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Texas Instruments LM3674MF-1.2/NOPB
- Part No.:
- LM3674MF-1.2/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LM3674MF-1.2/NOPB.pdf
- Description:
- IC REG BUCK 1.2V 600MA SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:6,293
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Product details
Overview
LM3674MF-1.2/NOPB from Texas Instruments is a fixed-output 1.2 V, 2-MHz synchronous step-down DC-DC converter optimized for single Li-Ion battery-powered portable systems. It delivers up to 600 mA load current across 2.7 V–5.5 V input range, features internal soft-start and 0.01 µA shutdown current, and operates in SOT-23-5 package with only three external components: 2.2 µH inductor, 4.7 µF input capacitor, and 10 µF output capacitor.
For engineers reviewing the LM3674MF-1.2/NOPB datasheet, LM3674MF-1.2/NOPB pinout, LM3674MF-1.2/NOPB application, or LM3674MF-1.2/NOPB equivalent, key selection criteria include its fixed 1.2 V output, 2 MHz switching frequency enabling compact filtering, synchronous rectification for >90% efficiency at mid-load, thermal/overcurrent protection, and compatibility with low-ESR ceramic capacitors in space-constrained mobile designs.
Technical Context
The LM3674MF-1.2/NOPB uses voltage-mode PWM control with input voltage feed-forward to achieve tight line regulation (0.083 %/V) and load regulation (0.0010 %/mA). Its internal 0.5 V reference and fixed resistor divider enable precise 1.2 V output without external feedback components.
It integrates a 380 mΩ PFET high-side switch and 250 mΩ NFET synchronous rectifier, enabling high efficiency across 10 mA–600 mA loads. Protection includes cycle-by-cycle current limiting (1020 mA typical), thermal shutdown, and undervoltage lockout-ensuring robust operation in battery-voltage droop scenarios.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 1.2 V ±4% - eliminates need for external feedback resistors and simplifies layout. |
| Switching Frequency | 2 MHz typical - enables use of small 2.2 µH inductor and 10 µF ceramic output capacitor. |
| Max Load Current | 600 mA - sufficient for core logic rails in smartphones, PDAs, and digital cameras. |
| Input Voltage Range | 2.7 V to 5.5 V - supports full discharge curve of single Li-Ion cell (3.0 V–4.2 V nominal). |
| Shutdown Current | 0.01 µA typical - minimizes battery drain during system sleep modes. |
| Internal Reference | 0.5 V - sets feedback threshold; enables accurate output regulation independent of temperature (−30°C to 125°C). |
| Thermal Protection | Junction shutdown at 125°C - prevents damage during sustained overload or poor PCB thermal design. |
Pinout & Package
LM3674MF-1.2/NOPB is housed in a 5-pin SOT-23 (DBV) package measuring 2.90 mm × 1.60 mm, with exposed pad for thermal enhancement. Pin 1 is VIN; Pin 2 is GND; Pin 3 is EN; Pin 4 is FB; Pin 5 is SW. The package is RoHS-compliant and lead-free (NOPB suffix).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pin 1) | Power input | Accepts 2.7–5.5 V supply; requires local 4.7 µF ceramic decoupling capacitor placed adjacent to pin. |
| GND (Pin 2) | Ground reference | Primary return path for input/output currents and IC substrate; must connect to low-impedance ground plane. |
| EN (Pin 3) | Enable control | Logic-high (>1 V) enables regulation; logic-low (<0.4 V) forces 0.01 µA shutdown; must not float. |
| FB (Pin 4) | Feedback input | Internally connected to fixed 1.2 V divider; monitors output via direct connection to COUT; no external resistors needed. |
| SW (Pin 5) | Switching node | Drives external 2.2 µH inductor; carries high di/dt square wave; requires short, low-inductance trace to L1. |
Key Features
| Feature | Design Value |
|---|---|
| Synchronous rectification | Integrated 250 mΩ NFET replaces external Schottky diode, improving efficiency by 8–12% at 300 mA vs asynchronous designs. |
| Internal soft-start | Staged current limit (70/140/280/1020 mA) prevents inrush into large output capacitors; start-up time ~240–350 µs with 10 µF COUT. |
| 2-MHz fixed-frequency PWM | Enables ultra-compact BOM: eliminates need for large inductors or electrolytic capacitors; reduces EMI filter complexity. |
| Current & thermal protection | Auto-recovering overcurrent limit (1020 mA typ) and thermal shutdown (125°C) protect IC and system under fault conditions. |
| Low quiescent current | 300 µA typical DC bias current in active mode ensures minimal impact on battery runtime during light-load operation. |
Applications
| Mobile Phone Core Rail | Portable Digital Camera Sensor Supply |
|---|---|
Use Scenario: Powering ARM Cortex-A series application processor cores requiring stable 1.2 V at up to 500 mA during burst processing. IC Role / Device Role / Timing Role: Primary buck regulator delivering regulated 1.2 V from single-cell Li-Ion battery; provides clean, low-noise supply with fast transient response. Use Value: 2 MHz switching enables <100 ns load-step response and <25 mV output ripple, preventing core voltage collapse during CPU frequency scaling. | Use Scenario: Supplying image sensor analog front-end (AFE) and ISP logic in compact digital still cameras. IC Role / Device Role / Timing Role: Fixed-output DC-DC converter generating 1.2 V rail from shared battery bus; operates alongside 2.8 V and 3.3 V regulators in multi-rail PMIC subsystem. Use Value: Internal synchronous FETs and 0.5 V reference ensure ±1.5% output accuracy over −30°C to 85°C ambient, critical for low-noise image capture. |
| PDA Application Processor Rail | MP3 Player DSP Core Supply |
