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Texas Instruments LM2678SD-5.0
- Part No.:
- LM2678SD-5.0
- Manufacturer:
- Texas Instruments
- Package:
- 14-VDFN Exposed Pad
- Datasheet:
-
LM2678SD-5.0.pdf
- Description:
- IC REG BUCK 5V 5A 14VSON
- Quantity:
- Payment:
- Shipping:
Inventory:2,466
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Product details
Overview
LM2678SD-5.0 from Texas Instruments is a monolithic 5A step-down (buck) DC/DC voltage regulator with fixed 5.0V output, 260 kHz fixed-frequency PWM control, 120 mΩ DMOS power switch, and operation across 8V–40V input range. It delivers high-efficiency regulation for industrial power supplies, battery chargers, and pre-regulators driving linear regulators.
For engineers reviewing the LM2678SD-5.0 datasheet, LM2678SD-5.0 pinout, LM2678SD-5.0 application, or LM2678SD-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 VSON-14 package with exposed thermal pad for high-power-density PCB layouts.
Technical Context
The LM2678SD-5.0 integrates a 120 mΩ DMOS power switch, fixed 260 kHz oscillator, and internal PWM controller with cycle-by-cycle current limiting. Its feedback loop uses a precision 1.21V reference and high-gain amplifier referenced to the FB pin, enabling stable regulation without external compensation components in standard configurations.
It operates in continuous conduction mode up to 5A load, supports ON/OFF control via a logic-level input with 0.8V–2.0V threshold, and features built-in thermal shutdown and frequency foldback under extreme overload-ensuring robustness in unattended or thermally constrained environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 5.0V ±2% over −40°C to +125°C junction temperature, 8V–40V input, 100mA–5A load - ensures compatibility with 5V logic and analog subsystems without external resistive divider. |
| Max Output Current | 5A continuous - supports high-current digital loads (e.g., FPGAs, microcontrollers with peripherals) without external current boosting. |
| Switching Frequency | 260 kHz ±11% - enables use of compact off-the-shelf inductors (e.g., 10–22 µH) while maintaining EMI below critical bands for industrial compliance. |
| Efficiency | 84% typical at VIN = 12V, IOUT = 5A - reduces thermal load and improves system energy efficiency versus lower-frequency or linear alternatives. |
| Quiescent Current | 4.2 mA typical operating, 50 μA standby when ON/OFF = 0V - enables low-power sleep modes in battery-backed or always-on systems. |
| Input Voltage Range | 8V to 40V - accommodates wide-input industrial rails (e.g., 12V/24V nominal with transients), automotive battery systems (with pre-regulation), and telecom intermediate buses. |
| Thermal Resistance | θJA = 29°C/W with 12 vias to inner copper layer - confirms effective heat dissipation in high-density VSON-14 layouts without external heatsink. |
Pinout & Package
The LM2678SD-5.0 is housed in a 14-pin VSON package (NHM0014A) with an exposed die attach pad (DAP) that must be soldered to a PCB ground plane for thermal and electrical performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pin 1) | Power Input | Accepts 8V–40V unregulated supply; requires local 0.1 µF ceramic + bulk capacitor for transient suppression and EMI control. |
| VSW (Pin 2) | Switch Node | Drives external catch diode and inductor; swings between VIN and ~−0.5V during switching - requires tight layout to minimize ringing and EMI. |
| CBOOST (Pin 3) | Bootstrap Capacitor Terminal | Connects to VSW via 0.01 µF/50V ceramic capacitor to generate gate drive >VIN for full enhancement of internal DMOS switch. |
| GND (Pin 4) | Power Ground | Main return path for high-current switch and control circuitry; must be tied directly to DAP and low-impedance ground plane. |
| ON/OFF (Pin 5) | Enable Control Input | Logic-compatible shutdown: <0.8V disables regulator (50 μA IQ); >2.0V enables; internal 20 μA pull-up allows open-circuit default ON. |
| FB (Pin 6) | Feedback Input | Internally connected to 5V output divider; no external resistors required - simplifies layout and eliminates trimming errors. |
| DAP (Exposed Pad) | Thermal & Electrical Ground | Mandatory PCB connection to solid ground copper area with ≥12 thermal vias - primary path for heat removal and noise reduction. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 120 mΩ DMOS Switch | Enables 5A output without external MOSFETs or gate drivers - reduces BOM count and layout complexity in space-constrained designs. |
| ±2% Output Tolerance | Guaranteed over full temperature, line, and load range - eliminates need for post-production calibration in industrial and medical applications. |
| 260 kHz Fixed-Frequency Operation | Provides predictable EMI profile and simplifies filter design versus variable-frequency controllers - compatible with TI's recommended inductor families. |
| Built-in Thermal Shutdown | Protects against sustained overloads or poor heatsinking by latching off above 160°C junction temperature - prevents catastrophic failure in sealed enclosures. |
| ON/OFF Pin with 50 μA Standby | Supports system-level power sequencing and ultra-low-power sleep states - critical for battery-powered test equipment and portable instrumentation. |
Applications
| Industrial Power Supply | Battery Charger Pre-Regulator |
|---|---|
Use Scenario: 24V industrial bus powering PLC I/O modules requiring clean, regulated 5V at up to 4A. IC Role / Device Role / Timing Role: Primary step-down regulator converting unregulated 24V rail to stable 5V supply with minimal external components. Use Value: Delivers 84% efficiency at full load, reducing heat sink size and enabling convection-only cooling in DIN-rail mounted enclosures. | Use Scenario: 36V lithium-ion battery pack charging system where 5V auxiliary rail powers charge management MCU and sensors. IC Role / Device Role / Timing Role: High-input-voltage pre-regulator stepping down battery voltage to fixed 5V before LDO post-regulation. Use Value: Wide 8V–40V input range accommodates full battery discharge curve (30V–42V), eliminating need for input voltage clamping or multiple regulators. |
| Embedded System Pre-Regulator | Test & Measurement Equipment |
