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Texas Instruments LM2671M-ADJ
- Part No.:
- LM2671M-ADJ
- Manufacturer:
- Texas Instruments
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM2671M-ADJ.pdf
- Description:
- IC REG BUCK ADJ 500MA 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,866
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Product details
Overview
LM2671M-ADJ from Texas Instruments is a monolithic step-down (buck) DC-DC switching regulator IC with integrated 0.25-Ω DMOS power switch, delivering up to 500 mA output current. It operates from 8 V to 40 V input, provides adjustable output from 1.21 V to 37 V, and achieves up to 96% efficiency in typical buck configurations for industrial power rails and embedded subsystems.
For engineers reviewing the LM2671M-ADJ datasheet, LM2671M-ADJ pinout, LM2671M-ADJ application, or LM2671M-ADJ equivalent, key selection criteria include its 260-kHz fixed-frequency oscillator, ±1.5% output voltage tolerance over line/load/temperature, TTL-compatible ON/OFF control, soft-start capability, and thermal/current-limit protection - all in an 8-pin SOIC package.
Technical Context
The LM2671M-ADJ implements a voltage-mode PWM controller with internal 260-kHz oscillator and patented frequency compensation. Its feedback loop uses a precision 1.21-V reference amplifier (VFB = 1.21 V ±1.5%) to regulate output via external resistor divider, enabling stable operation across 1.21–37 V range. The high-side DMOS switch features 0.25-Ω RDS(ON) at 25°C and supports duty cycles from 0% to 95%.
Functional modes include active regulation (ON/OFF ≥1.4 V), low-power shutdown (ON/OFF ≤0.8 V, ISTBY = 50 μA typ), and synchronized operation (SYNC pin accepts external clock >275 kHz). Protection includes cycle-by-cycle current limiting (ICL = 0.62–1.2 A), thermal shutdown, and under-voltage lockout on VIN.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output current | 500 mA guaranteed continuous load current without derating at TJ ≤125°C |
| Input voltage range | 6.5 V to 40 V - supports wide industrial input rails including 12 V, 24 V, and 36 V systems |
| Output voltage range | 1.21 V to 37 V - set by external resistor divider; VFB = 1.21 V ±1.5% ensures tight regulation |
| Switching frequency | 260 kHz fixed - enables use of compact, standard inductors (e.g., 22–68 µH) and reduces EMI filtering burden |
| Efficiency | Up to 96% - achieved via low RDS(ON) (0.25 Ω) DMOS switch and optimized gate drive (CB bootstrap) |
| Quiescent current | 3.6 mA typ in active mode; 50 μA typ in shutdown - minimizes standby power loss in battery-backed systems |
| Protection features | Thermal shutdown, cycle-by-cycle current limit, and soft-start - prevent inrush damage and ensure robust startup |
Pinout & Package
LM2671M-ADJ is housed in an 8-pin SOIC (D package), 4.90 mm × 3.91 mm body size, with exposed pad not present. Pin functions are validated per TI SNVS008L Rev L datasheet (June 2016).
