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Texas Instruments LM2678SD-5.0/NOPB
- Part No.:
- LM2678SD-5.0/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 14-VDFN Exposed Pad
- Datasheet:
-
LM2678SD-5.0/NOPB.pdf
- Description:
- IC REG BUCK 5V 5A 14VSON
- Quantity:
- Payment:
- Shipping:
Inventory:1,140
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Product details
Overview
LM2678SD-5.0/NOPB from Texas Instruments is a monolithic step-down (buck) DC-DC switching regulator delivering up to 5 A output current with fixed 5 V output, 8–40 V input range, 260 kHz fixed-frequency operation, and ±2% output voltage tolerance over full line/load/temperature. It integrates a 120 mΩ DMOS high-side switch and supports ON/OFF control for low-power standby mode.
For engineers reviewing the LM2678SD-5.0/NOPB datasheet, LM2678SD-5.0/NOPB pinout, LM2678SD-5.0/NOPB application, or LM2678SD-5.0/NOPB equivalent, key selection criteria include thermal performance in TO-263-7 (KTW), efficiency at 5 A load, feedback configuration for fixed-output use, and compatibility with standard off-the-shelf inductors and Schottky diodes.
Technical Context
The LM2678SD-5.0/NOPB implements a voltage-mode PWM controller with internal 260 kHz oscillator, driving an integrated high-side DMOS FET. Its fixed 5 V output eliminates external feedback resistors-pin 6 (FB) connects directly to VOUT-and regulation relies on internal precision reference and error amplifier.
Operation requires external components: bootstrap capacitor (CB) between pins 3 and 1, input/output capacitors, power inductor, and catch diode. Thermal shutdown, current limiting, and ON/OFF pin (pin 7) enable robust system-level control across –40°C to +125°C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 5.0 V, ±2% tolerance over full line, load, and temperature (–40°C to 125°C) |
| Max Output Current | 5 A continuous; limited by thermal design and PCB copper area in KTW package |
| Input Voltage Range | 8 V to 40 V DC-supports wide industrial and battery-derived supplies |
| Switching Frequency | 260 kHz fixed (±11% tolerance); enables compact magnetics and predictable EMI profile |
| RDS(ON) | 120 mΩ typical at TJ = 25°C; reduces conduction loss and improves full-load efficiency |
| Standby Current | 50 µA max when ON/OFF pin pulled low; enables ultra-low-power system sleep states |
| Efficiency | 84% typical at VIN = 12 V, IOUT = 5 A-achieved via low-RDS(ON) switch and optimized gate drive |
Pinout & Package
LM2678SD-5.0/NOPB uses the KTW (TO-263-7) thermally enhanced surface-mount package: 10.1 mm × 15.24 mm footprint with exposed thermal pad (DAP) soldered to PCB ground plane for optimal heat dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (SW) | Switch output | Drain node of internal high-side DMOS FET; connects to inductor and cathode of external Schottky diode-high dv/dt node requiring careful layout |
| 2 (IN) | Input supply | Main power input (8–40 V); must be bypassed with low-ESR capacitor placed adjacent to pin for stable high-frequency operation |
| 3 (CB) | Bootstrap capacitor | Connects to SW pin via 100 nF ceramic capacitor to generate gate drive voltage > VIN for full FET enhancement |
| 4 (GND) | Power ground | Primary return path for input/output capacitors and thermal pad; requires low-inductance connection to system ground plane |
| 5 (NC) | No connect | Internally unconnected; must remain floating-no routing or soldering permitted |
| 6 (FB) | Feedback input | Internally tied to 5 V reference for fixed-output version; connect directly to VOUT node for regulation-no external divider needed |
| 7 (ON/OFF) | Enable control | Logic-level input: ≥1.4 V = active regulation; ≤0.8 V = shutdown (50 µA IQ); internal 20 µA pull-up allows open-circuit enable |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 120 mΩ DMOS switch | Enables 5 A output without external MOSFET; reduces BOM count and layout complexity versus controller-only solutions |
| Fixed 5 V output configuration | Eliminates external feedback resistor network-simplifies design, improves accuracy, and removes resistor tolerance drift |
| 260 kHz fixed-frequency PWM | Allows consistent filter design and EMI filtering; avoids frequency jitter issues common in variable-frequency converters |
| Thermal shutdown & current limit | Protects device under overload or poor heatsinking; current limit threshold is 6.1–8.3 A depending on temperature |
| ON/OFF pin with 50 µA standby | Supports system-level power sequencing and low-power sleep modes without external logic or LDO control |
Applications
| Industrial Power Supply | Automotive Body Control Module |
|---|---|
Use Scenario: Distributed 5 V rail generation from 12–24 V battery or bus in programmable logic controllers and sensor hubs. IC Role / Device Role / Timing Role: Primary buck regulator supplying microcontroller core, CAN transceivers, and analog front-ends. Use Value: Delivers stable 5 V at up to 5 A with <±2% tolerance across wide input range and ambient temperatures, reducing need for post-regulation LDOs. | Use Scenario: Centralized 5 V supply for door modules, lighting drivers, and window lift ECUs in 12 V automotive systems. IC Role / Device Role / Timing Role: High-current step-down converter handling cold-crank (6.5 V) to load-dump (40 V) transients per ISO 7637-2. Use Value: Withstands 8–40 V input range and –40°C to +125°C operation; built-in current limit and thermal shutdown ensure reliability during fault conditions. |
| Point-of-Load Converter | Battery-Powered Test Equipment |
Use Scenario: Local 5 V conversion near FPGA or DSP on dense digital boards with tight space constraints. IC Role / Device Role / Timing Role: Compact, thermally efficient buck regulator minimizing voltage drop and noise coupling to sensitive logic. Use Value: TO-263-7 package with exposed DAP enables direct thermal transfer to inner PCB layers-critical for high-density layouts without heatsinks. | Use Scenario: Portable calibration tools and handheld analyzers requiring long runtime from Li-ion or lead-acid packs. IC Role / Device Role / Timing Role: Main system regulator enabling deep-sleep modes via ON/OFF pin control and ultra-low 50 µA standby current. Use Value: Standby current specification ensures minimal battery drain during idle periods-extending operational time between charges. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2596S-5.0 | 3 A max output, 150 kHz switching frequency, higher RDS(ON) (~200 mΩ), TO-263-5 package | Limited to lower current loads; less efficient at 5 A due to higher conduction loss and lower frequency requiring larger magnetics | Select when cost sensitivity outweighs current capability and efficiency requirements |
| TPS54560B | 5.5 A max, 100 V input, adjustable output, 2.2 MHz switching, SOIC-8 package | Requires external feedback resistors and compensation; supports wider input but lacks fixed 5 V option and integrated thermal pad | Select when input exceeds 40 V or high-frequency operation is required to shrink passive size |
Compared with LM2678SD-5.0/NOPB, LM2596S-5.0 offers lower cost but sacrifices 40% current headroom and thermal performance, while TPS54560B provides greater input flexibility and frequency agility at the expense of design simplicity and fixed-output convenience.
