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Texas Instruments LM2671MX-3.3/NOPB
- Part No.:
- LM2671MX-3.3/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM2671MX-3.3/NOPB.pdf
- Description:
- IC REG BUCK 3.3V 500MA 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,854
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Product details
Overview
LM2671MX-3.3/NOPB from Texas Instruments is a monolithic step-down (buck) DC-DC switching regulator IC delivering a fixed 3.3-V output at up to 500 mA, with ±1.5% output voltage tolerance, 260-kHz fixed-frequency operation, and 86% efficiency at 12-V input/500-mA load. It integrates a 0.25-Ω DMOS power switch and supports TTL shutdown for low-power standby in industrial power supplies and embedded systems.
For engineers reviewing the LM2671MX-3.3/NOPB datasheet, LM2671MX-3.3/NOPB pinout, LM2671MX-3.3/NOPB application, or LM2671MX-3.3/NOPB equivalent, key selection considerations include input voltage range (6.5 V to 40 V), thermal shutdown protection, soft-start control via external capacitor, SYNC capability for frequency synchronization, and SOIC-8 package compatibility with standard PCB layouts.
Technical Context
The LM2671MX-3.3/NOPB implements a current-mode PWM controller with an internal 260-kHz oscillator and cycle-by-cycle current limiting. Its DMOS output switch enables high-efficiency buck conversion without external gate drivers, while the integrated feedback amplifier eliminates need for external error amplifiers in fixed-output configurations.
Functional modes include active regulation (ON/OFF ≥ 1.4 V) and shutdown (ON/OFF ≤ 0.8 V), with 50-μA standby current. The FB pin connects directly to the output capacitor for fixed 3.3-V regulation, and the CB–VSW bootstrap network ensures full enhancement of the high-side MOSFET.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3 V ±1.5% over line, load, and temperature - ensures stable logic supply for microcontrollers and FPGAs. |
| Max Output Current | 500 mA - supports moderate-power digital subsystems without external current boosting. |
| Input Voltage Range | 6.5 V to 40 V - accommodates wide-range industrial DC inputs including 12-V, 24-V, and 36-V rails. |
| Switching Frequency | 260 kHz (±10%) - enables use of compact, off-the-shelf inductors and reduces EMI compared to lower-frequency alternatives. |
| RDS(ON) | 0.25 Ω typical - minimizes conduction loss and self-heating at full load, enabling copper-trace-only thermal management. |
| Quiescent Current | 3.6 mA typical - balances light-load efficiency and startup responsiveness in always-on applications. |
| Standby Current | 50 μA typical - allows ultra-low-power sleep mode when ON/OFF pin is pulled low. |
| Oscillator Sync Range | Up to 400 kHz - permits precise ripple frequency alignment with system clocks or noise-sensitive receivers. |
Pinout & Package
LM2671MX-3.3/NOPB is packaged in an 8-pin SOIC (D package), 4.90 mm × 3.91 mm body size, with exposed pad not present. Thermal resistance RθJA = 105°C/W under standard 1-in² copper layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CB | Bootstrap capacitor connection | Connects 100-nF ceramic capacitor to VSW to generate gate drive voltage > VIN for high-side DMOS switch. |
| SS | Soft-start control | Accepts external capacitor to linearly ramp output voltage at startup, preventing inrush current and overshoot. |
| SYNC | Frequency synchronization input | Accepts TTL/CMOS clock signal to override internal 260-kHz oscillator; disables current-limit foldback when active. |
| FB | Feedback sense input | Internally tied to 3.3-V reference; connect directly to output capacitor for fixed-output regulation - no external resistors required. |
| ON/OFF | Enable/disable control | TTL-compatible input: ≥1.4 V enables regulation; ≤0.8 V disables with 50-μA standby draw; internal 20-μA pull-up. |
| VSW | Switch node output | Drives external inductor and Schottky catch diode; swings from VIN to ~−0.4 V during switching transitions. |
| VIN | Main power input | Supplies both power stage and internal circuitry; requires local 22-μF tantalum bypass capacitor with short GND path. |
| GND | Power ground | Common return for input/output capacitors, inductor, and internal circuitry; must be low-inductance plane for EMI control. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated DMOS power switch | Eliminates need for external MOSFET driver and discrete switch, reducing BOM count and layout complexity. |
| Fixed-frequency PWM control | Enables predictable EMI filtering and consistent inductor sizing across designs using 260-kHz fundamental. |
| Internal compensation | Removes requirement for external compensation network - only 5 external components needed for full design. |
| Thermal shutdown + current limit | Protects against sustained overload or short-circuit without external sensing circuitry or fault latching. |
| Soft-start with external capacitor | Allows precise control of output voltage ramp rate to prevent system reset or rail collapse during power-up. |
| TTL-compatible enable input | Supports direct interfacing with microcontroller GPIOs or system power sequencers without level-shifting. |
Applications
| Industrial PLC I/O Module Power | Automotive Body Control Unit (BCU) |
|---|---|
Use Scenario: Powers 3.3-V microcontroller, CAN transceiver, and sensor interface circuitry in DIN-rail mounted programmable logic controllers. IC Role / Device Role / Timing Role: Primary 3.3-V buck regulator converting 24-V DC bus to logic rail; provides regulated supply independent of input fluctuations. Use Value: ±1.5% output tolerance ensures reliable MCU operation across temperature; 40-V max input withstands load-dump transients per ISO 7637-2. | Use Scenario: Supplies 3.3-V domain for door module ECUs handling window lift, mirror control, and interior lighting. IC Role / Device Role / Timing Role: Secondary buck converter downstream of main 5-V rail, delivering clean, low-noise 3.3-V supply for mixed-signal ASICs. Use Value: 260-kHz switching avoids AM radio band interference; soft-start prevents false wake-up of CAN nodes during ignition cycling. |
