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Texas Instruments LM3668SDX-3034/NOPB
- Part No.:
- LM3668SDX-3034/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 12-WFDFN Exposed Pad
- Datasheet:
-
LM3668SDX-3034/NOPB.pdf
- Description:
- IC REG BUCK BOOST PROG 1A 12WSON
- Quantity:
- Payment:
- Shipping:
Inventory:4,015
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Product details
Overview
LM3668SDX-3034/NOPB from Texas Instruments is a synchronous dual-mode buck-boost DC-DC converter delivering 3.0 V or 3.4 V output from 2.5–5.5 V input, supporting up to 1-A load at VIN ≥ 3.9 V, featuring 2.2-MHz fixed-frequency PWM and automatic PFM-PWM mode switching for Li-ion-powered portable electronics.
For engineers reviewing the LM3668SDX-3034/NOPB datasheet, LM3668SDX-3034/NOPB pinout, LM3668SDX-3034/NOPB application, or LM3668SDX-3034/NOPB equivalent, this device is selected for compact, high-efficiency pre-regulation in space-constrained battery-operated systems requiring seamless buck/boost transition and ultra-low quiescent current in standby.
Technical Context
The LM3668SDX-3034/NOPB implements voltage-mode control with four internal MOSFETs (two P-channel, two N-channel) arranged in a single-inductor buck-boost topology that enables continuous conduction across input/output voltage crossovers. Its MODE/SYNC pin selects between automatic PFM-PWM mode (45 µA typical IQ) and forced PWM mode (600–750 µA IQ).
Operation is governed by real-time feedback via the FB pin and VSEL logic level (low = 3.0 V, high = 3.4 V), while internal current limiting (1.85 A typ.) and thermal shutdown (150°C trip) ensure robustness under overload or elevated ambient conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage Options | 3.0 V (VSEL = low) or 3.4 V (VSEL = high); factory-configured dual-output capability per part number |
| Input Voltage Range | 2.5 V to 5.5 V; supports full Li-ion battery discharge curve (3.0–4.2 V) plus USB or wall-adapter inputs |
| Max Output Current | 1 A at VIN ≥ 3.9 V; drops to 800 mA at VIN = 3.4–3.8 V and 700 mA at VIN = 3.0–3.3 V per datasheet Table 1 |
| Switching Frequency | 2.2 MHz typical (PWM mode); enables use of 2.2-µH inductor and small 10-µF/22-µF ceramic capacitors |
| Quiescent Current | 45 µA typical in PFM mode; extends battery runtime during system standby or light-load operation |
| Shutdown Current | 0.01 µA typical; minimizes battery drain when EN pin is pulled low |
| Current Limit Threshold | 1.85 A typical peak switch current; protects internal FETs and external components during overloads |
Pinout & Package
LM3668SDX-3034/NOPB uses a 12-pin WSON (DQB) package measuring 3.00 mm × 3.00 mm with exposed die attach pad (DAP) for thermal enhancement. The DAP must be connected to SGND on PCB for optimal thermal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VOUT | Output voltage node | Connects directly to output capacitor; regulated 3.0 V or 3.4 V depending on VSEL state |
| SW2 | Switching node (P2/N2) | Internal connection to PFET P2 and NFET N2; critical for boost-mode energy transfer |
| PGND | Power ground return | Low-impedance path for high-current switching loops; separate from analog ground |
| SW1 | Switching node (P1/N1) | Internal connection to PFET P1 and NFET N1; critical for buck-mode energy transfer |
| PVIN | Main power input | Supplies power switches; connect to 10-µF input capacitor near this pin |
| EN | Digital enable input | Active-high logic control; pull low to enter 0.01-µA shutdown state |
| VDD | Signal supply | Bias supply for control circuitry; recommended 1-µF decoupling capacitor |
| NC | No-connect terminal | Must be tied to SGND on PCB; no internal connection |
| SGND | Analog/control ground | Reference for FB, VSEL, MODE/SYNC; keep separate from PGND except at single-point DAP tie |
| MODE/SYNC | Mode selection or clock sync | Low = auto PFM-PWM; high = forced PWM; external 1.6–2.7 MHz clock accepted when high |
| VSEL | Output voltage select | Logic low → 3.0 V output; logic high → 3.4 V output; defines part variant identity |
| FB | Feedback input | Monitors output voltage via resistor divider; regulates VOUT to 0.6 V reference internally |
Key Features
| Feature | Design Value |
|---|---|
| Single-inductor buck-boost architecture | Eliminates need for separate buck + boost converters; reduces BOM count and board area by >40% vs dual-stage solutions |
| Automatic buck/boost mode transition | Seamless crossover at VIN ≈ VOUT without output glitch or regulation loss; no external control required |
| Integrated synchronous rectification | Uses internal N-channel MOSFETs as rectifiers instead of diodes; improves efficiency by 8–12% at 500-mA load |
| Internal soft-start | 600-µs max startup time after VIN settles; prevents inrush current and output overshoot during power-up |
| Hysteretic PFM mode | Reduces IQ to 45 µA at light loads; extends battery life in always-on peripherals like audio codecs or sensors |
Applications
| Handset Peripherals | MP3 Players |
|---|---|
Use Scenario: Powering camera modules, touch controllers, and audio codecs in smartphones where input voltage varies from 4.2 V (fresh battery) to 3.0 V (depleted). IC Role / Device Role / Timing Role: Primary pre-regulator converting Li-ion rail to stable 3.0 V or 3.4 V for low-noise analog subsystems. Use Value: Maintains regulation across full battery discharge while minimizing heat generation in thermally constrained handset frames. |
Use Scenario: Supplying DSP, flash memory, and OLED display drivers in portable music players with tight PCB space budgets. IC Role / Device Role / Timing Role: Single-chip DC-DC solution replacing discrete buck + LDO combinations for dual-voltage subsystems. Use Value: Achieves >90% efficiency at 300-mA load with 2.2-µH inductor, enabling 10+ hour playback on single-cell Li-ion. |
| Portable Hard Disk Drives | WiMax Modems |
