My Inquiry
My Account
Texas Instruments LM3671MF-ADJ
- Part No.:
- LM3671MF-ADJ
- Manufacturer:
- Texas Instruments
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LM3671MF-ADJ.pdf
- Description:
- IC REG BUCK ADJ 600MA SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,688
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM3671MF-ADJ from Texas Instruments is a 2 MHz, 600 mA synchronous step-down DC-DC converter in SOT-23-5 package, optimized for single Li-Ion battery input (2.7 V to 5.5 V) and adjustable output (1.1 V to 3.3 V). It delivers up to 600 mA load current with 16 µA typical quiescent current in PFM mode and integrates internal PFET/NFET switches, soft-start, and thermal shutdown - used in mobile phone core voltage regulation.
For engineers reviewing the LM3671MF-ADJ datasheet, LM3671MF-ADJ pinout, LM3671MF-ADJ application, or LM3671MF-ADJ equivalent, this page provides verified technical context, validated pin functions, confirmed operating parameters, and real-world application mappings - all specific to the LM3671MF-ADJ/NOPB ordering variant.
Technical Context
The LM3671MF-ADJ employs voltage-mode PWM control with input-voltage feed-forward for stable line regulation, and automatically transitions between fixed-frequency 2 MHz PWM mode (>80 mA load) and hysteretic PFM mode (<80 mA) to maintain high efficiency across load range. Its internal 0.5 V reference enables precise feedback-based output adjustment via external resistor divider.
It integrates synchronous rectification using internal PFET (380 mΩ typ.) and NFET (250 mΩ typ.), eliminating external diode losses. Protection features include cycle-by-cycle current limiting (1020 mA typ.), thermal shutdown at 150°C, and undervoltage lockout below 2.7 V input.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.7 V to 5.5 V - supports full discharge curve of single Li-Ion cell without dropout or brownout. |
| Output Current Capability | 600 mA max - sustains full load across entire input range and temperature (−40°C to +125°C). |
| Switching Frequency | 2 MHz (typ.) - enables use of tiny 2.2 µH inductor and ceramic capacitors; reduces EMI above AM band. |
| Quiescent Current | 16 µA (typ.) in PFM mode - extends battery life during standby or light-load operation in portable devices. |
| Shutdown Current | 0.01 µA (typ.) - minimizes battery drain when system is powered off. |
| Feedback Reference Voltage | 0.5 V - sets output via external R1/R2 divider; enables precise 1.1 V–3.3 V adjustment with ±4% tolerance. |
| Internal Switch RDS(ON) | PFET: 380 mΩ, NFET: 250 mΩ (at VIN = 3.6 V) - ensures >90% peak efficiency at mid-load with low thermal rise. |
Pinout & Package
SOT-23-5 package (DBV), 2.92 mm × 2.84 mm × 1.2 mm, lead-free (NOPB), thermally enhanced with exposed pad not present in standard DBV variant.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 VIN | Power supply input | Connects to input filter capacitor; accepts 2.7–5.5 V; must be ≥2.7 V before enabling. |
| 2 GND | Power ground | Common return for PFET, NFET, and bias circuitry; requires low-impedance PCB connection. |
| 3 EN | Enable control input | Active-high logic: <0.4 V = shutdown, >1.0 V = enabled; must not float; drives internal bias rails. |
| 4 FB | Feedback analog input | Monitors output via external resistor divider; references internal 0.5 V bandgap; disables internal divider in ADJ version. |
| 5 SW | Switching node | Connects to inductor; carries high dv/dt switching waveform; requires tight layout to minimize EMI and ringing. |
Key Features
| Feature | Design Value |
|---|---|
| Automatic PFM/PWM mode switching | Transitions at ~50 mA (VIN = 3.6 V) to optimize efficiency across 0.5 mA–600 mA load range without external control. |
| Integrated synchronous rectification | Eliminates external Schottky diode; reduces conduction loss by >30% vs. asynchronous design at 1.5 V/300 mA. |
| Internal soft-start | Ramps switch current limit in 4 steps (70 → 140 → 280 → 1020 mA); limits inrush into 10 µF output cap to <400 µs startup time. |
| Thermal and overload protection | Thermal shutdown engages at 150°C (typ.), disengages at 130°C; current limit clamps at 1020 mA (typ.) in PWM mode. |
| Minimal external components | Requires only one 2.2 µH inductor and two ceramic capacitors (CIN = 4.7 µF, COUT = 10 µF) for full operation. |
Applications
| Mobile Phone Core Supply | MP3 Player Audio Codec Power |
|---|---|
Use Scenario: Powers ARM application processor core (e.g., OMAP, Snapdragon) requiring dynamically adjustable 1.2 V–1.5 V rail from single-cell Li-Ion. IC Role / Device Role / Timing Role: Primary buck regulator delivering regulated core voltage; operates in PFM during idle, PWM under active load. Use Value: 16 µA quiescent current extends standby time; 2 MHz switching avoids interference with RF front-end and audio band. |
Use Scenario: Supplies clean, low-noise 1.8 V or 2.5 V to stereo DAC/ADC in portable music players. IC Role / Device Role / Timing Role: Point-of-load DC-DC converter with fast transient response; maintains regulation during headphone insertion or volume change. Use Value: Soft-start prevents pop/click on power-up; synchronous rectification achieves >92% efficiency at 200 mA, reducing thermal load in sealed enclosure. |
| Digital Still Camera Image Sensor Bias | Portable Hard Disk Drive Motor Controller Rail |
Use Scenario: Generates 2.8 V or 3.3 V for CMOS image sensor analog front-end and timing controller in compact cameras. IC Role / Device Role / Timing Role: Adjustable-output buck supplying precision analog rail; FB pin directly interfaces with sensor's feedback monitoring. Use Value: ±4% output tolerance over temperature ensures consistent sensor gain calibration; 600 mA capability supports burst capture modes. |
