My Inquiry
My Account
Texas Instruments LM2574N-12
- Part No.:
- LM2574N-12
- Manufacturer:
- Texas Instruments
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
LM2574N-12.pdf
- Description:
- IC REG BUCK 12V 500MA 8PDIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,888
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM2574N-12 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 12V output with ±4% tolerance over line and load, 52 kHz fixed-frequency operation, and thermal/current limiting protection. It replaces linear regulators in mid-power DC-DC conversion for industrial power supplies and embedded systems requiring stable 12V rail generation from higher input voltages up to 40V.
For engineers reviewing the LM2574N-12 datasheet, LM2574N-12 pinout, LM2574N-12 application, or LM2574N-12 equivalent, this device serves as a cost-optimized, low-component-count buck regulator where efficiency >88%, minimal external parts (4 components), and robust fault protection are critical selection criteria.
Technical Context
The LM2574N-12 integrates a PWM controller, power switch, oscillator, and internal frequency compensation in a single IC. Its 52 kHz fixed-frequency architecture enables predictable EMI filtering and simplifies inductor selection using standardized 330 µH values optimized for 12V output at 0.5A load.
It operates in continuous conduction mode across its specified input range (15–40V) and load range (0.1–0.5A), with cycle-by-cycle current limiting (1.0A peak), thermal shutdown, and TTL-compatible ON/OFF control enabling reliable start-up, sequencing, and standby modes with 50 µA quiescent current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 12V ±4% over 15–40V input and 0.1–0.5A load - ensures stable rail for logic, analog, and interface ICs without external feedback resistors. |
| Max Output Current | 0.5A continuous - supports moderate-power subsystems like microcontroller cores, sensors, and peripheral drivers. |
| Input Voltage Range | 40V max (LM2574 series) - accommodates unregulated 24V or 36V industrial bus inputs with margin. |
| Switching Frequency | 52 kHz fixed - enables use of low-cost, high-saturation-current inductors (e.g., Pulse PE-52627) and reduces EMI filter complexity vs. MHz-range converters. |
| Efficiency | 88% at VIN = 15V, IOUT = 0.5A - minimizes thermal stress and eliminates need for heatsinks beyond PCB copper area. |
| Quiescent Current | 5 mA typical operating / 50 µA standby - supports low-power sleep modes when ON/OFF pin is pulled high. |
| Protection Features | Cycle-by-cycle current limit (1.0A peak), thermal shutdown, and output short-circuit recovery - ensures self-recovery under overload without external circuitry. |
Pinout & Package
Package: 8-pin plastic DIP (NS package N08A), through-hole mount, with Pin 5 internally connected to substrate for thermal conduction - requires soldering to PCB copper for optimal heat transfer.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VIN) | Input Supply | Accepts 15–40V unregulated DC; bypassed externally with ≥22 µF electrolytic capacitor near pin. |
| 2 (GND) | Power Ground | Common return for input capacitor, output capacitor, and catch diode cathode; must be low-inductance connection. |
| 3 (OUT) | Switch Node | Drives external catch diode anode and inductor; carries pulsed 0.5A current with 0.9V saturation drop. |
| 4 (GND) | Power Ground | Second ground pin for improved thermal and current path separation; tied to Pin 2 on PCB. |
| 5 (NC) | No Internal Connection | Thermally connected to die substrate; must be soldered to large copper pour for junction-to-ambient θJA = 72°C/W. |
| 6 (ON/OFF) | Enable Control | TTL-compatible shutdown: <1.2V = ON, >2.2V = OFF; draws ≤30 µA in shutdown mode. |
| 7 (FEEDBACK) | Not Used | Internally tied to 12V reference; left unconnected for fixed-output versions. |
| 8 (GND) | Power Ground | Third ground pin; all three GND pins (2,4,8) must be joined with minimal trace length. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 12V output | Eliminates external resistor divider, reducing BOM count and layout sensitivity while guaranteeing ±4% regulation accuracy. |
| 52 kHz oscillator | Enables use of standard off-the-shelf 330 µH inductors (e.g., Renco RL-1284-330) without custom magnetics or high-frequency EMI mitigation. |
| Internal frequency compensation | Removes need for external compensation network, allowing stable operation with only 4 external components: input cap, output cap, inductor, catch diode. |
| TTL shutdown | Supports system-level power sequencing and low-power standby with 50 µA quiescent current - ideal for battery-backed or energy-conscious designs. |
| Thermal + current protection | Self-protecting under sustained overload or ambient temperature rise to 125°C junction, preventing catastrophic failure without external sensing. |
Applications
| Industrial Power Supplies | Embedded Controller Boards |
|---|---|
Use Scenario: Generating 12V from 24V industrial bus for PLC I/O modules and sensor signal conditioning circuits. IC Role / Device Role / Timing Role: Primary step-down regulator providing isolated, efficient, and thermally robust 12V rail. Use Value: Delivers 0.5A at 88% efficiency with no heatsink required, reducing board space and thermal management complexity. | Use Scenario: On-card DC-DC conversion for microcontroller-based motor drives requiring clean 12V supply for gate drivers and logic. IC Role / Device Role / Timing Role: Local buck regulator replacing inefficient linear regulators to minimize power loss and board heating. Use Value: Fixed 12V output ensures consistent timing margins for gate drivers; 52 kHz switching avoids audible noise and simplifies filtering. |
| Test & Measurement Equipment | Legacy System Upgrades |