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CB) | Bootstrap capacitor connection | Connects 100-nF ceramic capacitor to VSW to generate gate drive voltage >VIN for full enhancement of internal DMOS switch |
| 2 (SS) | Soft-start control | Capacitor-to-GND sets output voltage ramp time; floating disables soft-start - prevents inrush current during power-up |
| 3 (SYNC) | Frequency synchronization input | Accepts external TTL/CMOS clock >275 kHz to align switching frequency - enables EMI reduction and multi-rail phase control |
| 4 (FB) | Feedback sense input | High-impedance (85 nA bias) input referenced to 1.21 V - connects to resistor divider midpoint to program output voltage |
| 5 (ON/OFF) | Enable/disable control | TTL-compatible input: ≥1.4 V = ON, ≤0.8 V = OFF - draws only 50 μA in shutdown, enabling low-power system management |
| 6 (GND) | Power ground | Primary return path for input/output capacitors and internal circuitry - requires short, low-inductance PCB trace to minimize noise |
| 7 (VIN) | Input supply | Accepts 6.5–40 V DC - must be bypassed with local high-frequency capacitor (e.g., 22 µF tantalum) to suppress switching transients |
| 8 (VSW) | Switch node output | Drains internal DMOS switch - connects directly to inductor and Schottky diode cathode; high dv/dt node requiring careful layout |
Key Features
| Feature | Design Value |
|---|---|
| Integrated DMOS power switch | 0.25-Ω RDS(ON) at 25°C enables high-efficiency 500-mA buck conversion without external MOSFET |
| Adjustable output voltage | 1.21 V to 37 V range via two-resistor feedback divider - supports diverse rail requirements from logic to analog subsystems |
| Fixed 260-kHz switching | Enables predictable EMI spectrum and use of small, off-the-shelf inductors - eliminates need for external timing components |
| TTL-compatible enable | ON/OFF pin with 1.4 V threshold and 50 μA shutdown current - simplifies interface with microcontrollers and PMICs |
| Internal soft-start | Capacitor-programmable output ramp - prevents output overshoot and inductor saturation during startup |
| Comprehensive protection | Current limit, thermal shutdown, and undervoltage lockout - ensure reliable operation under fault conditions without external circuitry |
Applications
| Industrial Power Supply | Automotive Subsystem Rail |
|---|---|
|
Use Scenario: Generating stable 5 V or 12 V from a 24 V vehicle battery for infotainment MCU and CAN transceivers. IC Role / Device Role / Timing Role: Primary step-down regulator providing isolated, efficient DC-DC conversion with thermal protection in high-ambient environments. Use Value: Delivers 500 mA at >90% efficiency with no heatsink required - copper PCB traces serve as sole thermal path per TI thermal data. |
Use Scenario: Converting 12 V battery voltage to 3.3 V for automotive sensor signal conditioning and ADC reference. IC Role / Device Role / Timing Role: Adjustable-output buck converter configured for precise low-noise 3.3 V rail with ±1.5% regulation tolerance. Use Value: Tight VFB = 1.21 V ±1.5% and low 85 nA feedback bias current minimize divider error and load regulation drift. |
| Industrial PLC I/O Module | Embedded Communication Gateway |
|
Use Scenario: Powering isolated RS-485 transceivers and digital I/O drivers from a 24 V field bus in programmable logic controllers. IC Role / Device Role / Timing Role: High-input-voltage buck regulator supporting 8–40 V range with robust current limit (0.62–1.2 A) for transient overload immunity. Use Value: Cycle-by-cycle current limiting and thermal shutdown protect against sustained short-circuit faults in harsh industrial environments. |
Use Scenario: Providing clean 1.8 V or 2.5 V core voltage for ARM-based gateway processors in smart metering or edge IoT devices. IC Role / Device Role / Timing Role: Adjustable buck regulator with soft-start and SYNC input - enables controlled power sequencing and EMI-synchronized multi-rail designs. Use Value: External clock synchronization allows alignment of switching edges across multiple LM2671M-ADJ rails to reduce peak EMI amplitude. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2576HVS-ADJ | Higher 3-A output current, 52-kHz switching frequency, larger minimum external components | Better suited for high-current (>1 A), low-EMI applications where board space is less constrained | Select when higher output current or lower switching frequency is required; not pin-compatible |
| TPS54302DDCR | 3-A synchronous buck, 2.5–6 V input, integrated high/low-side FETs, 2-MHz switching | Optimized for low-input-voltage, high-density applications (e.g., 5 V input rails); lacks 40 V input capability | Choose for compact, high-frequency designs with <6 V input; LM2671M-ADJ remains preferred for 8–40 V industrial inputs |
Compared with LM2576HVS-ADJ and TPS54302DDCR, the LM2671M-ADJ uniquely balances 40 V max input, 500 mA output, 260 kHz fixed frequency, and SOIC-8 simplicity - making it optimal for cost-sensitive, medium-power industrial buck converters where wide VIN and proven reliability are critical.