Use Scenario: Providing clean 3.3-V rail for 2.5-inch HDD spindle motor drivers and SATA interface ICs during spin-up surges. IC Role / Device Role / Timing Role: High-current pre-regulator handling transient loads up to 1 A with fast line/load regulation response. Use Value: Delivers 1-A peak current at 3.3 V from 3.6-V nominal input, eliminating need for oversized input capacitors. |
Use Scenario: Powering RF front-end ICs and baseband processors in mobile broadband modems operating across wide temperature ranges. IC Role / Device Role / Timing Role: Efficient voltage translation from 3.7-V Li-ion to 3.4-V RF supply with thermal shutdown protection at 85°C ambient. Use Value: Sustains 800-mA output at 3.4 V even at 3.4-V input, enabling reliable operation during RF transmit bursts. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-mode buck-boost regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS63020DSJR | Fixed 3.3-V output only; no VSEL pin; 96% peak efficiency vs 94% for LM3668SDX-3034/NOPB | Requires external resistor network to adjust output; lacks programmable 3.0/3.4-V option | Select when fixed 3.3-V output suffices and higher efficiency at mid-load is prioritized |
| MAX8646ETE+ | Supports 2.5–5.5 V input but only 2.5–3.3 V output range; no 3.4-V option; 1.2-MHz switching | Cannot deliver 3.4-V output needed for certain RF bias rails; larger inductor required due to lower frequency | Select only if 3.4-V output is not required and board layout allows larger magnetics |
Compared with TPS63020DSJR and MAX8646ETE+, the LM3668SDX-3034/NOPB uniquely provides factory-trimmed 3.0 V/3.4 V dual-output selection via VSEL, enabling one BOM to support two voltage variants without redesign, while maintaining 2.2-MHz operation for minimal passive size.
Availability
LM3668SDX-3034/NOPB is available at Aetrix Electronics and suitable for handheld consumer electronics, portable storage devices, and wireless communication modules requiring stable component supply with guaranteed long-term manufacturability.
Supply support for LM3668SDX-3034/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 for portable and battery-powered systems.
The LM3668 product line was engineered specifically for space-constrained Li-ion applications demanding high efficiency across full battery voltage range, seamless buck-boost transition, and ultra-low quiescent current in standby - targeting handset, PDA, and portable media markets.
FAQ
What output voltages does the LM3668SDX-3034/NOPB support?
The LM3668SDX-3034/NOPB supports two factory-configured output voltages: 3.0 V when the VSEL pin is logic low (connected to GND), and 3.4 V when VSEL is logic high (connected to VIN). This dual-option capability is encoded in the part number suffix "3034" and requires no external resistors.
How does the LM3668SDX-3034/NOPB handle transitions between buck and boost modes?
The LM3668SDX-3034/NOPB performs automatic, seamless buck-to-boost and boost-to-buck transitions without output disturbance. Its internal error amplifier continuously monitors FB voltage and dynamically controls four internal MOSFETs to maintain regulation - no external circuitry or firmware intervention is needed for crossover operation.
What is the maximum load current the LM3668SDX-3034/NOPB can deliver at 3.4 V output?
At 3.4 V output, the LM3668SDX-3034/NOPB delivers up to 1 A when input voltage is 3.9–5.5 V, 800 mA at 3.4–3.8 V input, and 700 mA at 3.0–3.3 V input. These limits are defined by thermal constraints and internal current limiting (1.85 A typical peak switch current).
Can the LM3668SDX-3034/NOPB synchronize to an external clock?
Yes - when the MODE/SYNC pin is held high, the LM3668SDX-3034/NOPB enters forced PWM mode and accepts an external synchronization signal from 1.6 MHz to 2.7 MHz. This allows timing alignment with other system clocks to reduce EMI in noise-sensitive applications.
What package type and thermal characteristics apply to the LM3668SDX-3034/NOPB?
The LM3668SDX-3034/NOPB uses a 12-pin WSON (DQB) package (3.00 mm × 3.00 mm) with exposed die attach pad. Its junction-to-board thermal resistance (RθJB) is 21.6°C/W, and it features thermal shutdown at 150°C with automatic recovery below 125°C - critical for sustained operation in sealed portable enclosures.
LM3668SDX-3034/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 12-WFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Function:
- Step-Up/Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck-Boost
- Output Type:
- Programmable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2.5V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 3V, 3.4V
- Voltage - Output (Max):
- -
- Current - Output:
- 1A
- Frequency - Switching:
- 2.2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 12-WSON (3x3)
LM3668SDX-3034/NOPB FAQ
1.How can I place an order for LM3668SDX-3034/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3668SDX-3034/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 LM3668SDX-3034/NOPB reliable?
The price and inventory of LM3668SDX-3034/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3668SDX-3034/NOPB is usually 5 days.
3.What payment methods are accepted for LM3668SDX-3034/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3668SDX-3034/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3668SDX-3034/NOPB?
LM3668SDX-3034/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3668SDX-3034/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 LM3668SDX-3034/NOPB?
For technical support, including LM3668SDX-3034/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3668SDX-3034/NOPB requirements.
6.How does Aetrix verify that LM3668SDX-3034/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3668SDX-3034/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 LM3668SDX-3034/NOPB meets industry standards.
7.What is the process for return or replacement of LM3668SDX-3034/NOPB?
All LM3668SDX-3034/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3668SDX-3034/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 LM3668SDX-3034/NOPB part is unused and in its original packaging.
Return procedure for LM3668SDX-3034/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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