datasheet's Absolute Maximum Ratings table.
Can the LM2574M-12 be used in discontinuous conduction mode (DCM)?
Yes, the LM2574M-12 operates reliably in both continuous and discontinuous conduction modes. DCM occurs naturally at light loads (<~100 mA) and is explicitly supported in the datasheet's Typical Performance Characteristics. No design changes are needed - the IC automatically adjusts duty cycle and maintains regulation. However, output ripple increases in DCM, so designers should verify ripple requirements using the formula ΔVOUT = ΔIIND × ESRCOUT for their specific inductor and capacitor.
What inductor value is recommended for the LM2574M-12 at 0.5 A output?
The LM2574M-12 datasheet specifies 330 µH for 0.5 A continuous operation with 15–40 V input (Figure 6, Inductor Selection Guide). Recommended part numbers include Pulse Engineering PE-52627, Renco RL-1284-330-43, or NPI NP5920/5921. These inductors are rated for ≥1.5×0.5 A = 0.75 A saturation current and 52 kHz operation. Using a lower-value inductor may cause excessive ripple or instability; higher values increase size and cost without benefit.
Does the LM2574M-12 require external compensation components?
No, the LM2574M-12 includes internal frequency compensation and is designed for unconditional stability with the standard 4-component configuration (input cap, output cap, catch diode, inductor). No external compensation network is needed - unlike adjustable regulators or synchronous buck controllers. This simplifies layout, reduces BOM count, and eliminates tuning effort. Stability is verified across all operating conditions in the datasheet's Typical Performance Characteristics.
How is thermal performance affected by PCB copper area for the LM2574M-12?
Thermal resistance of the LM2574M-12 drops from 102°C/W (with 1 in² copper) to 78°C/W (with 4 in² copper), directly impacting maximum sustainable output current. At 0.5 A and 40 VIN, junction temperature rise is ~39°C with 4 in² copper - well within the 125°C max operating limit. Reducing copper area increases thermal resistance proportionally; insufficient copper can trigger thermal shutdown. The thermal pad (Pin 14) must be fully soldered to the copper plane for effective heat transfer.
LM2574M-12 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 14-SOIC (0.295", 7.50mm Width)
- 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):
- 12V
- Voltage - Output (Max):
- -
- Current - Output:
- 500mA
- Frequency - Switching:
- 52kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-SOIC
LM2574M-12 FAQ
1.How can I place an order for LM2574M-12 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2574M-12 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 LM2574M-12 reliable?
The price and inventory of LM2574M-12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2574M-12 is usually 5 days.
3.What payment methods are accepted for LM2574M-12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2574M-12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2574M-12?
LM2574M-12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2574M-12 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 LM2574M-12?
For technical support, including LM2574M-12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2574M-12 requirements.
6.How does Aetrix verify that LM2574M-12 is sourced from the original manufacturer or authorized distributors?
All LM2574M-12 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 LM2574M-12 meets industry standards.
7.What is the process for return or replacement of LM2574M-12?
All LM2574M-12 units undergo pre-shipment inspection (PSI). If there is an issue with LM2574M-12, 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 LM2574M-12 part is unused and in its original packaging.
Return procedure for LM2574M-12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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