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Texas Instruments LM3671LC-1.2/NOPB
- Part No.:
- LM3671LC-1.2/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 6-UFDFN
- Datasheet:
-
LM3671LC-1.2/NOPB.pdf
- Description:
- IC REG BUCK 1.2V 600MA 6USON
- Quantity:
- Payment:
- Shipping:
Inventory:1,249
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Product details
Overview
LM3671LC-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 digital cameras.
For engineers reviewing the LM3671LC-1.2/NOPB datasheet, LM3671LC-1.2/NOPB pinout, LM3671LC-1.2/NOPB application, or LM3671LC-1.2/NOPB equivalent, key selection criteria include its USON-6 package footprint, internal 0.5 V reference with ±4% feedback voltage tolerance, 380 mΩ PFET/250 mΩ NFET RDS(ON), 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 LM3671LC-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 power stage enables synchronous rectification, eliminating external diode losses and supporting >90% peak efficiency at 300 mA output with 3.6 V input.
Functional mode transitions are fully autonomous: PWM mode ensures low-noise, constant-frequency regulation above ~80 mA; PFM mode reduces switching frequency and quiescent current to 16 µA (typ) under light loads; shutdown mode draws just 0.01 µA (typ) when EN < 0.4 V. Soft-start limits inrush current via stepped current-limit ramp (70 → 140 → 280 → 1020 mA).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 1.2 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 instrumentation without external current boosting |
| Input Voltage Range | 2.7 V to 5.5 V - compatible with single-cell Li-ion (2.7–4.2 V) and USB-powered 5 V rails |
| Switching Frequency | 2 MHz (typ), 1.6–2.6 MHz (min/max over temp) - enables use of ultra-small 2.2 µH inductors and 10 µF ceramic output capacitors |
| Quiescent Current | 16 µA (typ) in PFM mode - extends battery runtime during standby/sleep states in always-on sensors and IoT edge nodes |
| Shutdown Current | 0.01 µA (typ) - critical for zero-power retention in battery-backed real-time clocks and secure boot circuits |
| Thermal Shutdown | Engages at 150°C (typ), disengages at 130°C (typ) - protects against sustained overload or poor PCB thermal design |
Pinout & Package
LM3671LC-1.2/NOPB uses the 6-pin USON (NKH) package: 2.00 mm × 2.00 mm body, 0.5 mm pitch, wettable flank terminals. Thermal performance: RθJA = 174.7°C/W (4-layer board).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pin 1) | Power Input | Connects to input filter capacitor; accepts 2.7–5.5 V; supplies internal bias and power switches |
| GND (Pin 2) | Power Ground | Main return path for high-current PFET/NFET switching; must be low-impedance connection to PCB ground plane |
| EN (Pin 3) | Digital Enable | Active-high logic control: device enabled when >1 V, shutdown when <0.4 V; must not float |
| FB (Pin 4) | Feedback Input | Internally tied to 0.5 V reference for fixed 1.2 V output; no external resistors needed |
| SW (Pin 5) | Switch Node | Connection to internal PFET drain and NFET source; drives external inductor; high dv/dt node requiring tight layout |
| SGND (Pin 6) | Signal Ground | Separate analog ground for FB reference; must connect to GND near device but avoid noisy power return paths |
Key Features
| Feature | Design Value |
|---|---|
| Synchronous Rectification | Integrated NFET replaces Schottky diode - eliminates 0.3–0.5 V forward drop, enabling >92% efficiency at 1.2 V/300 mA |
| Auto PFM-PWM Transition | No external control required - seamless switch at ~80 mA load to minimize IQ without compromising transient response |
| Internal Soft Start | Four-step current limit ramp (70→140→280→1020 mA) prevents input rail collapse during cold start into large output capacitance |
| Overcurrent & Thermal Protection | Current limit trips at 1020 mA (open-loop), thermal shutdown engages at 150°C - safeguards IC and PCB under fault conditions |
| Minimal External Components | Only L (2.2 µH), CIN (4.7 µF), COUT (10 µF) required - reduces BOM count, board area, and assembly cost |
Applications
| Mobile Phone Core Rail | Digital Still Camera Sensor Supply |
|---|---|
|
Use Scenario: Powering ARM Cortex-A series application processor cores requiring tightly regulated 1.2 V at up to 500 mA during burst processing. IC Role / Device Role / Timing Role: Primary buck regulator delivering stable core voltage; maintains regulation during rapid CPU frequency scaling and dynamic voltage/frequency scaling (DVFS) transitions. Use Value: 2 MHz switching avoids audible noise in speaker/audio subsystems while enabling fast transient response (<10 µs recovery from 100→500 mA step) to prevent processor brownouts. |
Use Scenario: Supplying CMOS image sensor analog front-end (AFE) and digital interface blocks in compact digital cameras. IC Role / Device Role / Timing Role: Fixed 1.2 V supply for sensor pixel array bias and ADC reference; operates in PFM mode during preview/idle to maximize battery life. Use Value: 16 µA quiescent current extends standby time between shots; USON-6 footprint fits within tight camera module height constraints (<0.55 mm profile). |
| Portable Medical Pulse Oximeter | Handheld Transaction Terminal |
|
Use Scenario: Providing clean, low-noise 1.2 V rail for optical sensor signal conditioning and microcontroller in battery-operated oximeters. IC Role / Device Role / Timing Role: Low-EMI power source for precision analog circuitry; synchronous operation eliminates diode reverse-recovery noise that could corrupt weak photodiode signals. Use Value: Internal soft-start prevents voltage overshoot on 10 µF output cap, ensuring safe startup of sensitive analog front-end without latch-up risk. |