Use Scenario: FPGA-based data acquisition system with mixed 5V/3.3V/1.8V rails, where 5V powers DDR memory interfaces and USB PHYs. IC Role / Device Role / Timing Role: High-current 5V source feeding downstream LDOs and point-of-load converters. Use Value: 5A capability and low output ripple (<50 mVpp) ensure stable memory operation and low jitter on high-speed serial links. | Use Scenario: Portable oscilloscope requiring low-noise, fast-transient 5V supply for analog front-end amplifiers and ADC reference circuits. IC Role / Device Role / Timing Role: Main 5V power stage with ON/OFF control synchronized to device power-on sequence. Use Value: 50 μA standby current extends battery life during idle periods; load transient response <100 µs maintains signal integrity during burst-mode sampling. |
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 | 3A max output, 150 kHz switching, TO-263-5 package - lower current, lower frequency, higher θJA (65°C/W). | Suitable for <3A loads with relaxed size/efficiency requirements; less demanding thermal layout. | Select when cost sensitivity outweighs current headroom and board space is not constrained. |
| TPS54560DGQR | 5A, 60V input, 2.5V–60V adjustable output, 100–2500 kHz programmable frequency, MSOP-10 - wider VIN, no fixed 5V variant, requires external feedback resistors. | Preferred for designs needing input >40V or flexible output voltage; adds design complexity but improves EMI tuning. | Choose when future-proofing for multi-voltage platforms or operating beyond 40V input limits. |
Compared with LM2596S-5.0, the LM2678SD-5.0 provides +2A output headroom and 110 kHz higher switching frequency for smaller magnetics; versus TPS54560DGQR, it offers plug-and-play 5V regulation without resistor selection or frequency configuration - accelerating time-to-prototype for fixed-output systems.
Availability
LM2678SD-5.0 is available at Aetrix Electronics and suitable for industrial power supplies, battery charger pre-regulators, and embedded system main 5V rails requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LM2678SD-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 ICs, with decades of expertise in high-reliability power conversion solutions.
The LM2678 series belongs to TI's SIMPLE SWITCHER® family - designed specifically for engineers seeking fast, reliable, and minimal-component buck regulator implementations in industrial, automotive, and communications infrastructure.
FAQ
What is the maximum input voltage rating for the LM2678SD-5.0?
The absolute maximum input voltage for the LM2678SD-5.0 is 45V, but the recommended operating range is 8V to 40V per the datasheet. Exceeding 40V continuously risks violating the guaranteed performance specifications and may accelerate parametric drift over temperature and lifetime. The LM2678SD-5.0 includes internal protection against short-term transients, but sustained operation above 40V is not characterized or warranted.
Does the LM2678SD-5.0 require external feedback resistors to set the output voltage?
No, the LM2678SD-5.0 does not require external feedback resistors. It is a fixed-output variant with internal resistor divider network calibrated to deliver 5.0V ±2% across temperature, line, and load. The FB pin is internally connected to this network, so a direct connection from FB to the output is sufficient - eliminating resistor tolerance errors and layout sensitivity inherent in adjustable versions.
How is thermal performance managed in the VSON-14 package of the LM2678SD-5.0?
The LM2678SD-5.0's VSON-14 package relies on the exposed die attach pad (DAP) soldered to a PCB ground plane with ≥12 thermal vias to achieve θJA = 29°C/W. This configuration provides significantly better thermal resistance than TO-220 or DDPAK variants. Without proper DAP grounding and via implementation, junction temperature can exceed safe limits at full 5A load - making thermal pad layout non-optional in production designs.
Can the LM2678SD-5.0 be used in discontinuous conduction mode (DCM)?
Yes, the LM2678SD-5.0 operates naturally in both continuous and discontinuous conduction modes depending on load current, inductance, and input voltage. At light loads (<500 mA), it transitions into DCM, reducing switching losses and improving light-load efficiency. The datasheet includes DCM waveforms and transient response plots confirming stable operation down to 200 mA, with no external mode-control circuitry required.
What protection features are integrated into the LM2678SD-5.0?
The LM2678SD-5.0 integrates cycle-by-cycle current limiting, thermal shutdown (latching above ~160°C), and frequency foldback during hard short-circuit conditions. It also features an ON/OFF pin with 50 μA standby quiescent current and internal clamp diodes on all pins rated for 2 kV HBM ESD. These protections operate autonomously without external components - ensuring robust field operation in harsh industrial environments.
LM2678SD-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)
LM2678SD-5.0 FAQ
1.How can I place an order for LM2678SD-5.0 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2678SD-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 LM2678SD-5.0 reliable?
The price and inventory of LM2678SD-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 LM2678SD-5.0 is usually 5 days.
3.What payment methods are accepted for LM2678SD-5.0?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2678SD-5.0 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2678SD-5.0?
LM2678SD-5.0 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2678SD-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 LM2678SD-5.0?
For technical support, including LM2678SD-5.0 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2678SD-5.0 requirements.
6.How does Aetrix verify that LM2678SD-5.0 is sourced from the original manufacturer or authorized distributors?
All LM2678SD-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 LM2678SD-5.0 meets industry standards.
7.What is the process for return or replacement of LM2678SD-5.0?
All LM2678SD-5.0 units undergo pre-shipment inspection (PSI). If there is an issue with LM2678SD-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 LM2678SD-5.0 part is unused and in its original packaging.
Return procedure for LM2678SD-5.0:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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