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Microchip Technology LM2574-12YN
- Part No.:
- LM2574-12YN
- Manufacturer:
- Microchip Technology
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
LM2574-12YN.pdf
- Description:
- IC REG BUCK 12V 500MA 8PDIP
- Quantity:
- Payment:
- Shipping:
Inventory:155
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Product details
Overview
LM2574-12YN from Micrel, Inc. is a fixed-output 12V, 0.5A step-down (buck) switching regulator in an 8-pin plastic DIP package, featuring internal 52kHz oscillator (±10%), ±4% output voltage accuracy over line/load, thermal shutdown, and cycle-by-cycle current limiting. It delivers stable DC-DC conversion for industrial power supplies requiring minimal external components.
For engineers reviewing the LM2574-12YN datasheet, LM2574-12YN pinout, LM2574-12YN application, or LM2574-12YN equivalent, key selection criteria include input voltage range (up to 40V), guaranteed 0.5A output, standby current <200µA, fixed 12V output, and DIP-8 thermal performance without heatsink.
Technical Context
The LM2574-12YN integrates a 52kHz fixed-frequency oscillator, error amplifier with 1.23V internal reference, PWM comparator, and N-channel switch driver. Its architecture uses external diode, inductor, and capacitors to form a non-synchronous buck topology with duty cycle controlled by feedback regulation.
It operates across –40°C to +125°C junction temperature, supports ON/OFF control via logic-level pin (VIH ≥ 2.2V, VIL ≤ 1.2V), and provides built-in protection including thermal shutdown and peak current limit of 0.7–1.6A. Efficiency reaches up to 78% at VIN = 12V, IOUT = 100mA, VOUT = 12V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 12V ±4% over full line/load/temperature range - ensures stable rail for downstream logic or analog circuitry without trimming. |
| Max Output Current | 0.5A continuous - sufficient for powering microcontrollers, sensors, or small peripherals without derating at 25°C ambient. |
| Input Voltage Range | 4.75V to 40V - supports wide-input industrial or automotive-derived supplies, including unregulated 24V bus inputs. |
| Oscillator Frequency | 52kHz ±10% - enables use of low-cost, standard-value inductors (e.g., 330µH) and simplifies EMI filtering design. |
| Standby Quiescent Current | <200µA typical - allows low-power sleep mode in battery-backed or energy-conscious systems. |
| Thermal Resistance θJA | 85°C/W (DIP-8 package) - permits full 0.5A operation with PCB copper pour alone; no heatsink required under typical conditions. |
| Current Limit Threshold | 0.7–1.6A peak - provides robust short-circuit protection while allowing inrush current margin for capacitive loads. |
Pinout & Package
LM2574-12YN is housed in an 8-pin plastic DIP (N) package with 0.3" width and through-hole mounting. Thermal performance relies on soldering all pins to PCB copper for heat conduction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 FB | Feedback Input | Not connected in fixed 12V version; internally tied to 12V output divider - eliminates external resistor network. |
| 2 SIG GND | Signal Ground | Reference node for internal error amplifier and oscillator - must be routed separately from power ground to minimize noise coupling. |
| 3 ON/OFF | Enable/Shutdown Control | Logic-high (>2.2V) enables regulation; logic-low (<1.2V) disables output and reduces quiescent current to <200µA. |
| 4 PWR GND | Power Ground | Return path for switch current and output capacitor - connects to high-current ground plane to reduce voltage spikes. |
| 5 VIN | Input Supply | Accepts 4.75–40V DC - requires local 22µF/40V input capacitor to suppress ripple and supply transient current. |
| 6 OUTPUT | Switch Node | Drives external catch diode and inductor - high dv/dt node; layout critical to minimize EMI and ringing. |
| 7 NC | No Connect | Internally unused - must remain unconnected; no routing or grounding recommended. |
| 8 NC | No Connect | Internally unused - must remain unconnected; no routing or grounding recommended. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 12V output | Eliminates external feedback resistors - reduces BOM count, layout area, and calibration risk in production. |
| Internal 52kHz oscillator | Enables predictable switching frequency for EMI compliance and consistent inductor sizing across designs. |
| Cycle-by-cycle current limiting | Prevents MOSFET failure during output shorts or startup surges - no external sensing needed. |
| Thermal shutdown | Automatically disables regulator at TJ ≥ 150°C - protects device and system during overload or poor ventilation. |
| Low standby current | Reduces system-level power draw in OFF state - critical for battery-powered or always-on monitoring applications. |
Applications
| Industrial Power Supplies | Embedded Controller Rails |
|---|---|
Use Scenario: Converting unregulated 24V DC from factory PLC backplanes into clean 12V for field I/O modules. IC Role / Device Role / Timing Role: Primary buck regulator providing isolated, regulated 12V rail with fault protection. Use Value: Delivers 0.5A at ±4% accuracy without heatsink, reducing board space and cost versus linear regulators. |
Use Scenario: Powering ARM Cortex-M4 microcontrollers and associated peripherals in edge gateways. IC Role / Device Role / Timing Role: Main DC-DC converter supplying core logic voltage with ON/OFF control synchronized to system sleep states. Use Value: Standby current <200µA extends battery life during deep-sleep modes while maintaining fast wake-up capability. |
| On-Card Switching Regulators | Efficient Pre-regulators |
Use Scenario: Local 12V generation on dense PCBs where space prohibits external DC-DC modules. IC Role / Device Role / Timing Role: Compact, through-hole buck solution minimizing component footprint and assembly complexity. Use Value: Requires only four external parts (diode, inductor, two capacitors) - accelerates design and improves yield. |
