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Texas Instruments LM2671M-12
- Part No.:
- LM2671M-12
- Manufacturer:
- Texas Instruments
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM2671M-12.pdf
- Description:
- IC REG BUCK 12V 500MA 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,395
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Product details
Overview
LM2671M-12 from National Semiconductor is a monolithic 500mA step-down (buck) DC-DC voltage regulator in SO-8 package, featuring a fixed 12V output, 260 kHz fixed-frequency switching, 0.25Ω DMOS output switch, and ±1.5% output voltage tolerance over line and load. It delivers >94% efficiency at 24V input/500mA load and supports soft-start, frequency synchronization, and TTL-compatible shutdown for industrial power conversion.
For engineers reviewing the LM2671M-12 datasheet, LM2671M-12 pinout, LM2671M-12 application, or LM2671M-12 equivalent, key selection considerations include input voltage range (8–40V), thermal resistance (105°C/W), standby current (50 μA), current limit (0.8 A typical), and compatibility with standard off-the-shelf inductors and Schottky diodes.
Technical Context
The LM2671M-12 integrates a high-side DMOS switch, internal oscillator, soft-start circuit, and feedback comparator in a single SO-8 IC. Its 260 kHz fixed-frequency operation enables predictable EMI filtering and reduces external component size versus lower-frequency buck regulators.
It uses internal frequency compensation (Patents 5,382,918 and 5,514,947) and requires only five external components: input capacitor, output capacitor, catch diode, inductor, and boost capacitor. The device implements cycle-by-cycle current limiting and thermal shutdown for fault protection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 12 V, guaranteed 11.82–12.36 V over full operating temperature and load (20 mA to 500 mA) |
| Max Output Current | 500 mA continuous - sufficient for powering logic rails, analog subsystems, or intermediate bus stages |
| Input Voltage Range | 8 V to 40 V - supports wide-input industrial, telecom, and automotive auxiliary supplies |
| Switching Frequency | 260 kHz (±15 kHz) - enables use of compact 47–100 μH inductors and low-ESR tantalum output capacitors |
| Efficiency | 94% typical at VIN = 24 V, IOUT = 500 mA - minimizes board-level heat dissipation; copper traces serve as sole heatsink |
| Quiescent Current | 2.5 mA typical - low operating bias enables stable regulation without excessive no-load power loss |
| Standby Current | 50 μA typical during shutdown - supports low-power system sleep modes |
| Switch RDS(on) | 0.25 Ω typical - limits conduction loss and improves light-load efficiency vs. higher-RDS(on) alternatives |
Pinout & Package
LM2671M-12 is housed in an 8-pin SOIC (SO-8) surface-mount package per NSC drawing MO8A/N08E, with exposed pad not electrically connected. Thermal resistance θJA = 105°C/W with ~1 in² PCB copper.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VIN) | Input Supply | Primary DC input (8–40 V); bypassed externally with ≥22 μF tantalum capacitor |
| 2 (GND) | Power Ground | Common return for input/output paths and internal control circuitry; tied to PCB ground plane |
| 3 (SYNC) | Frequency Sync Input | Accepts external clock (up to 400 kHz) to synchronize switching; enables multi-regulator noise reduction |
| 4 (SW) | Switch Node | Drives external inductor; connects to cathode of catch diode and inductor's switched side |
| 5 (FB) | Feedback Input | Not used in fixed-output LM2671M-12; internally connected to 12 V reference; must be left unconnected |
| 6 (ON/OFF) | Shutdown Control | TTL-compatible enable pin; <2.0 V disables regulator (50 μA standby); >2.0 V enables operation |
| 7 (BOOST) | Bootstrap Capacitor Terminal | Connects to 0.01 μF ceramic capacitor between SW and BOOST to drive high-side switch gate fully |
| 8 (VOUT) | Regulated Output | Delivers regulated 12 V; filtered by ≥47 μF output capacitor with ≤0.1 Ω ESR |
Key Features
| Feature | Design Value |
|---|---|
| Patented Internal Compensation | Eliminates need for external compensation network - simplifies design and improves stability across input/load variations |
| Soft-Start Function | Controlled startup via external capacitor on SS pin - prevents inrush current and output overshoot during power-up |
| Current Limit & Thermal Shutdown | 0.8 A typical current limit + 150°C junction thermal cutoff - protects against short-circuit and overload faults without external sensing |
| Frequency Synchronization | SYNC pin accepts external clock up to 400 kHz - enables noise-sensitive multi-rail systems to avoid beat frequencies |
| Low Standby Quiescent Current | 50 μA typical in shutdown - supports battery-backed or energy-harvesting applications requiring ultra-low idle power |
| Wide Input Voltage Range | 8 V to 40 V operation - accommodates unregulated 12 V, 24 V, and 36 V industrial buses without pre-regulation |
Applications
| Industrial PLC Power Supply | Telecom Line Card Bias |
|---|---|
|
Use Scenario: Providing isolated 12 V rail for microcontroller, I/O drivers, and analog front-end in programmable logic controllers. IC Role / Device Role / Timing Role: Primary non-isolated buck converter delivering stable 12 V from 24 V backplane supply. Use Value: 94% efficiency minimizes thermal stress in enclosed cabinets; 500 mA output supports multiple downstream LDOs and sensors. |
Use Scenario: Generating clean 12 V bias for op-amps, ADCs, and interface transceivers on telecom line cards. IC Role / Device Role / Timing Role: Intermediate step-down regulator feeding low-noise linear regulators and precision analog circuits. Use Value: Fixed 12 V output eliminates resistor divider errors; 260 kHz switching allows small LC filter footprint near sensitive analog sections. |
| Automotive Body Control Module | Test Equipment Auxiliary Rail |
|
