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Texas Instruments LM2678SDX-5.0
- Part No.:
- LM2678SDX-5.0
- Manufacturer:
- Texas Instruments
- Package:
- 14-VDFN Exposed Pad
- Datasheet:
-
LM2678SDX-5.0.pdf
- Description:
- IC REG BUCK 5V 5A 14VSON
- Quantity:
- Payment:
- Shipping:
Inventory:1,840
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Product details
Overview
LM2678SDX-5.0 from Texas Instruments is a monolithic 5A step-down (buck) DC/DC voltage regulator with fixed 5.0V output, 8V–40V input range, 260 kHz fixed-frequency PWM control, and integrated 120 mΩ DMOS power switch. It delivers high-efficiency regulation for industrial power supplies, battery chargers, and system pre-regulators requiring stable 5V at up to 5A.
For engineers reviewing the LM2678SDX-5.0 datasheet, LM2678SDX-5.0 pinout, LM2678SDX-5.0 application, or LM2678SDX-5.0 equivalent, key selection criteria include its ±2% output tolerance over line/load/temperature, 50 μA standby current in shutdown, thermal shutdown and current limiting protection, and compatibility with standard off-the-shelf inductors and Schottky diodes per TI's SIMPLE SWITCHER® design methodology.
Technical Context
The LM2678SDX-5.0 implements a voltage-mode PWM controller with internal 260 kHz oscillator, cycle-by-cycle current limiting, and thermal shutdown. Its feedback loop uses an internal resistive divider to set 5.0V output, eliminating external resistors while maintaining ±2% accuracy across −40°C to +125°C junction temperature.
It integrates a low-RDS(on) (120 mΩ typical) DMOS power switch and requires only five external components: input capacitor, output capacitor, catch diode, inductor, and boost capacitor. The ON/OFF pin enables logic-level enable control with 0.8V–2.0V threshold and 50 μA shutdown quiescent current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 5.0V ±2% over full line, load, and temperature (−40°C to +125°C) |
| Input Voltage Range | 8V to 40V - supports wide industrial and battery-derived inputs without pre-regulation |
| Max Output Current | 5A continuous - enables single-chip conversion for mid-power systems |
| Switching Frequency | 260 kHz fixed - enables use of compact, standardized inductors and predictable EMI filtering |
| Efficiency | 84% typical at 12VIN/5VOUT/5A - reduces thermal load vs. linear regulators |
| Quiescent Current | 50 μA in shutdown - preserves battery life in always-on or low-power standby modes |
| Thermal Protection | Integrated thermal shutdown - disables output above safe junction temperature (125°C+) |
Pinout & Package
VSON-14 (Package Number NHM0014A) with exposed die attach pad (DAP) for enhanced thermal performance. DAP must be connected to PCB ground plane per TI AN-1187.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VSW) | Switch Node | Drives external inductor; swings between VIN and ~−0.5V during switching; connects to boost capacitor |
| 2 (VIN) | Power Input | Primary supply input (8V–40V); powers internal circuitry and switch; requires local bypass capacitor |
| 3 (CBOOST) | Boost Capacitor Terminal | Connects 0.01 μF ceramic capacitor to VSW to generate gate drive >VIN for full MOSFET enhancement |
| 4–6, 10–11 (GND) | Ground Return | Low-impedance return path for power and signal; multiple pins reduce IR drop and improve stability |
| 7 (ON/OFF) | Enable Control | Logic-compatible shutdown input; <0.8V disables regulator; internal 20 μA pull-up; 50 μA IQ in OFF state |
| 8 (FB) | Feedback Input | Internally tied to 5.0V divider; no external resistors needed; monitors output for regulation |
| 9 (DAP) | Thermal Pad | Exposed copper pad; must be soldered to PCB ground plane for θJA = 29°C/W (12-via layout) |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 120 mΩ DMOS Switch | Eliminates external MOSFET; reduces BOM count and layout complexity while enabling 5A operation |
| ±2% Output Accuracy | Guaranteed over full temperature, line, and load - avoids post-production trimming or calibration |
| 260 kHz Fixed-Frequency Operation | Enables deterministic EMI filtering and simplifies inductor selection using TI-recommended parts |
| 50 μA Shutdown Current | Supports ultra-low-power system states without auxiliary LDOs or external switches |
| Built-in Thermal Shutdown & Current Limit | Self-protecting under overload or poor heatsinking - no external fault management circuitry required |
Applications
| Industrial Power Supply | Battery Charger Pre-Regulator |
|---|---|
|
Use Scenario: 24V rail conversion to clean 5V for PLC I/O modules and sensor interfaces. IC Role / Device Role / Timing Role: Primary buck regulator delivering regulated 5V at up to 5A with line/load regulation <±0.5%. Use Value: Replaces discrete buck controllers + MOSFETs; achieves 84% efficiency at full load, reducing heatsink size by >40% vs. linear solution. |
Use Scenario: Intermediate 5V rail generation from 12–36V battery packs for USB-powered peripherals and charge management ICs. IC Role / Device Role / Timing Role: High-current pre-regulator ensuring stable 5V supply independent of battery SOC or charging transients. Use Value: 8V–40V input range accommodates wide battery voltage swing; 50 μA shutdown extends standby time in portable systems. |
| Embedded System Pre-Regulator | Test Equipment Power Module |
|
Use Scenario: Generating 5V for FPGA core/logic rails in field-deployable instrumentation with variable input sources. IC Role / Device Role / Timing Role: Robust primary DC/DC stage with built-in current limit and thermal protection for unattended operation. Use Value: Integrated protection eliminates need for external current-sense amplifiers or thermal sensors; simplifies safety certification. |
