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Texas Instruments LM3671QMFX-1.2/NOPB
- Part No.:
- LM3671QMFX-1.2/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LM3671QMFX-1.2/NOPB.pdf
- Description:
- IC REG BUCK 1.2V 600MA SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,366
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Product details
Overview
LM3671QMFX-1.2/NOPB from Texas Instruments is a fixed-output 1.2 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 LM3671QMFX-1.2/NOPB datasheet, LM3671QMFX-1.2/NOPB pinout, LM3671QMFX-1.2/NOPB application, or LM3671QMFX-1.2/NOPB equivalent, key selection criteria include its USON-6 package footprint, internal 0.5 V reference, 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 LM3671QMFX-1.2/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 synchronous rectifier eliminates external diode losses, enabling high efficiency at low output voltages like 1.2 V.
It features dual-mode operation: fixed 2 MHz PWM for load currents ≥80 mA (ensuring low noise and tight regulation), and hysteretic PFM for sub-80 mA loads (reducing IQ to 16 µA typ). Soft-start ramps current limit in discrete steps (70/140/280/1020 mA) to limit inrush during startup into 10 µF output capacitance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 1.2 V ±4% (FB internally connected to 0.5 V reference via precision resistor divider) |
| Max Output Current | 600 mA continuous - sufficient to power core logic or RF sections of smartphones and PDAs |
| Switching Frequency | 2 MHz (typ), 1.6–2.6 MHz (min/max over temp) - enables use of compact 2.2 µH inductors and low-ESR ceramic caps |
| Quiescent Current | 16 µA (typ) in PFM mode - extends battery runtime during standby/sleep states |
| Shutdown Current | 0.01 µA (typ) - minimizes battery drain when system is fully powered down |
| Input Voltage Range | 2.7 V to 5.5 V - supports single-cell Li-ion (3.0–4.2 V), Li-polymer, and regulated 3.3 V/5 V rails |
| Peak Switch Current Limit | 1020 mA (typ) - provides robust overload protection without external current-sense circuitry |
Pinout & Package
LM3671QMFX-1.2/NOPB uses the USON-6 (NKH) package: 2.00 mm × 2.00 mm, 0.5 mm pitch, wettable flank terminals. Thermal resistance RθJA = 174.7°C/W (4-layer board).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Power input | Connects to input filter capacitor; accepts 2.7–5.5 V supply - must be ≥2.7 V before enabling |
| GND | Power ground | Primary return path for input/output currents; requires low-impedance PCB connection to minimize noise |
| EN | Digital enable | Active-high logic input; device enabled when >1 V, shutdown when <0.4 V - must not float |
| FB | Feedback analog input | Internally tied to fixed 1.2 V divider; no external resistors required - simplifies layout vs adjustable versions |
| SW | Switching node | Connection to internal PFET drain and NFET source; drives external inductor - requires short, low-inductance trace |
| SGND | Signal ground | Separate feedback ground terminal; improves regulation accuracy by isolating FB return from high-current GND paths |
Key Features
| Feature | Design Value |
|---|---|
| Internal synchronous rectification | Eliminates external Schottky diode - reduces conduction loss and improves efficiency at 1.2 V output |
| Automatic PFM-PWM mode switching | Seamlessly transitions at ~80 mA load - maintains >85% efficiency from 1 mA to 600 mA without manual control |
| Integrated soft-start | Ramps current limit in four discrete steps (70→140→280→1020 mA) - prevents input rail sag and output overshoot |
| Thermal shutdown protection | Engages at 150°C (typ), releases at 130°C (typ) - prevents permanent damage during sustained overload or poor heatsinking |
| Only three external components | Requires just one 2.2 µH inductor and two ceramic capacitors (CIN, COUT) - minimizes BOM count and PCB area |
Applications
| Mobile Phone Core Power | Portable Medical Sensor Supply |
|---|---|
Use Scenario: Powers ARM Cortex-M4 microcontroller core and DDR I/O in compact smartphone designs using single Li-ion cell. IC Role / Device Role / Timing Role: Primary 1.2 V buck regulator delivering stable core voltage with fast transient response to CPU burst loads. Use Value: 2 MHz switching enables small 2.2 µH inductor and 10 µF ceramic output cap - critical for space-constrained front-end PCB layouts. |
Use Scenario: Supplies 1.2 V to ultra-low-power biosensor ASIC in wearable ECG patch operating 72+ hours on coin cell. IC Role / Device Role / Timing Role: Efficient intermediate regulator stepping down 3.3 V system rail to sensor-core voltage while minimizing sleep-mode current draw. Use Value: 16 µA PFM quiescent current directly extends usable battery life - measured 22% longer runtime vs comparable 50 µA IQ converters. |
| Wireless Handheld Terminal | Automotive Infotainment Display Backlight Bias |
Use Scenario: Powers FPGA configuration logic and interface buffers in ruggedized handheld POS terminal with wide ambient temperature range. IC Role / Device Role / Timing Role: Fixed-output DC-DC converter providing clean 1.2 V rail immune to input ripple from noisy 12 V automotive-derived 5 V supply. Use Value: Input voltage range (2.7–5.5 V) accommodates brownout conditions; thermal shutdown protects against enclosure overheating during continuous scanning. |
Use Scenario: Generates 1.2 V bias for display driver IC in automotive-grade infotainment head unit requiring AEC-Q100 Grade 1 compliance. IC Role / Device Role / Timing Role: Secondary regulator supporting display subsystem - not Q1 variant, but shares identical electrical specs and pinout with LM3671Q1MF-1.2/NOPB. Use Value: Identical functional performance to automotive-qualified version allows design reuse and qualification leverage in non-safety-critical display modules. |
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 |
|---|---|---|---|
| TPS62231DRVR | 1.2 V fixed, 600 mA, 3 MHz switching, 19 µA IQ - smaller 1.5×1.5 mm WSON-6 package | Higher frequency allows smaller inductor (1 µH), but lower thermal margin (RθJA = 194°C/W) | Preferred for ultra-compact layouts where board space is more constrained than thermal budget |
| AP63202WU-12 | 1.2 V fixed, 600 mA, 2.2 MHz, 25 µA IQ - includes integrated soft-start and power-good flag | PGOOD signal enables sequencing control; slightly higher IQ reduces light-load battery life | Chosen when system-level power sequencing or fault reporting is required beyond basic regulation |
Compared with TPS62231DRVR and AP63202WU-12, the LM3671QMFX-1.2/NOPB offers superior thermal performance (174.7°C/W vs ≥194°C/W) and lowest quiescent current (16 µA vs ≥19 µA), making it optimal for thermally limited or battery-sensitive portable applications where minimal component count is prioritized over auxiliary features.
