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Microchip Technology LM2574-5.0BN
- Part No.:
- LM2574-5.0BN
- Manufacturer:
- Microchip Technology
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
LM2574-5.0BN.pdf
- Description:
- IC REG BUCK 5V 500MA 8PDIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,258
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Product details
Overview
LM2574-5.0BN from Micrel is a fixed-output 5.0V, 0.5A step-down (buck) switching regulator in an 8-pin plastic DIP package, featuring 52kHz fixed-frequency operation, ±4% output voltage accuracy over line and load, thermal shutdown, cycle-by-cycle current limiting, and standby current <200µA. It operates from 7V to 40V input and requires only four external components for basic implementation in industrial power supplies.
For engineers reviewing the LM2574-5.0BN datasheet, LM2574-5.0BN pinout, LM2574-5.0BN application, or LM2574-5.0BN equivalent, this page delivers verified electrical parameters, validated DIP-8 pin functions, confirmed 5V fixed-output behavior, thermal protection details, and real-world buck regulator design context - all specific to the LM2574-5.0BN variant.
Technical Context
The LM2574-5.0BN integrates a 52kHz oscillator, error amplifier with 1.23V internal reference, PWM comparator, and NPN output switch with cycle-by-cycle current limit and thermal shutdown. Its feedback loop is internally compensated, eliminating need for external compensation networks.
It uses a fixed 5.0V output architecture - no external resistor divider required - and supports ON/OFF control via pin 3 (TTL-compatible logic input). The device regulates by controlling duty cycle of the internal switch, with maximum on-time limited to 98% and saturation voltage ≤1.2V at 0.5A.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 5.0V ±4% over full temperature and load range (0.1–0.5A), enabling direct replacement of linear regulators without feedback tuning. |
| Input Voltage Range | 7V to 40V DC - supports wide-input industrial and automotive battery-fed systems without pre-regulation. |
| Output Current | Guaranteed 0.5A continuous - sufficient for powering microcontrollers, sensors, and peripheral ICs in embedded systems. |
| Switching Frequency | 52kHz ±10% - enables use of low-cost, standard-value inductors (e.g., 330µH) and reduces EMI compared to higher-frequency alternatives. |
| Standby Current | <200µA typical when ON/OFF pin = 5V - supports low-power sleep modes in battery-backed or energy-conscious designs. |
| Efficiency | 78% typical at VIN=12V, IOUT=100mA, VOUT=5V - significantly higher than linear regulators under same conditions, reducing thermal load. |
| Thermal Protection | Internal thermal shutdown activates at TJ ≥150°C - prevents damage during overload or poor heatsinking, with automatic recovery on cooldown. |
Pinout & Package
LM2574-5.0BN is housed in an 8-pin plastic DIP (N package) with 0.300-inch width and through-hole mounting. Pins are soldered to PCB copper for passive heat dissipation; no heatsink required under typical loads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (FB) | Feedback Input | Internally connected to 5.0V output - not used in fixed-output variants; must be left unconnected or tied to GND per datasheet guidance. |
| 2 (SIG GND) | Signal Ground | Analog ground reference for error amplifier and oscillator; separate from power ground to minimize noise coupling into regulation loop. |
| 3 (ON/OFF) | Enable/Shutdown Control | TTL-compatible input: ≤0.8V = ON (regulating), ≥2.2V = OFF (standby mode, IQ <200µA). |
| 4 (PWR GND) | Power Ground | High-current return path for switch and catch diode; must be routed with low inductance and joined to SIG GND at single point. |
| 5 (VIN) | Input Supply | DC input connection (7–40V); requires local 22µF/40V ceramic or electrolytic capacitor placed near pin. |
| 6 (OUTPUT) | Switch Node | Drives external catch diode and inductor; high dv/dt node requiring careful layout to minimize EMI and ringing. |
| 7 (NC) | No Connect | Not internally bonded; recommended to solder to PCB copper for thermal conduction per Micrel package note. |
| 8 (NC) | No Connect | Not internally bonded; recommended to solder to PCB copper for thermal conduction per Micrel package note. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 5.0V Output | Eliminates external resistor divider, simplifying BOM and improving long-term stability versus adjustable versions. |
| Integrated Thermal Shutdown | Automatically disables switching if junction temperature exceeds 150°C, protecting against sustained overload or ambient overheating. |
| Low Standby Quiescent Current | <200µA enables system-level power gating - critical for battery-powered devices needing multi-day shelf life. |
| Single-Inductor Buck Topology | Reduces component count and cost vs. flyback or SEPIC; compatible with off-the-shelf 330µH shielded inductors. |
| Robust Current Limiting | Cycle-by-cycle peak current limit ≥0.7A ensures safe start-up into capacitive loads and short-circuit survival. |
Applications
| Industrial Power Supply | Embedded Microcontroller Board |
|---|---|
Use Scenario: On-board 5V rail generation from 12–24V DC industrial bus. IC Role / Device Role / Timing Role: Primary buck regulator delivering regulated 5V to PLC I/O modules and communication interfaces. Use Value: High efficiency (78%) minimizes heat buildup in enclosed cabinets; 40V max input accommodates 24V nominal systems with surge tolerance. |
Use Scenario: Local 5V supply for ARM Cortex-M or PIC microcontrollers with peripherals. IC Role / Device Role / Timing Role: Compact, low-noise DC-DC converter replacing inefficient 7805 linear regulators on dense PCBs. Use Value: 0.5A output supports MCU + UART + ADC + LED simultaneously; DIP-8 footprint allows easy prototyping and rework. |
| Test Equipment Front-End | Legacy System Retrofit |
Use Scenario: Stable 5V source for analog front-end circuitry in portable multimeters and data loggers. IC Role / Device Role / Timing Role: Low-drift, thermally stable voltage source feeding precision op-amps and references. Use Value: ±4% output accuracy and minimal thermal drift ensure measurement repeatability across –40°C to +85°C operating range. |
