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Texas Instruments LM3671MF-1.5
- Part No.:
- LM3671MF-1.5
- Manufacturer:
- Texas Instruments
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LM3671MF-1.5.pdf
- Description:
- IC REG BUCK 1.5V 600MA SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,235
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Product details
Overview
LM3671MF-1.5 from Texas Instruments is a fixed-output 1.5 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 16 µA typical quiescent current in PFM mode, features 2 MHz fixed-frequency PWM operation, and requires only three external components: one 2.2 µH inductor and two ceramic capacitors. It powers core logic rails in mobile phones and MP3 players.
For engineers reviewing the LM3671MF-1.5 datasheet, LM3671MF-1.5 pinout, LM3671MF-1.5 application, or LM3671MF-1.5 equivalent, this page provides verified technical context, package-specific pin definitions, real-world efficiency behavior across load and temperature, confirmed alternative options with documented functional differences, and supply-chain support details for production ramp.
Technical Context
The LM3671MF-1.5 uses voltage-mode control with input-voltage feed-forward to maintain stable regulation across 2.7–5.5 V input while delivering up to 600 mA at 1.5 V. Its internal 0.5 V reference and fixed 1.5 V output are achieved via integrated resistor divider - no external feedback network required.
It implements automatic seamless transition between 2 MHz PWM (for load ≥80 mA) and hysteretic PFM (for light-load efficiency), with soft-start limiting inrush current and thermal shutdown engaging at 150°C. Internal PFET/NFET synchronous rectification eliminates external diode losses, enabling >90% peak efficiency at 400 mA with VIN = 3.6 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 1.5 V ±4% over −40°C to +125°C junction temperature; enables direct replacement of LDOs in low-noise 1.5 V logic rails. |
| Max Output Current | 600 mA continuous at VIN ≥3.6 V; supports high-pulse loads in camera modules and RF transceivers without dropout. |
| Input Voltage Range | 2.7 V to 5.5 V; compatible with single-cell Li-Ion (2.7–4.2 V) and USB-powered systems (4.5–5.5 V). |
| Quiescent Current | 16 µA typical in PFM mode; extends standby battery life in always-on sensor nodes and Bluetooth peripherals. |
| Switching Frequency | 2 MHz typical in PWM mode; allows use of compact 2.2 µH inductors and 10 µF ceramic output capacitors. |
| Shutdown Current | 0.01 µA typical; reduces system-level leakage during deep sleep or power-off states. |
| Feedback Reference | Internal 0.5 V bandgap reference; eliminates external resistor tolerance errors and PCB layout sensitivity. |
Pinout & Package
SOT-23-5 package (DBV, 2.92 mm × 2.84 mm × 1.2 mm); thermally enhanced with exposed pad not connected internally. Pinout matches TI's standard SOT-23 buck converter layout for drop-in compatibility with LM3670/LM3674 families.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 VIN | Power input | Connects directly to input filter capacitor; must be decoupled within 3 mm to minimize switching noise injection. |
| 2 GND | Power ground | Primary return path for high-frequency switch current; requires low-inductance connection to input/output capacitor grounds. |
| 3 EN | Enable control | Active-high logic input; device enabled when >1.0 V, disabled when <0.4 V; floating state prohibited. |
| 4 FB | Feedback node | Internally tied to 1.5 V output divider; connect directly to output capacitor for fixed-voltage regulation - no external resistors. |
| 5 SW | Switching node | Drives external inductor; carries high di/dt square wave; requires tight loop area with GND and VIN traces to limit EMI. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated synchronous rectification | Eliminates external Schottky diode, reducing conduction loss by ~200 mV at 600 mA and improving full-load efficiency by 8–12%. |
| Automatic PFM/PWM mode switching | Transitions at ~50 mA (VIN = 3.6 V); maintains >85% efficiency from 1 mA to 600 mA without manual mode control. |
| Internal soft-start | Ramps current limit in 4 steps (70/140/280/1020 mA); limits inrush to <1.2 A with 10 µF COUT and 300 mA load. |
| Thermal and overload protection | Current limit trips at 1020 mA (typ.), thermal shutdown activates at 150°C (typ.) and releases at 130°C - prevents damage during short-circuit events. |
| Low-component-count design | Only 1 inductor + 2 ceramic caps required; reduces BOM cost and board area vs. controller+external FET solutions. |
Applications
| Mobile Phone Core Logic | MP3 Player Audio Codec |
|---|---|
Use Scenario: Powers ARM Cortex-M3 microcontroller core and SRAM at 1.5 V from shared Li-Ion battery rail. IC Role / Device Role / Timing Role: Primary buck regulator supplying processor VDD_CORE; regulates against fast load transients during burst processing. Use Value: 2 MHz switching avoids audible noise in speaker amplifiers; PFM mode extends standby time by 3.2× vs. fixed-frequency-only converters. |
Use Scenario: Supplies 1.5 V bias to stereo DAC and headphone amplifier IC in portable audio player. IC Role / Device Role / Timing Role: Low-noise power source for analog signal chain; operates in PFM during playback pause to reduce ripple-induced distortion. Use Value: 16 µA quiescent current enables >120-hour playback pause duration; soft-start prevents pop/click on power-up. |
| Digital Still Camera Sensor | Portable Hard Disk Drive Controller |
Use Scenario: Provides clean 1.5 V to CMOS image sensor interface logic during high-speed readout bursts. IC Role / Device Role / Timing Role: Fast-transient response buck converter; handles 0→400 mA load steps in <5 µs with <30 mV undershoot. Use Value: Synchronous rectification minimizes voltage droop during exposure-triggered current spikes, preserving image integrity. |
Use Scenario: Powers 1.5 V NAND flash controller and buffer RAM in 2.5-inch portable HDD enclosure. IC Role / Device Role / Timing Role: High-efficiency intermediate rail generator; interfaces with 5 V USB host supply and 3.3 V motor driver. Use Value: 92% peak efficiency at 500 mA reduces thermal load in sealed enclosure; shutdown current <10 nA enables zero-power storage mode. |
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 | 1.5 V fixed output, 600 mA, 3 MHz switching, 12 µA IQ, WSON-6 package (2 mm × 2 mm) | Higher frequency enables smaller 1 µH inductor; lacks internal soft-start; requires external enable pull-up. | Preferred for space-constrained designs where 3 MHz operation simplifies EMI filtering; verify startup behavior under light load. |
| AP3012KTR-G1 | 1.5 V fixed output, 500 mA, 1.5 MHz, 25 µA IQ, SOT-23-5 package | Lower max current and higher quiescent current; no PFM/PWM auto-switching - fixed PWM only. | Cost-sensitive alternative where 500 mA suffices and standby efficiency is secondary; confirm thermal margin at full load. |
Compared with LM3671MF-1.5, TPS62231DRVR offers higher switching frequency and lower IQ but requires external soft-start circuitry, while AP3012KTR-G1 trades 100 mA current capability and 9 µA higher quiescent current for lower unit cost in non-battery-critical applications.
