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Texas Instruments LM2574M-15/NOPB
- Part No.:
- LM2574M-15/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 14-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
LM2574M-15/NOPB.pdf
- Description:
- IC REG BUCK 15V 500MA 14SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,184
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Product details
Overview
LM2574M-15/NOPB from Texas Instruments (formerly National Semiconductor) is a monolithic 0.5A step-down (buck) switching voltage regulator with fixed 15V output, 52 kHz internal oscillator, 40V maximum input voltage, ±4% output voltage tolerance, and thermal shutdown protection. It replaces linear regulators in industrial power supplies requiring efficient 15V rail generation from higher DC inputs.
For engineers reviewing the LM2574M-15/NOPB datasheet, LM2574M-15/NOPB pinout, LM2574M-15/NOPB application, or LM2574M-15/NOPB equivalent, key selection criteria include guaranteed 0.5A output current, fixed-frequency operation for EMI predictability, TTL-compatible shutdown control, junction-to-ambient thermal resistance of 78°C/W (M package), and compatibility with standard off-the-shelf 330 µH inductors.
Technical Context
The LM2574M-15/NOPB integrates a PWM controller, power switch, oscillator, error amplifier, and current-limit circuit in a single IC. Its fixed 15V output is internally trimmed and does not require external feedback resistors. The 52 kHz oscillator enables use of low-cost, high-saturation-current inductors while maintaining manageable EMI and PCB layout constraints.
Operation relies on cycle-by-cycle current limiting and thermal shutdown for fault protection. Input voltage range spans 18V to 40V for stable 15V output delivery under line and load regulation conditions, with efficiency reaching 88% at 18V input and 0.5A load. Standby quiescent current is 50 µA typical when the ON/OFF pin is pulled high.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 15V ±4% over full temperature and load range - eliminates feedback resistor network and simplifies BOM. |
| Max Output Current | 0.5A continuous - supports mid-power applications such as sensor signal chains and microcontroller peripherals. |
| Input Voltage Range | 18V to 40V - suitable for unregulated 24V industrial rails and automotive battery-derived supplies. |
| Oscillator Frequency | 52 kHz fixed - enables predictable EMI filtering and use of cost-effective, widely available 330 µH inductors. |
| Efficiency | 88% at VIN = 18V, IOUT = 0.5A - reduces thermal load vs. linear regulators, minimizing need for heatsinking. |
| Thermal Resistance | θJA = 78°C/W (M package, 4 in² copper) - enables operation up to +125°C junction temperature with standard PCB copper area. |
| Shutdown Current | 50 µA typical - allows low-power system-level sleep modes without auxiliary LDOs. |
Pinout & Package
LM2574M-15/NOPB is housed in a 14-pin wide-body surface-mount (WM) package (NS package code M14B), thermally enhanced for power dissipation on standard PCB copper.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VIN) | Input supply connection | Accepts 18–40V DC; requires local 22 µF aluminum electrolytic bypass capacitor. |
| 2 (GND) | Power and signal ground reference | Must be connected to low-impedance ground plane; shared return for input/output capacitors and catch diode. |
| 3 (OUT) | Switching node / power switch drain | Drives external catch diode and inductor; high dv/dt node requiring short trace routing. |
| 4 (GND) | Power ground (second pin) | Dual GND pins reduce ground loop inductance; both must be soldered to PCB ground plane. |
| 5 (ON/OFF) | TTL-compatible enable/disable control | Pull ≥2.2V to enable; ≤1.0V to disable; draws only 12 µA max in active state. |
| 6 (GND) | Power ground (third pin) | Third GND pin improves thermal conduction and reduces ground bounce during switching transitions. |
| 7 (GND) | Power ground (fourth pin) | Fourth GND pin further enhances thermal path and minimizes switching noise coupling. |
| 8 (FB) | Feedback input (not used in fixed-output version) | No connection required; leave floating or tie to GND per datasheet guidance for fixed versions. |
| 9–14 (GND) | Additional ground terminals | All six GND pins (pins 2,4,6,7,9–14) are internally bonded to die substrate - critical for thermal performance and EMI control. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 15V output | Eliminates external resistor divider, reducing component count and improving long-term output stability. |
| Integrated cycle-by-cycle current limit | Protects against short-circuit and overload faults without external sensing components; limits peak switch current to 1.0A typical. |
| TTL-compatible ON/OFF control | Enables system-level power sequencing and low-power standby with <50 µA quiescent draw in shutdown mode. |
| Thermal shutdown protection | Automatically disables regulator when junction temperature exceeds ~150°C, preventing permanent damage during sustained overload. |
| 52 kHz fixed-frequency operation | Ensures consistent EMI profile and simplifies filter design; avoids audible noise and enables use of low-cost, high-current inductors. |
Applications
| Industrial Power Supply | Microcontroller System Rail |
|---|---|
|
Use Scenario: Generating a stable 15V supply from an unregulated 24V factory bus for analog front-end instrumentation. IC Role / Device Role / Timing Role: Primary buck regulator providing isolated 15V rail with line/load regulation better than ±1%. Use Value: Replaces inefficient 7815 linear regulator, cutting board-level heat by >70% and eliminating heatsink requirements. |
Use Scenario: Powering op-amps, ADC references, and RS-485 transceivers in a programmable logic controller (PLC) module. IC Role / Device Role / Timing Role: Mid-power DC-DC stage delivering clean, regulated 15V with low output ripple (<50 mVpp). Use Value: Enables compact, fanless PLC design with full thermal margin across −40°C to +85°C ambient. |
| On-Card Switching Regulator | Positive-to-Negative Converter (Buck-Boost) |
|
