My Inquiry
My Account
Texas Instruments LM2671N-3.3/NOPB
- Part No.:
- LM2671N-3.3/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
LM2671N-3.3/NOPB.pdf
- Description:
- IC REG BUCK 3.3V 500MA 8PDIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,425
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM2671N-3.3/NOPB from Texas Instruments is a monolithic step-down (buck) DC-DC switching regulator 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 wide 6.5–40-V input range for industrial power conversion.
For engineers reviewing the LM2671N-3.3/NOPB datasheet, LM2671N-3.3/NOPB pinout, LM2671N-3.3/NOPB application, or LM2671N-3.3/NOPB equivalent, key selection considerations include its SOIC-8 package compatibility, TTL-compatible ON/OFF control, soft-start capability via external capacitor, and requirement for only five external components in standard buck configuration.
Technical Context
The LM2671N-3.3/NOPB implements a current-mode PWM controller with internal 260-kHz oscillator and integrated high-side DMOS switch. Its feedback loop uses a direct connection from FB pin to output (no external divider), enabling stable regulation of the fixed 3.3-V output across line (6.5–40 V) and load (20–500 mA) variations.
Functional modes include active regulation and low-power shutdown (50-μA standby), triggered by TTL-level ON/OFF pin voltage thresholds (1.4 V typical). Protection features include cycle-by-cycle current limiting (0.62–1.2 A), thermal shutdown, and frequency foldback under extreme overload.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3 V ±1.5% over full temperature and load range - ensures reliable logic supply for 3.3-V microcontrollers and FPGAs. |
| Max Output Current | 500 mA continuous - sufficient for powering multiple digital ICs or small subsystems without external boost stages. |
| Input Voltage Range | 6.5 V to 40 V - supports unregulated 12-V/24-V industrial rails and automotive battery-supplied systems with transients. |
| Switching Frequency | 260 kHz (±10%) - enables use of compact, off-the-shelf inductors and reduces EMI compared to lower-frequency alternatives. |
| Efficiency | 86% at VIN = 12 V, IOUT = 500 mA - minimizes thermal dissipation; PCB copper traces serve as sole heatsink in most layouts. |
| Quiescent Current | 3.6 mA typical in active mode; 50 μA in shutdown - supports low-power wake-on-event architectures. |
| ON/OFF Threshold | 1.4 V (typical) - compatible with standard CMOS/TTL logic levels for seamless system-level enable control. |
Pinout & Package
LM2671N-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. Pin functions are validated per TI SNVS008L Rev L datasheet.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CB (Pin 1) | Bootstrap capacitor node | Connects 100-nF ceramic capacitor to VSW to gate-drive high-side DMOS switch fully ON - critical for achieving specified RDS(ON) and efficiency. |
| SS (Pin 2) | Soft-start control | Accepts external capacitor to linearly ramp output voltage at startup - prevents inrush current and stabilizes downstream sequencing. |
| SYNC (Pin 3) | Frequency synchronization input | Allows external clock injection (>275 kHz) to lock switching frequency - essential for EMI reduction in noise-sensitive systems. |
| FB (Pin 4) | Feedback sense | Internally tied to 3.3-V reference; connected directly to output capacitor - eliminates need for resistor divider and simplifies layout. |
| ON/OFF (Pin 5) | Enable/disable control | TTL-compatible input; <0.8 V disables regulator with 50-μA standby draw - enables power-domain isolation in multi-rail systems. |
| VSW (Pin 8) | Switch node | Drives external Schottky diode and inductor - high dv/dt node requiring tight layout and ground plane separation to minimize ringing. |
| GND (Pin 6) | Power ground | Primary return path for input/output capacitors and switch current - must be short, low-inductance connection to minimize noise coupling. |
| VIN (Pin 7) | Input supply | Accepts 6.5–40 V DC; requires local 22-μF tantalum bypass capacitor - feeds both power switch and internal bias circuitry. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 0.25-Ω DMOS switch | Reduces conduction losses and eliminates need for external MOSFET - lowers BOM count and improves thermal performance at 500-mA load. |
| Patented internal frequency compensation | Enables stable operation with standard external components - no loop compensation design required for basic buck topology. |
| Soft-start with external capacitor | Provides controlled output voltage ramp-up - prevents overshoot and avoids false triggering of downstream reset circuits. |
| TTL shutdown with 50-μA standby | Supports system-level power gating - allows deep sleep states while maintaining fast wake-up response (<100 μs). |
| Thermal shutdown + current limit | Protects against sustained overload or ambient overheating - latches off until junction cools, preventing catastrophic failure. |
Applications
| Industrial PLC I/O Module Power | Automotive Body Control Unit (BCU) |
|---|---|
|
Use Scenario: Powers isolated 3.3-V logic rails for digital input/output buffers and CAN transceivers in DIN-rail mounted controllers. IC Role / Device Role / Timing Role: Primary step-down regulator converting 24-V field bus to clean 3.3-V supply for microcontroller peripherals. Use Value: High efficiency (86%) and wide input range (6.5–40 V) accommodate 24-V nominal with ±25% brownout and surge conditions. |
Use Scenario: Supplies 3.3-V domain for microcontroller, EEPROM, and LIN transceivers in door module electronics. IC Role / Device Role / Timing Role: Fixed-output buck converter replacing linear regulator to reduce heat generation in confined plastic housings. Use Value: 500-mA capability and 50-μA shutdown current meet OEM requirements for quiescent current <100 μA in vehicle-off state. |
| Point-of-Load for FPGA Core Logic | Medical Patient Monitor Auxiliary Rail |
|
