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Texas Instruments LM3671MFX-2.5/NOPB
- Part No.:
- LM3671MFX-2.5/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LM3671MFX-2.5/NOPB.pdf
- Description:
- IC REG BUCK 2.5V 600MA SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:3,313
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Product details
Overview
LM3671MFX-2.5/NOPB from Texas Instruments is a fixed-output 2.5 V, 600-mA synchronous step-down DC-DC converter optimized for single Li-Ion battery-powered portable electronics. It operates from 2.7 V to 5.5 V input, delivers 2-MHz fixed-frequency PWM switching with automatic PFM mode transition below ~80 mA load, and achieves 16 µA typical quiescent current in light-load operation - enabling extended battery life in mobile phones and handheld instruments.
For engineers reviewing the LM3671MFX-2.5/NOPB datasheet, LM3671MFX-2.5/NOPB pinout, LM3671MFX-2.5/NOPB application, or LM3671MFX-2.5/NOPB equivalent, key selection criteria include its USON-6 package footprint, internal 0.5 V reference with ±4% feedback voltage tolerance, 1020 mA peak switch current limit, thermal shutdown at 150°C (typ), and compatibility with only three external components: one 2.2 µH inductor and two ceramic capacitors.
Technical Context
The LM3671MFX-2.5/NOPB implements voltage-mode control with input-voltage feed-forward compensation to maintain stable regulation across 2.7–5.5 V input range. Its integrated PFET/NFET power stage enables synchronous rectification, eliminating external diode losses and supporting high efficiency at low output voltages like 2.5 V.
It features dual-mode operation: fixed 2-MHz PWM for low-noise, high-accuracy regulation above ~80 mA load; and hysteretic PFM for ultra-low quiescent current (16 µA typ) during standby or light-load conditions. Soft-start limits inrush current via stepped current-limit ramp (70 → 140 → 280 → 1020 mA), and internal thermal shutdown engages at 150°C (typ) with hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 2.5 V ±4% (FB pin internally connected to 0.5 V reference; no external resistor divider required) |
| Max Output Current | 600 mA continuous - supports core logic rails in smartphones and portable medical devices |
| Input Voltage Range | 2.7 V to 5.5 V - compatible with fully discharged to fully charged single Li-Ion cells (2.7–4.2 V) plus 3.3 V/5 V system rails |
| Switching Frequency | 2 MHz (typ), ±0.4 MHz variation - enables use of tiny 2.2 µH inductors and 10 µF ceramic output capacitors |
| Quiescent Current | 16 µA (typ) in PFM mode - extends battery runtime in always-on sensor or standby subsystems |
| Shutdown Current | 0.01 µA (typ) - reduces system leakage when powered off or in deep sleep |
| Peak Switch Current Limit | 1020 mA (typ) - provides robust short-circuit and overload protection without external sensing |
Pinout & Package
LM3671MFX-2.5/NOPB uses the 6-pin USON (NKH) package: 2.00 mm × 2.00 mm body, 0.5 mm pitch, wettable flank terminals for automated optical inspection. Thermal resistance RθJA = 174.7°C/W on 4-layer board.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Power Input | Connects to input filter capacitor; accepts 2.7–5.5 V supply; powers internal bias circuitry and PFET gate driver |
| GND | Power Ground | Primary return path for input current, inductor discharge, and internal regulator ground - must be low-impedance connection |
| EN | Digital Enable | Active-high logic input; device enabled when >1 V, shutdown when <0.4 V; 0.01 µA input leakage minimizes control-line loading |
| FB | Feedback Input | Internally tied to 0.5 V reference for fixed 2.5 V output; no external resistors needed - simplifies layout and improves accuracy |
| SW | Switch Node | Connection to internal PFET drain and NFET source; drives external inductor; requires low-inductance routing to minimize EMI |
| SGND | Signal Ground | Separate feedback ground terminal - isolates FB reference path from high-current GND return noise |
Key Features
| Feature | Design Value |
|---|---|