Use Scenario: Local 15V generation on a dense motor-control PCB where space precludes external DC-DC modules. IC Role / Device Role / Timing Role: Integrated buck controller with built-in switch, reducing footprint vs. discrete controller + MOSFET solutions. Use Value: Achieves 0.5A output in 14-pin WM package with only four external components (inductor, diode, two capacitors). |
Use Scenario: Deriving −15V from a 24V rail for dual-supply op-amp circuits in test equipment. IC Role / Device Role / Timing Role: Configured in inverting buck-boost topology using same external components as buck mode. Use Value: Leverages identical LM2574M-15/NOPB inventory for both positive and negative rail generation, simplifying BOM management. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2574HVM-15/NOPB | Higher 60V max input voltage (vs. 40V); otherwise identical pinout, specs, and package. | Suitable for 48V telecom or automotive cold-crank environments where input may exceed 40V transiently. | Select LM2574HVM-15/NOPB only if input voltage excursions beyond 40V are expected; otherwise LM2574M-15/NOPB offers optimal cost/performance. |
| LM2596S-15 | 3A output current, 150 kHz switching frequency, different pinout and package (TO-263-5), no ON/OFF pin. | Supports higher current loads but requires redesign of inductor, diode, and PCB layout; lacks enable control. | Choose LM2596S-15 only when >0.5A output is required; LM2574M-15/NOPB remains preferred for 0.5A applications needing enable functionality and proven 52 kHz EMI behavior. |
Compared with LM2574HVM-15/NOPB, the LM2574M-15/NOPB trades input voltage headroom for lower cost and identical thermal performance in 24V systems; compared with LM2596S-15, it provides enable control and simpler EMI filtering at lower current capability - making it optimal for cost-sensitive, moderate-power industrial rails.
Availability
LM2574M-15/NOPB is available at Aetrix Electronics and suitable for industrial automation, PLC power subsystems, and embedded sensor interface designs requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for LM2574M-15/NOPB 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 family.
The LM2574M-15/NOPB belongs to TI's SIMPLE SWITCHER™ buck regulator series, designed specifically for ease-of-use in cost-sensitive industrial and embedded power applications where minimal external components and robust fault protection are essential.
FAQ
What is the maximum input voltage rating for the LM2574M-15/NOPB?
The LM2574M-15/NOPB has an absolute maximum input voltage of 45V, but its specified operating input voltage range is 18V to 40V for reliable 15V output regulation. Exceeding 40V may cause out-of-spec output voltage or reduced efficiency; for 48V input systems, the LM2574HVM-15/NOPB variant with 60V max input should be used instead of the LM2574M-15/NOPB.
Does the LM2574M-15/NOPB require external feedback resistors?
No, the LM2574M-15/NOPB is a fixed-output version with internal voltage reference and feedback network trimmed to 15V. Pin 8 (FB) is not connected internally for this variant and should be left unconnected or tied to ground per TI's recommended practice - no external resistors are needed, unlike the adjustable LM2574M-ADJ version.
What inductor value is recommended for the LM2574M-15/NOPB in standard buck configuration?
TI specifies a 330 µH inductor for the LM2574M-15/NOPB in continuous conduction mode with typical 24V input and 0.5A load. Recommended part numbers include Pulse Engineering PE-52627, Renco RL-1284-330, or NPI NP5920/5921 - all rated for ≥1.5×0.5A (0.75A) saturation current and 52 kHz operation.
How does the ON/OFF pin function on the LM2574M-15/NOPB?
The ON/OFF pin (Pin 5) of the LM2574M-15/NOPB provides TTL-compatible enable control: driving it to ≥2.2V enables regulation, while pulling it ≤1.0V disables the output and reduces quiescent current to 50 µA typical. This feature allows precise system-level power sequencing and low-power standby without external logic level shifters.
Is thermal derating required for the LM2574M-15/NOPB at elevated ambient temperatures?
Yes - the LM2574M-15/NOPB's 78°C/W thermal resistance (with 4 in² copper) means junction temperature rises ~39°C at 0.5A full load (PD ≈ 0.5A × 0.9V ≈ 0.45W). At 70°C ambient, TJ ≈ 109°C - within the +125°C max rating. For continuous 85°C ambient, output current should be limited to ~0.35A to maintain TJ ≤ 125°C, per TI's thermal guidelines for the LM2574M-15/NOPB.
LM2574M-15/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 14-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tube
- Product Status:
- Discontinued at Digi-Key
- 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):
- 15V
- 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-15/NOPB FAQ
1.How can I place an order for LM2574M-15/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2574M-15/NOPB 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-15/NOPB reliable?
The price and inventory of LM2574M-15/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2574M-15/NOPB is usually 5 days.
3.What payment methods are accepted for LM2574M-15/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2574M-15/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2574M-15/NOPB?
LM2574M-15/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2574M-15/NOPB 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-15/NOPB?
For technical support, including LM2574M-15/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2574M-15/NOPB requirements.
6.How does Aetrix verify that LM2574M-15/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2574M-15/NOPB 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-15/NOPB meets industry standards.
7.What is the process for return or replacement of LM2574M-15/NOPB?
All LM2574M-15/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2574M-15/NOPB, 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-15/NOPB part is unused and in its original packaging.
Return procedure for LM2574M-15/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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