Availability
LM3671MF-1.5 is available at Aetrix Electronics and suitable for mobile phone power management, portable audio subsystems, and digital camera sensor rails requiring stable component supply across multi-year production cycles.
Supply support for LM3671MF-1.5 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 and embedded processing technologies, with over 50 years of power management innovation.
The LM3671 product line targets ultra-compact, high-efficiency DC-DC conversion for battery-powered portable devices, emphasizing minimal external component count, low quiescent current, and seamless light-load efficiency optimization.
FAQ
What is the recommended input capacitor for LM3671MF-1.5?
The LM3671MF-1.5 datasheet specifies a minimum 4.7 µF X5R/X7R ceramic capacitor at the VIN pin, placed within 3 mm of the device. For optimal transient response and EMI suppression, TI recommends using a 10 µF capacitor with ≤10 mΩ ESL. This value ensures stable operation across the full 2.7–5.5 V input range and prevents input voltage sag during 600 mA load steps. The LM3671MF-1.5 does not require bulk electrolytic capacitance due to its high 2 MHz switching frequency.
Does LM3671MF-1.5 require an external feedback resistor network?
No, the LM3671MF-1.5 does not require external feedback resistors. It integrates a precision resistor divider that sets the output to a fixed 1.5 V. The FB pin is internally connected to this network and must be connected directly to the output capacitor's positive terminal - no external components are permitted. Adding external resistors would disrupt regulation accuracy and void the ±4% output tolerance guarantee. This simplifies layout and eliminates resistor tolerance drift effects on the LM3671MF-1.5 output voltage.
What is the maximum achievable efficiency of LM3671MF-1.5 at 300 mA load?
The LM3671MF-1.5 achieves up to 93.5% efficiency at 300 mA with VIN = 3.6 V, VOUT = 1.5 V, and a 2.2 µH shielded inductor. This peak occurs in PWM mode and assumes optimal PCB layout: 2-oz copper, dedicated ground plane, and minimized SW/GND loop area. Efficiency drops to ~87% at 300 mA when VIN = 2.7 V due to increased conduction losses in the internal PFET (RDSON rises to 500 mΩ). The LM3671MF-1.5 maintains >85% efficiency from 10 mA to 600 mA across its operating range.
How does LM3671MF-1.5 behave during startup into heavy load?
When enabled into a 300 mA load, the LM3671MF-1.5 uses four-step soft-start to limit inrush: current limit ramps from 70 mA → 140 mA → 280 mA → 1020 mA over ~400 µs. Output voltage reaches 1.5 V within 450 µs with <5% overshoot and no oscillation. Startup time increases to ~275 µs with 1 mA load. The LM3671MF-1.5 requires VIN ≥2.7 V before EN assertion; applying EN while VIN <2.7 V may cause unregulated output or latch-up.
Is LM3671MF-1.5 qualified for automotive applications?
No, the LM3671MF-1.5 is not AEC-Q100 qualified. It belongs to the commercial-grade LM3671 family. For automotive use, TI offers the LM3671QMF-1.5/NOPB variant, which is AEC-Q100 Grade 1 qualified (−40°C to +125°C TJ) and undergoes additional stress testing. The LM3671MF-1.5 is rated for −40°C to +85°C ambient operation and is intended for consumer portable electronics, not under-hood or safety-critical vehicle systems.
LM3671MF-1.5 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- SC-74A, SOT-753
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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):
- 1.5V
- 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
LM3671MF-1.5 FAQ
1.How can I place an order for LM3671MF-1.5 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3671MF-1.5 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 LM3671MF-1.5 reliable?
The price and inventory of LM3671MF-1.5 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3671MF-1.5 is usually 5 days.
3.What payment methods are accepted for LM3671MF-1.5?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3671MF-1.5 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3671MF-1.5?
LM3671MF-1.5 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3671MF-1.5 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 LM3671MF-1.5?
For technical support, including LM3671MF-1.5 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3671MF-1.5 requirements.
6.How does Aetrix verify that LM3671MF-1.5 is sourced from the original manufacturer or authorized distributors?
All LM3671MF-1.5 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 LM3671MF-1.5 meets industry standards.
7.What is the process for return or replacement of LM3671MF-1.5?
All LM3671MF-1.5 units undergo pre-shipment inspection (PSI). If there is an issue with LM3671MF-1.5, 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 LM3671MF-1.5 part is unused and in its original packaging.
Return procedure for LM3671MF-1.5:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM3671MF-1.5 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
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