Use Scenario: Benchtop power module supplying 5V/5A to DUTs with precise voltage stability and fast transient response. IC Role / Device Role / Timing Role: Regulated output stage with <100 mV load-step ripple (typ.) and 100 μs recovery per TI characterization data. Use Value: Fixed 5.0V output eliminates resistor tolerance errors; ±2% tolerance ensures compliance with USB 2.0 and TTL logic specs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2678T-5.0 | TO-220-7 package; higher θJA (65°C/W, no heatsink); same electrical specs | Requires external heatsink for >2A continuous; less suitable for space-constrained PCBs | Choose when mechanical mounting or through-hole assembly is preferred over surface-mount density |
| LM2596S-5.0 | 3A max output; 150 kHz switching; different pinout and external component requirements | Limited to lower current loads; requires redesign of inductor/capacitor values and layout | Acceptable only if 3A suffices and board rework is feasible; not pin- or footprint-compatible |
Compared with LM2678SDX-5.0, the TO-220 LM2678T-5.0 trades thermal performance for ease of prototyping, while the LM2596S-5.0 reduces cost and complexity at the expense of current capability and frequency flexibility - neither offers drop-in replacement capability.
Availability
LM2678SDX-5.0 is available at Aetrix Electronics and suitable for industrial power supplies, battery charger subsystems, and embedded system pre-regulators requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LM2678SDX-5.0 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, embedded processing, and power management technologies with over 50 years of innovation in high-reliability power conversion.
The LM2678 series belongs to TI's SIMPLE SWITCHER® portfolio - designed specifically to simplify high-efficiency DC/DC buck regulator implementation using minimal external components and industry-standard passives.
FAQ
What is the maximum recommended input voltage for LM2678SDX-5.0?
The absolute maximum input voltage rating for LM2678SDX-5.0 is 45V, but the recommended operating range is 8V to 40V per the datasheet. Exceeding 40V risks violating the specified operating conditions and may degrade long-term reliability or trigger overvoltage stress on internal circuitry. For designs with transient spikes, ensure clamping or filtering keeps sustained input within 40V.
Does LM2678SDX-5.0 require external feedback resistors?
No, LM2678SDX-5.0 does not require external feedback resistors. It is a fixed-output variant with internal resistor divider network configured for 5.0V output. Pin 8 (FB) is internally connected to this divider, so direct connection to the output rail is sufficient for regulation - no external components are needed for voltage setting.
What thermal performance can be expected from LM2678SDX-5.0 in a standard PCB layout?
In a standard VSON-14 layout with the DAP connected to a 1.0064 in² copper area and 12 thermal vias, LM2678SDX-5.0 achieves θJA = 29°C/W. At 5A output and 12V input, dissipation is ~3.5W; this yields ~102°C rise above ambient, keeping junction temperature within the −40°C to +125°C rating when ambient stays below 23°C - derating is required for higher ambient or reduced copper area.
Can LM2678SDX-5.0 be synchronized to an external clock?
No, LM2678SDX-5.0 cannot be synchronized to an external clock. It uses an internal fixed-frequency 260 kHz oscillator with ±11% tolerance. There is no external sync pin or frequency adjustment capability - synchronization requires alternative regulators such as the TPS543x or LM5116 families.
Is LM2678SDX-5.0 RoHS compliant and lead-free?
Yes, LM2678SDX-5.0 is RoHS compliant and lead-free per Texas Instruments' product change notifications. The VSON-14 package uses matte tin (Sn) lead finish and meets JEDEC J-STD-020 moisture sensitivity level 3 (MSL-3), requiring bake prior to reflow if exposed to ambient beyond floor life.
LM2678SDX-5.0 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 14-VDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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)
LM2678SDX-5.0 FAQ
1.How can I place an order for LM2678SDX-5.0 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2678SDX-5.0 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 LM2678SDX-5.0 reliable?
The price and inventory of LM2678SDX-5.0 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2678SDX-5.0 is usually 5 days.
3.What payment methods are accepted for LM2678SDX-5.0?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2678SDX-5.0 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2678SDX-5.0?
LM2678SDX-5.0 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2678SDX-5.0 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 LM2678SDX-5.0?
For technical support, including LM2678SDX-5.0 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2678SDX-5.0 requirements.
6.How does Aetrix verify that LM2678SDX-5.0 is sourced from the original manufacturer or authorized distributors?
All LM2678SDX-5.0 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 LM2678SDX-5.0 meets industry standards.
7.What is the process for return or replacement of LM2678SDX-5.0?
All LM2678SDX-5.0 units undergo pre-shipment inspection (PSI). If there is an issue with LM2678SDX-5.0, 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 LM2678SDX-5.0 part is unused and in its original packaging.
Return procedure for LM2678SDX-5.0:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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