| Internal Synchronous Rectification | Eliminates external Schottky diode; reduces conduction loss at 2.5 V output - improves full-load efficiency by ≥8% vs asynchronous design |
| Automatic PFM-PWM Mode Switching | Seamlessly transitions at ~80 mA load; maintains >85% efficiency from 1 mA to 600 mA without manual mode control |
| Integrated Soft Start | Staged current-limit ramp prevents input rail sag and output overshoot during power-up - eliminates need for external timing components |
| Thermal & Overcurrent Protection | Auto-recovering thermal shutdown (150°C trip) and cycle-by-cycle current limiting (1020 mA peak) protect against sustained overload or PCB overheating |
| Ultra-Small BOM | Only three external passive components required: 2.2 µH shielded inductor, 4.7 µF input ceramic cap, 10 µF output ceramic cap - reduces solution size to <12 mm² |
Applications
| Mobile Phone Core Power | Portable Medical Sensor Rail |
|---|---|
Use Scenario: Powering ARM Cortex-M4 microcontroller core and DDR I/O at 2.5 V from shared Li-Ion battery. IC Role / Device Role / Timing Role: Primary buck regulator delivering regulated 2.5 V with fast transient response to handle CPU burst loads. Use Value: 2-MHz switching enables sub-10 µs load-step recovery; 16 µA PFM current extends standby time between patient measurements. |
Use Scenario: Supplying analog front-end (AFE) and low-power ADC in handheld blood glucose meter. IC Role / Device Role / Timing Role: Low-noise, low-quiescent power source for precision signal chain - critical for <1 LSB measurement accuracy. Use Value: Fixed 2.5 V output eliminates resistor-divider drift; internal soft start prevents sensor initialization errors during battery insertion. |
| Wireless Audio Codec Supply | Automotive Infotainment Display Backlight Bias |
Use Scenario: Generating clean 2.5 V rail for Bluetooth audio codec IC in wireless earbuds. IC Role / Device Role / Timing Role: Efficient, compact DC-DC stage replacing LDO to extend talk time within tight thermal envelope. Use Value: Synchronous rectification achieves >92% efficiency at 200 mA - reduces die temperature rise by 12°C vs LDO alternative. |
Use Scenario: Providing stable 2.5 V bias for LED driver IC in automotive center-stack display module. IC Role / Device Role / Timing Role: Secondary regulated supply derived from 5 V system rail; must survive cold-crank (4.5 V min) and load-dump transients. Use Value: 2.7–5.5 V input range ensures operation during cranking; thermal shutdown protects against enclosed dashboard heat buildup. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down DC-DC converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS62231DRYR | Fixed 2.5 V output, 600 mA, 3-MHz switching, 17 µA IQ - same USON-6 package but higher fSW and slightly higher quiescent current | Optimized for ultra-thin wearables requiring smallest possible inductor; less tolerant of input ripple due to higher fSW | Select when board space is constrained to <8 mm² and 3-MHz EMI filtering is already implemented. |
| AP63202WU-7 | Fixed 2.5 V output, 2-A max, 2-MHz switching, 25 µA IQ - WLCSP-6 package (1.5 × 1.5 mm), higher current capability | Targets higher-power applications like multi-sensor hubs; WLCSP requires advanced assembly but saves 30% board area | Select when future-proofing for 1–2 A loads or when footprint reduction outweighs rework complexity of WLCSP. |
Compared with LM3671MFX-2.5/NOPB, TPS62231DRYR offers faster transient response at the cost of marginally higher light-load current, while AP63202WU-7 trades package familiarity for higher current headroom and smaller footprint - making LM3671MFX-2.5/NOPB optimal for cost-sensitive, production-ready 600-mA portable designs with proven USON-6 manufacturability.
Availability
LM3671MFX-2.5/NOPB is available at Aetrix Electronics and suitable for mobile phone power management, portable medical instrumentation, and wireless audio subsystems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for LM3671MFX-2.5/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 designing analog ICs, embedded processors, and connectivity solutions for industrial, automotive, and consumer markets.
