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Texas Instruments LM2671LD-ADJ/NOPB
- Part No.:
- LM2671LD-ADJ/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 16-WFDFN Exposed Pad
- Datasheet:
-
LM2671LD-ADJ/NOPB.pdf
- Description:
- IC REG BUCK ADJ 500MA 16WSON
- Quantity:
- Payment:
- Shipping:
Inventory:1,000
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Product details
Overview
LM2671LD-ADJ/NOPB from Texas Instruments is a monolithic step-down (buck) DC-DC switching regulator IC with adjustable output, delivering up to 500 mA load current, 260 kHz fixed-frequency operation, ±1.5% output voltage tolerance, and 90% typical efficiency at 12 VIN/5 VOUT. It integrates a 0.25 Ω DMOS power switch and supports input voltages from 6.5 V to 40 V - used in industrial power supplies, distributed power architectures, and battery-fed systems requiring stable mid-power conversion.
For engineers reviewing the LM2671LD-ADJ/NOPB datasheet, LM2671LD-ADJ/NOPB pinout, LM2671LD-ADJ/NOPB application, or LM2671LD-ADJ/NOPB equivalent, key selection criteria include its adjustable 1.21 V–37 V output range, soft-start control via external capacitor, TTL-compatible ON/OFF enable, frequency synchronization capability, and thermal/current-limit protection - all critical for robust, layout-efficient buck converter design.
Technical Context
The LM2671LD-ADJ/NOPB implements a current-mode PWM controller with internal 260 kHz oscillator, fixed-frequency operation, and cycle-by-cycle current limiting. Its DMOS power switch features 0.25 Ω RDS(ON) at 25°C and supports duty cycles from 0% to 95%, enabling wide input-to-output voltage ratios while maintaining stability without external compensation.
Feedback is implemented via high-gain error amplifier referenced to precise 1.21 V internal bandgap (±1.5% over temp), with <85 nA bias current ensuring minimal divider network error. The SYNC pin accepts external TTL/CMOS clocks >275 kHz to override internal oscillator and align ripple spectrum - essential for EMI-sensitive communications systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 500 mA maximum continuous - ensures full-rated load delivery without derating in standard PCB layouts with adequate copper area. |
| Input Voltage Range | 6.5 V to 40 V - supports wide-range industrial, automotive, and telecom inputs including unregulated 24 V and 36 V rails. |
| Output Voltage Range | 1.21 V to 37 V (adjustable) - set by external resistor divider; enables single-part flexibility across diverse system voltage domains. |
| Switching Frequency | 260 kHz (±10%) - balances size of external inductor/capacitor against EMI and efficiency; allows use of low-cost, standard 22–68 µH shielded inductors. |
| Feedback Reference | 1.21 V ±1.5% - high-accuracy internal reference minimizes output error contribution from resistor tolerance and temperature drift. |
| Quiescent Current | 3.6 mA typical (active), 50 µA typical (shutdown) - enables low-noise standby operation and battery-backed subsystems with extended hold-up time. |
| Thermal Protection | Internal thermal shutdown - automatically disables switching above 150°C junction temperature, preventing permanent damage during overload or poor heatsinking. |
Pinout & Package
LM2671LD-ADJ/NOPB is housed in an 8-pin SOIC (D package), 4.90 mm × 3.91 mm body size, with exposed thermal pad not present - thermal management relies on PCB copper area per TI AN-1187 guidelines.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CB | Bootstrap capacitor connection | Connects 100 nF ceramic capacitor to VSW; provides gate drive voltage >VIN to fully enhance internal DMOS switch and minimize conduction loss. |
| SS | Soft-start control | Accepts external capacitor to GND; controls output voltage ramp rate and prevents inrush current during startup - floating disables soft-start. |
| SYNC | Frequency synchronization input | TTL/CMOS-compatible input; overrides internal 260 kHz oscillator when driven externally (>275 kHz); enables EMI filtering consistency and spectral placement. |
| FB | Feedback sense input | High-impedance input (85 nA bias) referenced to 1.21 V; connects to resistor divider midpoint to program output voltage precisely. |
| ON/OFF | Enable/disable control | Active-high logic input; ≥1.4 V enables regulation, ≤0.8 V forces shutdown with 50 µA standby current; internal 20 µA pull-up simplifies interface. |