Use Scenario: Replacing aging linear regulators in bench power supplies to improve thermal performance and reduce cooling requirements. IC Role / Device Role / Timing Role: High-efficiency pre-regulator feeding downstream LDOs for low-noise analog rails. Use Value: 88% efficiency cuts dissipation by >70% vs. linear solution, extending equipment lifetime and enabling fanless operation. | Use Scenario: Retrofitting obsolete 7812 linear regulators in legacy instrumentation with modern switching efficiency and reliability. IC Role / Device Role / Timing Role: Drop-in compatible buck replacement maintaining same 12V output and footprint constraints. Use Value: Maintains identical input/output pin locations (DIP-8), requires only addition of inductor, diode, and capacitors - no PCB redesign needed. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2574M-12 | Same electrical specs, but in 14-pin SOIC (M14B) surface-mount package - θJA = 78°C/W vs. 72°C/W for N-package. | Suitable for automated SMT assembly; requires different PCB footprint and reflow profile. | Select when board space is constrained and SMT manufacturing is preferred over through-hole. |
| LM2596-12 | Higher 3A output current, 150 kHz switching, adjustable feedback - wider VIN range (4.5–40V), lower dropout, but requires external compensation. | Better suited for higher-current or dynamically adjustable outputs; not pin-compatible. | Choose when future scalability to >0.5A or programmable output is anticipated - otherwise LM2574N-12 offers simpler design and lower cost. |
Compared with LM2574M-12, the LM2574N-12 provides superior thermal performance in through-hole applications due to lower θJA (72°C/W) and direct substrate thermal coupling via Pin 5; compared with LM2596-12, it trades higher current capability for reduced component count, fixed-output simplicity, and proven reliability in legacy industrial designs.
Availability
LM2574N-12 is available at Aetrix Electronics and suitable for industrial power supplies, embedded controller boards, and test equipment requiring stable component supply with long-term lifecycle support and traceable sourcing.
Supply support for LM2574N-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, datasheets, and legacy product continuity for the SIMPLE SWITCHER™ portfolio.
The LM2574N-12 belongs to TI's SIMPLE SWITCHER™ family of integrated buck regulators, designed specifically for cost-sensitive, medium-power DC-DC conversion in industrial, automotive, and embedded applications where ease of design and reliability outweigh ultra-high efficiency or miniaturization.
FAQ
What is the maximum input voltage rating for the LM2574N-12?
The LM2574N-12 has an absolute maximum input voltage of 45V and a recommended maximum operating input voltage of 40V. Exceeding 40V risks violating the guaranteed electrical specifications, particularly output voltage accuracy and efficiency. The LM2574HV-12 variant supports up to 60V operating input, but the LM2574N-12 is strictly rated for ≤40V input in normal operation.
Does the LM2574N-12 require an external feedback resistor network?
No, the LM2574N-12 does not require external feedback resistors. It is a fixed-output version with internal 12V reference and feedback divider. Pin 7 (FEEDBACK) is not connected internally for fixed-output variants and must remain unconnected in the LM2574N-12 design.
What is the minimum load current required for stable operation of the LM2574N-12?
The LM2574N-12 is specified for stable operation down to 0.1A load current under nominal conditions (15–40V input). Below 0.1A, it may enter discontinuous conduction mode - which is fully supported and does not affect regulation, though output ripple increases slightly. No minimum load is required for functionality.
Can the LM2574N-12 be used in a positive-to-negative buck-boost configuration?
Yes, the LM2574N-12 can be configured as a positive-to-negative inverting buck-boost converter per National Semiconductor Application Note AN-1182. In that topology, the IC regulates the magnitude of the negative output voltage (e.g., −12V), with Pin 3 (OUT) becoming the inverting switch node and Pin 2 (GND) serving as the negative output reference. Component selection and layout differ significantly from standard buck operation.
What is the thermal resistance (θJA) of the LM2574N-12 in typical PCB layout?
For the LM2574N-12 in an 8-pin DIP package (N08A), θJA is 92°C/W with ~1 in² of 1 oz. copper and 72°C/W with ~4 in² of 1 oz. copper surrounding the leads. Pin 5 is thermally connected to the die substrate and must be soldered to the PCB copper pour to achieve the lower value - this is essential for sustaining 0.5A output at elevated ambient temperatures.
LM2574N-12 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):
- 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
LM2574N-12 FAQ
1.How can I place an order for LM2574N-12 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2574N-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 LM2574N-12 reliable?
The price and inventory of LM2574N-12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2574N-12 is usually 5 days.
3.What payment methods are accepted for LM2574N-12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2574N-12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2574N-12?
LM2574N-12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2574N-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 LM2574N-12?
For technical support, including LM2574N-12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2574N-12 requirements.
6.How does Aetrix verify that LM2574N-12 is sourced from the original manufacturer or authorized distributors?
All LM2574N-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 LM2574N-12 meets industry standards.
7.What is the process for return or replacement of LM2574N-12?
All LM2574N-12 units undergo pre-shipment inspection (PSI). If there is an issue with LM2574N-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 LM2574N-12 part is unused and in its original packaging.
Return procedure for LM2574N-12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM2574N-12 Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