The LM3671 product line delivers highly integrated, ultra-compact DC-DC converters targeting battery-powered portable electronics where minimal external components, low quiescent current, and small footprint are critical design requirements.
FAQ
What is the recommended input capacitor for LM3671MFX-2.5/NOPB?
The LM3671MFX-2.5/NOPB datasheet specifies a 4.7 µF X5R/X7R ceramic capacitor placed as close as possible to the VIN and GND pins. This value ensures stable operation across the 2.7–5.5 V input range and suppresses high-frequency switching noise. Larger values (e.g., 10 µF) may improve ripple rejection but are not required for basic functionality of the LM3671MFX-2.5/NOPB.
Does LM3671MFX-2.5/NOPB require an external feedback resistor network?
No. The LM3671MFX-2.5/NOPB is a fixed-output variant with internal resistor divider configured for 2.5 V. The FB pin connects directly to an internal 0.5 V reference, eliminating the need for external resistors. This simplifies layout, improves output voltage accuracy, and removes resistor tolerance and temperature drift effects from the LM3671MFX-2.5/NOPB regulation loop.
What thermal derating applies to LM3671MFX-2.5/NOPB at 85°C ambient?
At 85°C ambient temperature on a 4-layer PCB, the LM3671MFX-2.5/NOPB's maximum power dissipation is 242 mW (per RθJA = 174.7°C/W). This corresponds to approximately 400 mA continuous output current at 2.5 V with 3.6 V input. For sustained 600 mA operation, ambient must be ≤60°C or board-level thermal management (e.g., copper pour, airflow) must be enhanced to maintain junction temperature below 125°C for the LM3671MFX-2.5/NOPB.
Can LM3671MFX-2.5/NOPB operate from a 2.5 V input?
No. The absolute minimum input voltage for LM3671MFX-2.5/NOPB is 2.7 V per the Recommended Operating Conditions table. At 2.5 V input, the device will not regulate - undervoltage lockout disables switching, and output drops to near-zero. This ensures reliable startup only after Li-Ion battery reaches safe operating voltage, protecting downstream circuits powered by the LM3671MFX-2.5/NOPB.
Is LM3671MFX-2.5/NOPB qualified for automotive applications?
No. The LM3671MFX-2.5/NOPB is the commercial-grade variant. Automotive qualification is exclusive to the LM3671-Q1 family (e.g., LM3671QMF-2.5/NOPB), which undergoes AEC-Q100 Grade 1 stress testing (−40°C to +125°C ambient) and includes enhanced ESD robustness on corner pins. For automotive infotainment or body electronics, the LM3671-Q1 version must be specified instead of the LM3671MFX-2.5/NOPB.
LM3671MFX-2.5/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- SC-74A, SOT-753
- 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):
- 2.7V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 2.5V
- Voltage - Output (Max):
- -
- Current - Output:
- 600mA
- Frequency - Switching:
- 2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
LM3671MFX-2.5/NOPB FAQ
1.How can I place an order for LM3671MFX-2.5/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3671MFX-2.5/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 LM3671MFX-2.5/NOPB reliable?
The price and inventory of LM3671MFX-2.5/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3671MFX-2.5/NOPB is usually 5 days.
3.What payment methods are accepted for LM3671MFX-2.5/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3671MFX-2.5/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3671MFX-2.5/NOPB?
LM3671MFX-2.5/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3671MFX-2.5/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 LM3671MFX-2.5/NOPB?
For technical support, including LM3671MFX-2.5/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3671MFX-2.5/NOPB requirements.
6.How does Aetrix verify that LM3671MFX-2.5/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3671MFX-2.5/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 LM3671MFX-2.5/NOPB meets industry standards.
7.What is the process for return or replacement of LM3671MFX-2.5/NOPB?
All LM3671MFX-2.5/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3671MFX-2.5/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 LM3671MFX-2.5/NOPB part is unused and in its original packaging.
Return procedure for LM3671MFX-2.5/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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