Use Scenario: Generates 3.3-V auxiliary rail for FPGA configuration memory, JTAG interface, and peripheral I/O banks. IC Role / Device Role / Timing Role: Secondary regulated supply decoupled from main 5-V/12-V rails - ensures noise isolation for sensitive logic. Use Value: 260-kHz switching frequency enables use of small 68-μH inductors and avoids interference with FPGA clock domains. |
Use Scenario: Provides isolated 3.3-V supply for low-power sensor signal conditioning and display controller in Class II medical devices. IC Role / Device Role / Timing Role: Safety-critical auxiliary regulator with thermal shutdown and current limiting - meets IEC 60601-1 creepage/clearance requirements. Use Value: ±1.5% output tolerance and stable regulation across temperature ensure accurate ADC reference and display timing integrity. |
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 architecture but in SOIC-8 with improved thermal resistance (RθJA = 105°C/W vs. 110°C/W); identical electrical specs. | Preferred for higher ambient temperature environments where junction temperature margin is critical. | Select when thermal derating above 85°C ambient is required; pinout and footprint identical. |
| TPS54331DR | 3-A synchronous buck with adjustable output; 570-kHz switching; requires external feedback resistors and has different pinout. | Suitable for higher-current or adjustable-voltage designs; not a drop-in replacement due to different control scheme and package. | Choose only if >500-mA output or programmability is needed; requires PCB redesign and new layout validation. |
Compared with LM2672MX-3.3/NOPB, the LM2671N-3.3/NOPB offers identical functionality in legacy SOIC-8 packaging but with slightly higher thermal resistance; versus TPS54331DR, it trades current capability and flexibility for simplicity, lower component count, and proven reliability in fixed-output industrial deployments.
Availability
LM2671N-3.3/NOPB is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and medical auxiliary power applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for LM2671N-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 experience in high-reliability power conversion ICs.
The LM2671 series belongs to TI's SIMPLE SWITCHER® family, designed specifically for ease-of-use in cost-sensitive, medium-power DC-DC conversion - emphasizing minimal external components, robust protection, and rapid time-to-market.
FAQ
What is the maximum input voltage rating for the LM2671N-3.3/NOPB?
The LM2671N-3.3/NOPB has an absolute maximum input voltage rating of 45 V, with recommended operating range from 6.5 V to 40 V. Operation beyond 40 V risks exceeding safe operating area limits and may trigger internal protection or cause permanent damage. The 40-V upper limit ensures reliable performance across industrial and automotive transients while maintaining specified efficiency and regulation.
Does the LM2671N-3.3/NOPB require an external feedback resistor network?
No, the LM2671N-3.3/NOPB does not require external feedback resistors. As a fixed-output variant, its FB pin is internally connected to a precision 3.3-V reference; the pin must be connected directly to the output capacitor for regulation. This eliminates resistor tolerance errors and simplifies layout - a key differentiator from adjustable regulators like the LM2671M-ADJ.
Can the LM2671N-3.3/NOPB synchronize to an external clock?
Yes, the LM2671N-3.3/NOPB supports external frequency synchronization via the SYNC pin (Pin 3). An external TTL/CMOS clock signal above 275 kHz can be ac-coupled to this pin to lock the internal 260-kHz oscillator - enabling EMI reduction and predictable ripple placement in noise-sensitive applications such as communications equipment.
What thermal considerations apply to the LM2671N-3.3/NOPB in SOIC-8 package?
The LM2671N-3.3/NOPB in SOIC-8 (D package) has a junction-to-ambient thermal resistance (RθJA) of 105°C/W under standard JEDEC test conditions. To maintain TJ ≤ 125°C at 500-mA load, PCB layout must include ≥1 square inch of 2-oz copper connected to GND pins. Thermal vias under the GND pad further reduce resistance - critical for continuous operation in enclosed enclosures.
Is the LM2671N-3.3/NOPB suitable for automotive applications?
Yes, the LM2671N-3.3/NOPB is widely used in automotive body electronics (e.g., door modules, lighting controls) due to its 40-V input rating, –40°C to +125°C operating junction temperature range, and built-in protections (thermal shutdown, current limit). While not AEC-Q200 qualified itself, it meets functional requirements for non-safety-critical 12-V/24-V subsystems when properly derated and validated per OEM specifications.
LM2671N-3.3/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- 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:
- Through Hole
- Supplier Device Package:
- 8-PDIP
LM2671N-3.3/NOPB FAQ
1.How can I place an order for LM2671N-3.3/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2671N-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 LM2671N-3.3/NOPB reliable?
The price and inventory of LM2671N-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 LM2671N-3.3/NOPB is usually 5 days.
3.What payment methods are accepted for LM2671N-3.3/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2671N-3.3/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2671N-3.3/NOPB?
LM2671N-3.3/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2671N-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 LM2671N-3.3/NOPB?
For technical support, including LM2671N-3.3/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2671N-3.3/NOPB requirements.
6.How does Aetrix verify that LM2671N-3.3/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2671N-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 LM2671N-3.3/NOPB meets industry standards.
7.What is the process for return or replacement of LM2671N-3.3/NOPB?
All LM2671N-3.3/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2671N-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 LM2671N-3.3/NOPB part is unused and in its original packaging.
Return procedure for LM2671N-3.3/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM2671N-3.3/NOPB 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…