Availability
LM2671M-ADJ is available at Aetrix Electronics and suitable for industrial PLCs, automotive sub-systems, embedded gateways, and test equipment requiring stable component supply with long-term lifecycle support.
Supply support for LM2671M-ADJ 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 is a global semiconductor leader specializing in analog, embedded processing, and power management technologies, with decades of expertise in high-reliability power conversion ICs.
The LM2671M-ADJ belongs to TI's SIMPLE SWITCHER® family - designed specifically for ease-of-use, minimal external component count, and robust performance in industrial and automotive DC-DC applications.
FAQ
What is the maximum input voltage rating for the LM2671M-ADJ?
The LM2671M-ADJ has an absolute maximum input voltage rating of 45 V, but its recommended operating range is 6.5 V to 40 V. Operation above 40 V risks exceeding safe junction temperature or violating SOIC package thermal limits. For sustained 40 V operation, ensure adequate PCB copper area per TI's thermal guidelines in SNVS008L.
How do I configure the LM2671M-ADJ for a 3.3 V output?
To configure the LM2671M-ADJ for 3.3 V output, connect a resistor divider between VOUT and GND such that the FB pin sees 1.21 V. Using R1 (top) and R2 (bottom), set R1 = R2 × (3.3 V / 1.21 V − 1). For example, with R2 = 10 kΩ, R1 ≈ 17.3 kΩ. Ensure both resistors are 1% tolerance metal film for ±1.5% output accuracy.
Does the LM2671M-ADJ require an external catch diode?
Yes, the LM2671M-ADJ requires an external Schottky diode connected from VSW to VOUT. This diode provides the freewheeling path during the switch-off period. TI recommends a 3.3-A, 50-V Schottky rectifier (e.g., IR 30WQ05F) to minimize forward voltage drop and conduction losses while maintaining efficiency above 90%.
Can the LM2671M-ADJ synchronize to an external clock?
Yes, the LM2671M-ADJ supports external synchronization via the SYNC pin. An external TTL/CMOS clock >275 kHz (e.g., 400 kHz) can be AC-coupled using a 100-pF capacitor and 1-kΩ resistor to ground. When synchronized, the internal 260-kHz oscillator is disabled, and switching follows the external clock - useful for EMI reduction and multi-rail phase alignment.
What thermal considerations apply to the LM2671M-ADJ in SOIC-8 package?
The LM2671M-ADJ in SOIC-8 has a junction-to-ambient thermal resistance (RθJA) of 105°C/W with ~1 in² PCB copper. At 500 mA output and 24 V input, power dissipation is ~1.2 W - resulting in ~126°C junction rise above ambient. To stay within 125°C max TJ, limit ambient temperature or increase copper area; TI confirms copper traces alone suffice for heatsinking under typical conditions.
LM2671M-ADJ 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:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 6.5V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 1.21V
- Voltage - Output (Max):
- 37V
- 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-ADJ FAQ
1.How can I place an order for LM2671M-ADJ through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2671M-ADJ 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-ADJ reliable?
The price and inventory of LM2671M-ADJ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2671M-ADJ is usually 5 days.
3.What payment methods are accepted for LM2671M-ADJ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2671M-ADJ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2671M-ADJ?
LM2671M-ADJ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2671M-ADJ 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-ADJ?
For technical support, including LM2671M-ADJ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2671M-ADJ requirements.
6.How does Aetrix verify that LM2671M-ADJ is sourced from the original manufacturer or authorized distributors?
All LM2671M-ADJ 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-ADJ meets industry standards.
7.What is the process for return or replacement of LM2671M-ADJ?
All LM2671M-ADJ units undergo pre-shipment inspection (PSI). If there is an issue with LM2671M-ADJ, 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-ADJ part is unused and in its original packaging.
Return procedure for LM2671M-ADJ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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