Use Scenario: Delivering 1.2 V to OMAP or i.MX application processors in handheld PDAs with limited PCB area. IC Role / Device Role / Timing Role: Compact, high-efficiency step-down converter replacing linear regulators to extend battery life; integrated EN pin enables software-controlled power gating. Use Value: 600 mA capability and 0.01 µA shutdown current allow full system suspend/resume cycles without compromising runtime or wake latency. | Use Scenario: Powering 1.2 V DSP core in portable audio players during decode and playback, where thermal dissipation is constrained by plastic enclosure. IC Role / Device Role / Timing Role: Thermally robust buck converter with junction shutdown and low RDS(on) switches, operating continuously at 400 mA in sealed environments. Use Value: 130 °C/W thermal resistance (4-layer board) and internal thermal protection prevent thermal runaway, ensuring reliable operation at 85°C ambient. |
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 output, 3-MHz switching, 600 mA, but uses different pinout (VIN/GND/EN/PHASE/FB) and lacks internal soft-start ramp. | Requires external soft-start capacitor; higher frequency allows smaller inductor but increases gate-drive losses. | Prefer when board layout prioritizes smallest possible inductor size and system already manages startup sequencing. |
| AP3012KTR-G1 | Fixed 1.2 V, 1.5-MHz, 600 mA, but asynchronous (external diode required); higher dropout and lower efficiency at 300+ mA. | Needs external Schottky diode and larger output capacitor to meet same ripple spec; less suitable for thermally constrained enclosures. | Consider only if cost sensitivity outweighs efficiency and board space requirements. |
Compared with TPS62231DRYR and AP3012KTR-G1, the LM3674MF-1.2/NOPB offers superior thermal performance due to synchronous architecture and lower RDS(on), tighter output accuracy via integrated 0.5 V reference, and simpler implementation with no external soft-start or diode-making it optimal for space- and battery-life-critical portable designs.
Availability
LM3674MF-1.2/NOPB is available at Aetrix Electronics and suitable for mobile phones, portable digital cameras, PDAs, MP3 players, and W-LAN modules requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.
Supply support for LM3674MF-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 company headquartered in Dallas, Texas, designing and manufacturing analog and embedded processing chips for industrial, automotive, and consumer applications.
The LM3674MF-1.2/NOPB belongs to TI's portable power management portfolio, engineered specifically for high-efficiency, low-noise, space-constrained DC-DC conversion in battery-powered handheld devices operating from single Li-Ion cells.
FAQ
What is the recommended input capacitor for LM3674MF-1.2/NOPB?
A 4.7 µF X5R/X7R ceramic capacitor rated for ≥6.3 V is recommended for LM3674MF-1.2/NOPB. It must be placed as close as possible to the VIN and GND pins to minimize high-frequency loop inductance. The minimum acceptable value is 2.2 µF at 3 V DC bias, including tolerances and temperature variation. Avoid Y5V dielectrics due to poor DC bias stability.
Does LM3674MF-1.2/NOPB require external feedback resistors?
No, LM3674MF-1.2/NOPB does not require external feedback resistors. It is a fixed-output variant with internal resistor divider configured for 1.2 V, connecting the FB pin directly to the output capacitor. External resistors are only needed for the adjustable LM3674-ADJ version.
What is the maximum achievable efficiency of LM3674MF-1.2/NOPB at 300 mA load?
LM3674MF-1.2/NOPB achieves up to 93% efficiency at 300 mA load with VIN = 3.6 V, VOUT = 1.2 V, 2.2 µH inductor, and 10 µF ceramic output capacitor. Efficiency drops to ~87% at 10 mA (light load) and ~90% at 600 mA (full load) due to fixed switching losses and conduction losses in internal FETs.
Can LM3674MF-1.2/NOPB operate with an input voltage below 2.7 V?
No, LM3674MF-1.2/NOPB is not guaranteed to operate reliably below 2.7 V. The datasheet specifies 2.7 V as the minimum recommended input voltage; operation below this may cause undervoltage lockout activation or unstable regulation. For sub-2.7 V operation, consider low-dropout alternatives or boost-buck architectures.
How does the EN pin function on LM3674MF-1.2/NOPB?
The EN pin on LM3674MF-1.2/NOPB controls device enable/disable: applying >1 V enables regulation; applying <0.4 V places LM3674MF-1.2/NOPB in shutdown mode with 0.01 µA typical supply current. The pin must never be left floating-tie to GND via 100 kΩ resistor if unused. Internal pull-down is not provided.
LM3674MF-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:
- -30°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
LM3674MF-1.2/NOPB FAQ
1.How can I place an order for LM3674MF-1.2/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3674MF-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 LM3674MF-1.2/NOPB reliable?
The price and inventory of LM3674MF-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 LM3674MF-1.2/NOPB is usually 5 days.
3.What payment methods are accepted for LM3674MF-1.2/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3674MF-1.2/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3674MF-1.2/NOPB?
LM3674MF-1.2/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3674MF-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 LM3674MF-1.2/NOPB?
For technical support, including LM3674MF-1.2/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3674MF-1.2/NOPB requirements.
6.How does Aetrix verify that LM3674MF-1.2/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3674MF-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 LM3674MF-1.2/NOPB meets industry standards.
7.What is the process for return or replacement of LM3674MF-1.2/NOPB?
All LM3674MF-1.2/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3674MF-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 LM3674MF-1.2/NOPB part is unused and in its original packaging.
Return procedure for LM3674MF-1.2/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM3674MF-1.2/NOPB Tags
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TPS562201DDCR
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MC34063ABD-TR
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TPS561201DDCR
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MC33063ADR
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AZ34063UMTR-G1
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