Use Scenario: Powering secure element, NFC controller, and display driver in handheld payment terminals operating from replaceable Li-ion batteries. IC Role / Device Role / Timing Role: Main system regulator supporting deep-sleep modes with sub-µA shutdown current and fast wake-up capability. Use Value: 0.01 µA shutdown current preserves battery charge for >1 year in storage; EN pin allows host MCU to orchestrate full system power sequencing. |
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 1.2 V, 600 mA, 3–6 MHz adjustable frequency, 17 µA IQ, SOT-23-6 package (2.9 × 1.6 mm) | Larger footprint; higher EMI due to variable frequency; requires external compensation | Select when board space allows larger package and design requires frequency tuning to avoid RF bands |
| AP63202WU-7 | Fixed 1.2 V, 2 A, 2.2 MHz, 25 µA IQ, WLCSP-6 (1.5 × 1.5 mm), no SGND pin | Higher current capability; smaller footprint; lacks dedicated signal ground - may impact noise-sensitive analog loads | Select when future-proofing for higher load or space-constrained layouts where analog noise immunity is secondary |
Compared with LM3671LC-1.2/NOPB, TPS62231DRYR offers frequency flexibility at the cost of larger size and added design complexity, while AP63202WU-7 trades SGND isolation for higher current and smaller area - making LM3671LC-1.2/NOPB optimal for noise-critical, space-constrained 600 mA applications where proven thermal reliability and minimal external parts are prioritized.
Availability
LM3671LC-1.2/NOPB is available at Aetrix Electronics and suitable for mobile phones, digital still cameras, and portable medical equipment requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.
Supply support for LM3671LC-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 specializing in analog and embedded processing technologies, with decades of expertise in power management IC design and automotive-grade qualification.
The LM3671 product line was engineered specifically for ultra-portable battery-powered systems demanding high efficiency, minimal external components, and robust protection - targeting smartphones, PDAs, and portable instrumentation where size, battery life, and reliability are non-negotiable.
FAQ
What is the recommended input capacitor for LM3671LC-1.2/NOPB?
The LM3671LC-1.2/NOPB datasheet specifies a 4.7 µF ceramic input capacitor (CIN) placed close to the VIN and GND pins. This value provides sufficient high-frequency decoupling for the 2 MHz switching frequency and limits input voltage ripple to <1% of VIN under 600 mA load transients. X5R or X7R dielectrics with 6.3 V rating are recommended for stability across temperature and bias.
Does LM3671LC-1.2/NOPB require an external feedback resistor network?
No. The LM3671LC-1.2/NOPB is a fixed-output variant with internal resistor divider connecting the FB pin to a precise 0.5 V reference. Unlike the adjustable LM3671-ADJ version, it does not require external R1/R2 resistors - simplifying layout and eliminating resistor tolerance errors that affect output accuracy. The FB pin must remain unconnected externally.
How does thermal performance differ between LM3671LC-1.2/NOPB's USON-6 and SOT-23 packages?
The LM3671LC-1.2/NOPB is only offered in the 6-pin USON (NKH) package, not SOT-23. Its RθJA is 174.7°C/W on a 4-layer board - higher than the SOT-23 variant's 165.7°C/W due to smaller thermal pad area. Effective thermal design requires soldering the exposed thermal pad to a solid copper pour connected to internal ground planes via ≥4 thermal vias.
Can LM3671LC-1.2/NOPB operate with a 2.5 V input voltage?
No. The LM3671LC-1.2/NOPB has a minimum recommended input voltage of 2.7 V per the datasheet's Recommended Operating Conditions. At 2.5 V, the internal PFET may not fully enhance, causing excessive conduction loss, thermal stress, and potential dropout - especially under 300+ mA loads. Operation below 2.7 V voids guaranteed specifications and risks premature failure.
What protection features are integrated into LM3671LC-1.2/NOPB?
The LM3671LC-1.2/NOPB integrates four hardware protections: (1) cycle-by-cycle current limiting (1020 mA typical trip), (2) thermal shutdown (150°C engage / 130°C release), (3) undervoltage lockout (UVLO disables operation below ~2.5 V), and (4) short-circuit foldback in timed current-limit mode. These operate autonomously without software or external components.
LM3671LC-1.2/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 6-UFDFN
- 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:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 6-USON (2x2)
LM3671LC-1.2/NOPB FAQ
1.How can I place an order for LM3671LC-1.2/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3671LC-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 LM3671LC-1.2/NOPB reliable?
The price and inventory of LM3671LC-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 LM3671LC-1.2/NOPB is usually 5 days.
3.What payment methods are accepted for LM3671LC-1.2/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3671LC-1.2/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3671LC-1.2/NOPB?
LM3671LC-1.2/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3671LC-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 LM3671LC-1.2/NOPB?
For technical support, including LM3671LC-1.2/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3671LC-1.2/NOPB requirements.
6.How does Aetrix verify that LM3671LC-1.2/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3671LC-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 LM3671LC-1.2/NOPB meets industry standards.
7.What is the process for return or replacement of LM3671LC-1.2/NOPB?
All LM3671LC-1.2/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3671LC-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 LM3671LC-1.2/NOPB part is unused and in its original packaging.
Return procedure for LM3671LC-1.2/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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