| Point-of-Load for FPGA Core Logic | Medical Patient Monitor Auxiliary Rail |
Use Scenario: Generates dedicated 3.3-V core voltage for low-power FPGA configuration and I/O banks in portable diagnostic equipment. IC Role / Device Role / Timing Role: Compact, thermally efficient point-of-load regulator placed adjacent to FPGA package to minimize IR drop and noise coupling. Use Value: 0.25-Ω RDS(ON) and copper-trace-only thermal design reduce board area vs. linear regulators; 500-mA rating covers peak FPGA I/O activity. | Use Scenario: Provides isolated 3.3-V supply for touch-screen controller and data acquisition front-end in Class II medical devices. IC Role / Device Role / Timing Role: Safety-critical auxiliary regulator with thermal shutdown and current limit ensuring fail-safe shutdown under fault conditions. Use Value: 50-μA standby current extends battery life in portable monitors; ±1.5% tolerance maintains ADC reference stability during long-term monitoring. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2672MX-3.3/NOPB | Same pinout, 3.3-V fixed output, but rated for 1-A load and includes improved current-limit accuracy. | Better suited for higher-current loads where 500-mA margin is insufficient; same SOIC-8 footprint. | Select when future-proofing for load growth or requiring tighter current-limit threshold consistency. |
| TPS54331DR | 3.5-V to 28-V input, 3-A output, adjustable VOUT, 570-kHz switching, integrated high-side FET. | Higher performance and flexibility but requires external feedback resistors and compensation; larger solution size. | Choose when needing >500-mA output, wider input range, or programmable output voltage in new designs. |
Compared with LM2671MX-3.3/NOPB, LM2672MX-3.3/NOPB offers doubled current capacity in identical packaging, while TPS54331DR trades simplicity for higher integration and configurability - making LM2671MX-3.3/NOPB optimal for cost-sensitive, space-constrained 500-mA fixed-output applications.
Availability
LM2671MX-3.3/NOPB is available at Aetrix Electronics and suitable for industrial automation, automotive electronics, and medical instrumentation requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.
Supply support for LM2671MX-3.3/NOPB 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 LM2671 series belongs to TI's SIMPLE SWITCHER® family, designed specifically for ease-of-use, minimal external component count, and robust operation in harsh industrial and automotive environments.
FAQ
What is the maximum input voltage rating for LM2671MX-3.3/NOPB?
The absolute maximum input voltage for LM2671MX-3.3/NOPB is 45 V, but the recommended operating range is 6.5 V to 40 V. Operation above 40 V risks exceeding safe junction temperature or violating SOA limits, especially under high ambient conditions or heavy load. Always observe derating curves in the datasheet thermal section when operating near 40 V.
Does LM2671MX-3.3/NOPB require external feedback resistors?
No, LM2671MX-3.3/NOPB does not require external feedback resistors. As a fixed-output variant, it has internal resistor dividers that set the 3.3-V regulation point; the FB pin must be connected directly to the output capacitor for proper closed-loop control.
Can LM2671MX-3.3/NOPB synchronize to an external clock?
Yes, LM2671MX-3.3/NOPB supports external clock synchronization via the SYNC pin. An external TTL/CMOS-compatible signal (0 V to >3 V) can be ac-coupled to SYNC to force switching at frequencies up to 400 kHz, enabling EMI reduction and spectral alignment in noise-sensitive systems.
What thermal management is required for LM2671MX-3.3/NOPB at full 500-mA load?
At full 500-mA load and 12-V input, LM2671MX-3.3/NOPB dissipates approximately 0.45 W. With RθJA = 105°C/W in SOIC-8, this yields ~47°C rise above ambient - manageable with 1 in² of 2-oz copper on the top layer connected to GND pins. No heatsink or airflow is required under typical industrial ambient conditions (≤70°C).
Is LM2671MX-3.3/NOPB pin-compatible with other LM2671 fixed-output variants?
Yes, all LM2671 fixed-output versions (3.3 V, 5 V, 12 V) share identical SOIC-8, PDIP-8, and WSON-16 pinouts and electrical interfaces. Only the internal feedback divider differs - allowing direct substitution when output voltage requirements change, provided input/output capacitors and inductor ratings remain appropriate.
LM2671MX-3.3/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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):
- 3.3V
- 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
LM2671MX-3.3/NOPB FAQ
1.How can I place an order for LM2671MX-3.3/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2671MX-3.3/NOPB 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 LM2671MX-3.3/NOPB reliable?
The price and inventory of LM2671MX-3.3/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2671MX-3.3/NOPB is usually 5 days.
3.What payment methods are accepted for LM2671MX-3.3/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2671MX-3.3/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2671MX-3.3/NOPB?
LM2671MX-3.3/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2671MX-3.3/NOPB 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 LM2671MX-3.3/NOPB?
For technical support, including LM2671MX-3.3/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2671MX-3.3/NOPB requirements.
6.How does Aetrix verify that LM2671MX-3.3/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2671MX-3.3/NOPB 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 LM2671MX-3.3/NOPB meets industry standards.
7.What is the process for return or replacement of LM2671MX-3.3/NOPB?
All LM2671MX-3.3/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2671MX-3.3/NOPB, 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 LM2671MX-3.3/NOPB part is unused and in its original packaging.
Return procedure for LM2671MX-3.3/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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