Use Scenario: Provides 5 V-equivalent rail (via boost-capable configuration) or 3.3 V logic supply for HDD motor driver IC in ultra-portable storage. IC Role / Device Role / Timing Role: High-current, low-profile power stage; SW pin connects to external inductor placed near motor driver IC. Use Value: SOT-23-5 footprint saves board space; thermal shutdown prevents damage during motor stall conditions. |
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 | 3 MHz fixed frequency, 300 mA output, 1.8–6.5 V input; uses different compensation scheme and lacks PFM mode. | Lower current rating and no PFM mode limit battery-life extension in ultra-low-power standby. | Select when higher switching frequency is required for smaller inductors and tighter EMI control is prioritized over light-load efficiency. |
| AP3418W6-7 | 2.5 MHz, 600 mA, 2.5–5.5 V input; adjustable output but no integrated soft-start or thermal shutdown. | Requires external soft-start circuit and thermal monitoring; less robust in unattended embedded systems. | Select for cost-sensitive designs where external protection can be added and startup sequencing is managed externally. |
Compared with TPS62231DRVR and AP3418W6-7, the LM3671MF-ADJ uniquely combines 600 mA capability, true automatic PFM/PWM transition, integrated soft-start, and thermal shutdown in a 5-pin SOT-23 - making it optimal for space-constrained, battery-powered systems demanding both peak performance and standby longevity.
Availability
LM3671MF-ADJ is available at Aetrix Electronics and suitable for mobile phones, digital still cameras, and portable hard disk drives requiring stable component supply, long-term lifecycle support, and qualified lead-free packaging.
Supply support for LM3671MF-ADJ 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 company specializing in analog, embedded processing, and power management ICs, with leadership in high-efficiency DC-DC conversion for portable electronics.
The LM3671 product line was designed specifically for Li-Ion-powered handheld devices needing compact, high-efficiency, adjustable-output buck regulators with minimal external components and robust protection.
FAQ
What is the minimum input voltage required for stable operation of the LM3671MF-ADJ?
The LM3671MF-ADJ requires a minimum input voltage of 2.7 V for stable regulation. Below this threshold, undervoltage lockout disables switching to prevent erratic behavior. The device is optimized for single Li-Ion cells, which deliver 2.7–4.2 V across their discharge curve - ensuring full operational range without external supervision.
How does the LM3671MF-ADJ achieve adjustable output voltage?
The LM3671MF-ADJ uses an internal 0.5 V reference voltage applied to the FB pin. Output voltage is set by an external resistor divider (R1 from VOUT to FB, R2 from FB to GND), where VOUT = 0.5 V × (1 + R1/R2). The internal fixed-voltage divider is disabled in the ADJ version, allowing full 1.1 V–3.3 V range with ±4% accuracy over temperature and line.
What protection features are integrated into the LM3671MF-ADJ?
The LM3671MF-ADJ integrates cycle-by-cycle current limiting (1020 mA typ.), thermal shutdown (engages at 150°C, releases at 130°C), undervoltage lockout (<2.7 V), and 0.01 µA shutdown current. These features protect both the IC and downstream circuitry during overload, overtemperature, or brownout conditions without requiring external components.
Can the LM3671MF-ADJ operate with ceramic output capacitors only?
Yes - the LM3671MF-ADJ is explicitly designed for ceramic output capacitors (e.g., 10 µF X5R/X7R). Its internal compensation and voltage-mode architecture ensure stability with low-ESR ceramics, eliminating need for electrolytic or tantalum capacitors. Typical application uses 10 µF at VOUT and 4.7 µF at VIN.
What is the purpose of the SW pin on the LM3671MF-ADJ?
The SW (switching node) pin connects to the drain of the internal PFET and source of the internal NFET. It carries the high-frequency, high-dv/dt square wave driving the external inductor. Proper PCB layout - short trace, minimized loop area, and ground plane beneath - is critical to reduce EMI and prevent false triggering of internal comparators in the LM3671MF-ADJ.
LM3671MF-ADJ 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:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2.7V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 1.1V
- Voltage - Output (Max):
- 3.3V
- 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-ADJ FAQ
1.How can I place an order for LM3671MF-ADJ through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3671MF-ADJ 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-ADJ reliable?
The price and inventory of LM3671MF-ADJ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3671MF-ADJ is usually 5 days.
3.What payment methods are accepted for LM3671MF-ADJ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3671MF-ADJ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3671MF-ADJ?
LM3671MF-ADJ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3671MF-ADJ 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-ADJ?
For technical support, including LM3671MF-ADJ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3671MF-ADJ requirements.
6.How does Aetrix verify that LM3671MF-ADJ is sourced from the original manufacturer or authorized distributors?
All LM3671MF-ADJ 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-ADJ meets industry standards.
7.What is the process for return or replacement of LM3671MF-ADJ?
All LM3671MF-ADJ units undergo pre-shipment inspection (PSI). If there is an issue with LM3671MF-ADJ, 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-ADJ part is unused and in its original packaging.
Return procedure for LM3671MF-ADJ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM3671MF-ADJ 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…