Use Scenario: Reducing 36V input to 15V before feeding a low-noise LDO for analog sensor front-ends. IC Role / Device Role / Timing Role: High-efficiency pre-regulator lowering power dissipation and thermal load on downstream LDO. Use Value: Achieves ~75% efficiency at 0.5A, cutting heat generation by >60% versus linear pre-regulation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2574H-12CN | Same 12V fixed output, but rated for –40°C to +125°C junction range and TO-220 package - higher thermal mass, different mounting. | Preferred for high-temperature environments (>85°C ambient) or when surface-mount is not feasible. | Select LM2574H-12CN if operating junction exceeds 125°C or mechanical mounting requires TO-220 flange. |
| LM2596-12 | Higher 3A output rating, 150kHz switching frequency, and improved line/load regulation (±2%) - requires different inductor/capacitor values. | Better suited for higher-current or tighter-regulation requirements; not drop-in due to frequency and layout changes. | Choose LM2596-12 only when >0.5A output or tighter voltage tolerance is mandatory - redesign of LC filter required. |
Compared with LM2574-12YN, LM2574H-12CN offers extended temperature capability in a thermally superior package, while LM2596-12 provides higher current and precision at the cost of layout rework and increased component count.
Availability
LM2574-12YN is available at Aetrix Electronics and suitable for industrial power supplies, embedded controller rails, and on-card switching regulators requiring stable component supply, long-term lifecycle support, and RoHS-compliant through-hole packaging.
Supply support for LM2574-12YN 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
Micrel, Inc. was a U.S.-based semiconductor company specializing in analog, power management, and timing solutions before its acquisition by Microchip Technology in 2015.
The LM2574 product line was designed for cost-sensitive, medium-current DC-DC conversion in industrial, telecom, and embedded systems where simplicity, reliability, and minimal external components were prioritized.
FAQ
What is the maximum input voltage for the LM2574-12YN?
The LM2574-12YN supports a maximum continuous input voltage of 40V under operating conditions, with absolute maximum rating at 45V. Exceeding 40V may cause premature thermal shutdown or reduced reliability. The LM2574-12YN is commonly used with 24V industrial rails or rectified 17V AC inputs, staying well within safe margins.
Does the LM2574-12YN require an external feedback resistor network?
No, the LM2574-12YN does not require external feedback resistors. As a fixed-output variant, its internal voltage divider is factory-trimmed to deliver 12V ±4%. Pin 1 (FB) is internally connected and must remain unconnected in circuit - unlike the adjustable LM2574, the LM2574-12YN simplifies design by eliminating resistor selection and placement.
Can the LM2574-12YN be used in battery-powered applications?
Yes, the LM2574-12YN supports battery-powered applications via its ON/OFF pin (Pin 3), which reduces quiescent current to less than 200µA in standby mode. When paired with a lithium-thionyl chloride or alkaline primary cell, the LM2574-12YN enables multi-year operation in low-duty-cycle sensor nodes - confirmed by Micrel's typical characteristics data at TJ = 25°C and VIN = 12V.
What is the thermal performance of the LM2574-12YN in DIP-8 package?
The LM2574-12YN in 8-pin plastic DIP has a junction-to-ambient thermal resistance (θJA) of 85°C/W when mounted on a standard PCB with ~1 in² copper area. At 0.5A output and 24V input, power dissipation remains below 6W, resulting in ~510°C rise - well within the 150°C max junction limit when ambient is ≤75°C. No heatsink is required under these conditions.
Is the LM2574-12YN pin-compatible with other LM2574 fixed-output variants?
Yes, the LM2574-12YN shares identical pinout, package, and electrical interface with LM2574-3.3YN, LM2574-5.0YN, and LM2574-ADJYN. All use the same 8-pin DIP (N) footprint and functional pin assignments - enabling direct substitution in existing layouts when only output voltage differs, provided input/output capacitor ratings match the new voltage level.
LM2574-12YN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- -
- 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:
- Through Hole
- Supplier Device Package:
- 8-PDIP
LM2574-12YN FAQ
1.How can I place an order for LM2574-12YN through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2574-12YN 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 LM2574-12YN reliable?
The price and inventory of LM2574-12YN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2574-12YN is usually 5 days.
3.What payment methods are accepted for LM2574-12YN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2574-12YN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2574-12YN?
LM2574-12YN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2574-12YN 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 LM2574-12YN?
For technical support, including LM2574-12YN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2574-12YN requirements.
6.How does Aetrix verify that LM2574-12YN is sourced from the original manufacturer or authorized distributors?
All LM2574-12YN 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 LM2574-12YN meets industry standards.
7.What is the process for return or replacement of LM2574-12YN?
All LM2574-12YN units undergo pre-shipment inspection (PSI). If there is an issue with LM2574-12YN, 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 LM2574-12YN part is unused and in its original packaging.
Return procedure for LM2574-12YN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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