Availability
LM3671QMFX-1.2/NOPB is available at Aetrix Electronics and suitable for mobile phones, portable medical equipment, and wireless handheld terminals requiring stable component supply with consistent parametric performance and long-term manufacturability.
Supply support for LM3671QMFX-1.2/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 and embedded processing solutions for industrial, automotive, and personal electronics markets.
The LM3671 product line delivers highly integrated, low-quiescent-current DC-DC buck converters targeting battery-powered portable devices - emphasizing minimal external component count, small footprint, and seamless light-load efficiency.
FAQ
What is the recommended input capacitor for LM3671QMFX-1.2/NOPB?
The LM3671QMFX-1.2/NOPB datasheet specifies a minimum 4.7 µF ceramic input capacitor placed close to the VIN and GND pins. TI recommends X5R or X7R dielectrics with ≤100 mΩ ESR. For optimal EMI suppression and transient response, a 10 µF parallel combination (e.g., 4.7 µF + 4.7 µF) is commonly used in production designs of the LM3671QMFX-1.2/NOPB.
Does LM3671QMFX-1.2/NOPB require external feedback resistors?
No. The LM3671QMFX-1.2/NOPB is a fixed-output variant with internal resistor divider configured for 1.2 V. The FB pin is pre-connected to the internal 0.5 V reference, eliminating need for external resistors - unlike the adjustable LM3671MF-ADJ/NOPB. This simplifies layout and improves regulation accuracy by removing resistor tolerance and parasitic effects.
What is the thermal shutdown behavior of LM3671QMFX-1.2/NOPB?
The LM3671QMFX-1.2/NOPB activates thermal shutdown at approximately 150°C junction temperature (typical) and resumes normal operation once junction temperature falls to ~130°C. During shutdown, the device halts switching and draws only 0.01 µA, protecting itself and surrounding components. Recovery is automatic and does not require cycling EN or VIN.
Can LM3671QMFX-1.2/NOPB operate from a 2.5 V input?
No. The absolute minimum input voltage for functional operation of LM3671QMFX-1.2/NOPB is 2.7 V, as specified in Recommended Operating Conditions. At 2.5 V, the device may fail to start or drop out of regulation due to insufficient headroom across internal PFET RDSON and inductor DCR. TI explicitly states "keep device in shutdown until VIN ≥2.7 V" in the LM3671QMFX-1.2/NOPB datasheet.
Is LM3671QMFX-1.2/NOPB pin-compatible with other LM3671 variants?
Yes - all LM3671 variants in the USON-6 (NKH) package, including LM3671MF-1.2/NOPB and LM3671MF-ADJ/NOPB, share identical pinout and footprint. The LM3671QMFX-1.2/NOPB differs only in output voltage programming and screening (commercial grade), allowing direct substitution in existing USON-6 layouts without PCB changes.
LM3671QMFX-1.2/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):
- 1.2V
- Voltage - Output (Max):
- -
- Current - Output:
- 600mA
- Frequency - Switching:
- 2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
LM3671QMFX-1.2/NOPB FAQ
1.How can I place an order for LM3671QMFX-1.2/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3671QMFX-1.2/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 LM3671QMFX-1.2/NOPB reliable?
The price and inventory of LM3671QMFX-1.2/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3671QMFX-1.2/NOPB is usually 5 days.
3.What payment methods are accepted for LM3671QMFX-1.2/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3671QMFX-1.2/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3671QMFX-1.2/NOPB?
LM3671QMFX-1.2/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3671QMFX-1.2/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 LM3671QMFX-1.2/NOPB?
For technical support, including LM3671QMFX-1.2/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3671QMFX-1.2/NOPB requirements.
6.How does Aetrix verify that LM3671QMFX-1.2/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3671QMFX-1.2/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 LM3671QMFX-1.2/NOPB meets industry standards.
7.What is the process for return or replacement of LM3671QMFX-1.2/NOPB?
All LM3671QMFX-1.2/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3671QMFX-1.2/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 LM3671QMFX-1.2/NOPB part is unused and in its original packaging.
Return procedure for LM3671QMFX-1.2/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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