| VSW | Switch node output | Drain of internal DMOS FET; connects to inductor and Schottky diode cathode; swings from VIN to ~−0.5 V during switching - requires short, low-inductance routing. |
| GND | Power ground | Primary return path for input/output capacitors and internal circuitry; must be connected to low-impedance PCB ground plane to minimize noise and ensure stability. |
| VIN | Input supply | Connects to main DC input rail (6.5–40 V); requires local 22 µF tantalum bypass capacitor placed adjacent to pin to suppress high-frequency switching noise. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated DMOS power switch | 0.25 Ω RDS(ON) at 25°C reduces conduction loss and eliminates need for external MOSFET - simplifies BOM and improves thermal performance. |
| Adjustable output voltage | 1.21 V to 37 V range set by two external resistors - enables one footprint to support multiple system rails without redesigning PCB layout. |
| Fixed 260 kHz switching | Enables predictable EMI profile and consistent filter component selection; avoids subharmonic oscillation through current-mode control architecture. |
| Soft-start and sync capability | External capacitor sets controlled output ramp; SYNC pin allows system-level clock alignment - critical for multi-rail sequencing and EMC compliance. |
| Comprehensive protection | Includes cycle-by-cycle current limit, thermal shutdown, and under-voltage lockout - ensures safe operation during fault conditions without external circuitry. |
Applications
| Industrial Power Supply | Automotive Body Control Module |
|---|---|
|
Use Scenario: Converts 24 V vehicle battery or 36 V industrial bus to 3.3 V/5 V for microcontrollers and sensors. IC Role / Device Role / Timing Role: Primary step-down regulator providing isolated, regulated DC power with fast transient response to load steps. Use Value: Delivers 500 mA at >90% efficiency with no external heat sink required - reduces board space and thermal design complexity in sealed enclosures. |
Use Scenario: Powers CAN transceivers, LIN interfaces, and door/window control ICs in 12 V automotive systems. IC Role / Device Role / Timing Role: Buck converter supplying clean, stable voltage to communication peripherals with tight ripple requirements. Use Value: 260 kHz fixed frequency enables predictable EMI filtering; SYNC pin allows synchronization to vehicle clock domain to avoid beat frequencies. |
| Distributed Telecom Power | Test & Measurement Equipment |
|
Use Scenario: Generates intermediate 5 V or 12 V rails from 48 V backplane in modular telecom line cards. IC Role / Device Role / Timing Role: Efficient preregulator stepping down high-input voltage before LDO post-regulation. Use Value: Wide 6.5–40 V input range accommodates 48 V nominal with ±10% variation; ±1.5% output tolerance ensures downstream LDO headroom remains sufficient. |
Use Scenario: Supplies precision analog circuitry (ADCs, DACs, op-amps) in portable bench instruments with battery + adapter operation. IC Role / Device Role / Timing Role: Low-noise, well-regulated DC source with soft-start to prevent measurement glitches during power-on. Use Value: 50 µA shutdown current extends battery life; FB pin's 85 nA bias minimizes resistor-divider error - preserving absolute accuracy in calibration paths. |
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-ADJ/NOPB | Same pinout, 260 kHz, but rated for 1 A output current and includes improved thermal performance in SOIC-8 package. | Better suited for higher-load applications where 500 mA margin is insufficient; requires verification of inductor saturation current and PCB copper area. | Select when load exceeds 450 mA continuously or ambient temperature exceeds 85°C. |
| TPS5430DDAR | 3 A output, 500 kHz switching, integrated high-side FET, but requires external compensation and lacks SYNC pin. | Higher power density and faster transient response, but increased design complexity and no frequency synchronization capability. | Choose for compact, high-current designs where EMI spectral control is secondary to size and output capability. |
Compared with LM2672MX-ADJ/NOPB, the LM2671LD-ADJ/NOPB offers lower cost and simpler design at 500 mA, while TPS5430DDAR trades ease-of-use for higher current and speed - making LM2671LD-ADJ/NOPB optimal for cost-sensitive, thermally constrained, or EMI-controlled mid-power applications.