Use Scenario: Converting 12 V vehicle battery (transient-ruggedized to 40 V) to regulated 12 V for MCU and CAN transceiver power. IC Role / Device Role / Timing Role: Main DC-DC stage handling load dump and cold-crank conditions with integrated protection. Use Value: 40 V absolute max input and thermal shutdown ensure reliability during automotive load dump events; SO-8 package suits automated assembly. |
Use Scenario: Supplying stable 12 V to DUT interfaces, signal generators, or calibration circuitry in benchtop test equipment. IC Role / Device Role / Timing Role: Compact, self-contained buck regulator enabling modular, field-replaceable power modules. Use Value: Requires only 5 external parts and supports sync to system clock - simplifies compliance testing and reduces BOM count. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2672M-12 | Pin-compatible upgrade with improved efficiency (96% typ), lower quiescent current (1.5 mA), and enhanced thermal performance (θJA = 95°C/W). | Same SO-8 footprint and 12 V fixed output; better suited for thermally constrained or high-efficiency designs. | Select LM2672M-12 when upgrading legacy LM2671M-12 designs for higher efficiency or lower thermal rise. |
| TPS54318RTER | 3.5–28 V input, 12 V fixed output, 3 A capability, 570 kHz switching, integrated MOSFETs, and enable/sync pins - not pin-compatible. | Higher current and input flexibility; requires PCB redesign but supports tighter transient response and smaller magnetics. | Choose TPS54318RTER for new designs needing >500 mA or wider input range, accepting layout change. |
Compared with LM2671M-12, LM2672M-12 offers measurable thermal and efficiency gains in identical SO-8 layouts, while TPS54318RTER trades pin compatibility for higher integration and current capability - making it suitable only for greenfield designs prioritizing density and scalability.
Availability
LM2671M-12 is available at Aetrix Electronics and suitable for industrial automation, telecom infrastructure, and automotive body electronics requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LM2671M-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
National Semiconductor was a U.S.-based semiconductor company specializing in power management, data conversion, and interface ICs before its acquisition by Texas Instruments in 2011. Its SIMPLE SWITCHER® portfolio defined industry standards for ease-of-use in DC-DC conversion.
The LM2671 series was designed specifically for cost-sensitive, high-efficiency buck conversion in industrial and embedded systems where minimal external components, robust protection, and fixed-output simplicity were critical requirements.
FAQ
What is the maximum input voltage rating for LM2671M-12?
The absolute maximum input voltage for LM2671M-12 is 45 V, but the recommended operating range is 8 V to 40 V. Exceeding 40 V continuously risks exceeding safe operating area limits, especially under high ambient temperatures. The device includes internal protection, but sustained operation above 40 V is not specified or guaranteed per the April 2007 datasheet.
Does LM2671M-12 require an external feedback resistor network?
No, LM2671M-12 does not require an external feedback resistor network. As a fixed-output variant, its feedback node (Pin 5) is internally connected to the 12 V reference and must remain unconnected in circuit. Only adjustable versions (e.g., LM2671M-ADJ) use external resistors to set VOUT.
Can LM2671M-12 be synchronized to an external clock?
Yes, LM2671M-12 supports external frequency synchronization via Pin 3 (SYNC). Applying a square wave with ≥3 V peak-to-peak amplitude and frequency up to 400 kHz synchronizes the internal 260 kHz oscillator, reducing beat frequencies in multi-rail systems and enabling EMI optimization.
What is the thermal resistance (θJA) of LM2671M-12 in SO-8 package?
The junction-to-ambient thermal resistance (θJA) for LM2671M-12 in SO-8 package is 105°C/W, measured with approximately 1 in² of PCB copper surrounding the leads. Adding thermal vias or increasing copper area lowers this value, improving power handling capability without heatsinks.
Is LM2671M-12 RoHS compliant?
LM2671M-12 was introduced prior to mandatory RoHS enforcement and is not inherently RoHS-compliant in its original manufacturing release. However, National Semiconductor offered lead-free variants (e.g., LM2671M-12/NOPB) meeting RoHS Directive 2002/95/EC. Confirm compliance status using the specific date code and packaging marking (e.g., "2671M-12" vs. "2671M-12/NOPB") on the reel label or datasheet revision.
LM2671M-12 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 6.5V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 12V
- Voltage - Output (Max):
- -
- Current - Output:
- 500mA
- Frequency - Switching:
- 260kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
LM2671M-12 FAQ
1.How can I place an order for LM2671M-12 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2671M-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 LM2671M-12 reliable?
The price and inventory of LM2671M-12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2671M-12 is usually 5 days.
3.What payment methods are accepted for LM2671M-12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2671M-12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2671M-12?
LM2671M-12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2671M-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 LM2671M-12?
For technical support, including LM2671M-12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2671M-12 requirements.
6.How does Aetrix verify that LM2671M-12 is sourced from the original manufacturer or authorized distributors?
All LM2671M-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 LM2671M-12 meets industry standards.
7.What is the process for return or replacement of LM2671M-12?
All LM2671M-12 units undergo pre-shipment inspection (PSI). If there is an issue with LM2671M-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 LM2671M-12 part is unused and in its original packaging.
Return procedure for LM2671M-12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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