Availability
LM2678SD-5.0/NOPB is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, and portable test equipment requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LM2678SD-5.0/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 specializing in analog, embedded processing, and power management ICs, with leadership in high-reliability industrial and automotive solutions.
The LM2678 series belongs to TI's SIMPLE SWITCHER® power converter family-designed for ease of use in non-isolated DC-DC buck applications where fast time-to-market, minimal external components, and proven thermal robustness are critical.
FAQ
What is the maximum recommended output current for LM2678SD-5.0/NOPB in continuous operation?
The LM2678SD-5.0/NOPB is rated for up to 5 A continuous output current under proper thermal conditions. Achieving this requires adequate PCB copper area (≥0.4896 in² for KTW package), forced airflow or heatsinking if ambient exceeds 60°C, and adherence to recommended layout guidelines for GND and thermal pad connections. Derating applies above 85°C ambient.
Does LM2678SD-5.0/NOPB require external feedback resistors to set the 5 V output?
No. The LM2678SD-5.0/NOPB is a fixed-output variant: its internal feedback divider is factory-trimmed for 5.0 V, so pin 6 (FB) must be connected directly to the output capacitor node-no external resistors are needed. This eliminates resistor tolerance errors and simplifies layout versus adjustable versions like LM2678-ADJ.
What package type does LM2678SD-5.0/NOPB use, and how is thermal performance achieved?
The LM2678SD-5.0/NOPB uses the KTW (TO-263-7) package with an exposed thermal pad (DAP). Thermal performance relies on soldering the DAP to a large PCB copper pour connected to ground-TI specifies RθJA as low as 35°C/W with 0.4896 in² of 1 oz. copper. Proper thermal vias under the pad are essential to meet junction temperature limits at full load.
Can LM2678SD-5.0/NOPB operate from a 6 V input supply?
No. The LM2678SD-5.0/NOPB has a minimum input voltage of 8 V per its absolute operating conditions. Attempting to operate below 8 V will prevent startup or cause erratic regulation. For sub-8 V inputs, consider alternatives such as the TPS54302 (2.5–6.0 V input) or redesign with a pre-regulator stage before the LM2678SD-5.0/NOPB.
How does the ON/OFF pin function on LM2678SD-5.0/NOPB, and what voltage levels enable/disable it?
The ON/OFF pin (pin 7) controls regulator enable state: a voltage ≥1.4 V (typical) enables switching and regulation; ≤0.8 V (typical) forces shutdown with only 50 µA quiescent current. The pin features an internal 20 µA pull-up, so leaving it open defaults to ON. Do not exceed 6 V to avoid damage per absolute maximum ratings.
LM2678SD-5.0/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 14-VDFN Exposed Pad
- 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):
- 8V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 5V
- Voltage - Output (Max):
- -
- Current - Output:
- 5A
- Frequency - Switching:
- 260kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-VSON (5x6)
LM2678SD-5.0/NOPB FAQ
1.How can I place an order for LM2678SD-5.0/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2678SD-5.0/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 LM2678SD-5.0/NOPB reliable?
The price and inventory of LM2678SD-5.0/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2678SD-5.0/NOPB is usually 5 days.
3.What payment methods are accepted for LM2678SD-5.0/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2678SD-5.0/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2678SD-5.0/NOPB?
LM2678SD-5.0/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2678SD-5.0/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 LM2678SD-5.0/NOPB?
For technical support, including LM2678SD-5.0/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2678SD-5.0/NOPB requirements.
6.How does Aetrix verify that LM2678SD-5.0/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2678SD-5.0/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 LM2678SD-5.0/NOPB meets industry standards.
7.What is the process for return or replacement of LM2678SD-5.0/NOPB?
All LM2678SD-5.0/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2678SD-5.0/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 LM2678SD-5.0/NOPB part is unused and in its original packaging.
Return procedure for LM2678SD-5.0/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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