Availability
LM2671LD-ADJ/NOPB is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, and telecom infrastructure requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LM2671LD-ADJ/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 engineers needing easy-to-use, highly efficient, minimum-component-count DC-DC buck regulators for industrial, automotive, and communications systems.
FAQ
What is the maximum input voltage rating for LM2671LD-ADJ/NOPB?
The absolute maximum input voltage for LM2671LD-ADJ/NOPB is 45 V, but the recommended operating range is 6.5 V to 40 V. Operation above 40 V risks exceeding internal device stress limits and may compromise long-term reliability - TI specifies 40 V as the upper bound for guaranteed performance across temperature and load conditions.
Can LM2671LD-ADJ/NOPB be synchronized to an external clock?
Yes, LM2671LD-ADJ/NOPB supports external frequency synchronization via its SYNC pin. An external TTL/CMOS clock signal >275 kHz (e.g., 300–400 kHz) can override the internal 260 kHz oscillator. This feature enables EMI spectrum alignment and eliminates beat frequencies in multi-rail systems - confirmed in Section 8.3.5 of the SNVS008L datasheet.
What is the feedback reference voltage of LM2671LD-ADJ/NOPB?
The LM2671LD-ADJ/NOPB uses a precision internal bandgap reference of 1.21 V ±1.5% over temperature and line/load conditions. This value appears as VFB in Section 7.8 of the datasheet and serves as the setpoint for the error amplifier - external resistor dividers scale the output voltage relative to this reference.
Does LM2671LD-ADJ/NOPB require external compensation components?
No, LM2671LD-ADJ/NOPB incorporates patented internal frequency compensation and requires only five external components: input capacitor, output capacitor, inductor, catch diode, and feedback resistor divider. This eliminates the need for external compensation networks - a core design simplification highlighted in the "Simple and Easy to Design With" feature list.
How does the soft-start function work on LM2671LD-ADJ/NOPB?
The soft-start function on LM2671LD-ADJ/NOPB is controlled by an external capacitor connected between the SS pin and GND. Charging this capacitor linearly ramps the internal reference voltage, causing the output voltage to rise gradually - preventing inrush current and input voltage droop. If unused, the SS pin may be left floating, disabling soft-start entirely.
LM2671LD-ADJ/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 16-WFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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:
- 16-WSON (5x5)
LM2671LD-ADJ/NOPB FAQ
1.How can I place an order for LM2671LD-ADJ/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2671LD-ADJ/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 LM2671LD-ADJ/NOPB reliable?
The price and inventory of LM2671LD-ADJ/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2671LD-ADJ/NOPB is usually 5 days.
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4.How is shipping managed for LM2671LD-ADJ/NOPB?
LM2671LD-ADJ/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2671LD-ADJ/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 LM2671LD-ADJ/NOPB?
For technical support, including LM2671LD-ADJ/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2671LD-ADJ/NOPB requirements.
6.How does Aetrix verify that LM2671LD-ADJ/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2671LD-ADJ/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 LM2671LD-ADJ/NOPB meets industry standards.
7.What is the process for return or replacement of LM2671LD-ADJ/NOPB?
All LM2671LD-ADJ/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2671LD-ADJ/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 LM2671LD-ADJ/NOPB part is unused and in its original packaging.
Return procedure for LM2671LD-ADJ/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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