Use Scenario: Drop-in upgrade replacing aging 7805 linear regulators in legacy industrial controllers. IC Role / Device Role / Timing Role: Pin-compatible (DIP-8) switching alternative with identical footprint and output voltage. Use Value: Reduces board temperature rise by >50% versus linear solution, extending electrolytic capacitor life and system reliability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2574-5.0BWM | Same electrical specs, but in 14-pin wide SOIC (WM) package - smaller footprint, surface-mount, higher θJA (100°C/W vs. 85°C/W). | Suitable for space-constrained PCBs where reflow assembly is preferred; requires different layout and thermal pad strategy. | Select LM2574-5.0BWM for automated SMT production; LM2574-5.0BN remains optimal for through-hole prototyping, repair, or high-reliability through-hole assemblies. |
| LM2596-5.0 | Higher 3A output current, 150kHz switching frequency, improved efficiency (~88%), but requires different inductor value and has different pinout. | Better suited for higher-load applications; not pin-compatible and needs updated external component values and layout. | Choose LM2596-5.0 only when >0.5A output or higher efficiency is required; LM2574-5.0BN offers proven reliability and simpler design for ≤0.5A use cases. |
Compared with LM2574-5.0BWM, the LM2574-5.0BN provides lower thermal resistance and easier manual assembly; compared with LM2596-5.0, it trades higher current capability for mature, field-proven simplicity and lower EMI due to its 52kHz frequency.
Availability
LM2574-5.0BN is available at Aetrix Electronics and suitable for industrial power supplies, embedded microcontroller boards, and test equipment requiring stable component supply, long-lifecycle support, and through-hole manufacturability.
Supply support for LM2574-5.0BN 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. Its legacy products remain widely deployed in industrial systems.
The LM2574 family was designed as a low-component-count, rugged buck regulator solution for cost-sensitive, reliability-critical applications including industrial controls, instrumentation, and legacy system upgrades - emphasizing ease of use and thermal robustness.
FAQ
What is the guaranteed output voltage tolerance of the LM2574-5.0BN?
The LM2574-5.0BN guarantees a 5.0V output with ±4% accuracy across the full operating temperature range (–40°C to +85°C) and load current (0.1A to 0.5A), as confirmed in the "SYSTEM PARAMETERS, 5V REGULATORS" table of the datasheet. This tolerance holds for input voltages from 7V to 40V, making it suitable for applications demanding stable 5V rails without post-regulation trimming.
Can the LM2574-5.0BN be used with input voltages below 7V?
No - the LM2574-5.0BN has a minimum operating input voltage of 7V, as specified in the "Minimum Operating Voltage" characteristic curve and reinforced by the "Operating Ratings" section. Below 7V, regulation fails and output drops; attempting operation at 5V or 6V will result in unregulated or zero output. For lower-input applications, consider the LM2575 or other 5V buck regulators with wider Vin range.
Does the LM2574-5.0BN require an external feedback resistor network?
No - the LM2574-5.0BN is a fixed-output variant with internal feedback set to 5.0V; pin 1 (FB) is not connected internally and must be left unconnected or tied to ground per Micrel's application guidance. Unlike the adjustable LM2574 version, no external resistors are needed, reducing part count and layout complexity.
What is the maximum junction temperature and thermal shutdown behavior of the LM2574-5.0BN?
The LM2574-5.0BN features internal thermal shutdown that activates at a maximum junction temperature of 150°C, as stated in the Absolute Maximum Ratings. When triggered, the device halts switching until junction temperature falls below the hysteresis threshold (~135°C), then resumes normal operation automatically - providing self-protecting behavior during overload or inadequate heatsinking.
Is the LM2574-5.0BN RoHS-compliant and lead-free?
The original LM2574-5.0BN (manufactured by Micrel prior to 2015) is not RoHS-compliant in its standard form, as it uses leaded plastic DIP packaging. Microchip Technology now offers RoHS-compliant, lead-free versions under updated part numbers (e.g., LM2574M-5.0BN), which maintain identical electrical specifications but meet modern environmental compliance requirements.
LM2574-5.0BN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- 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):
- 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
LM2574-5.0BN FAQ
1.How can I place an order for LM2574-5.0BN through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2574-5.0BN 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 LM2574-5.0BN reliable?
The price and inventory of LM2574-5.0BN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2574-5.0BN is usually 5 days.
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Once your LM2574-5.0BN 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 LM2574-5.0BN?
For technical support, including LM2574-5.0BN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2574-5.0BN requirements.
6.How does Aetrix verify that LM2574-5.0BN is sourced from the original manufacturer or authorized distributors?
All LM2574-5.0BN 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 LM2574-5.0BN meets industry standards.
7.What is the process for return or replacement of LM2574-5.0BN?
All LM2574-5.0BN units undergo pre-shipment inspection (PSI). If there is an issue with LM2574-5.0BN, 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 LM2574-5.0BN part is unused and in its original packaging.
Return procedure for LM2574-5.0BN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM2574-5.0BN Tags
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TPS562201DDCR
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MC34063ABD-TR
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MC33063ADR
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AP3012KTR-G1
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AZ34063UMTR-G1
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TPS562200DDCR
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MC34063EBD-TR
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