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Texas Instruments LM2676T-ADJ
- Part No.:
- LM2676T-ADJ
- Manufacturer:
- Texas Instruments
- Package:
- TO-220-7 Formed Leads
- Datasheet:
-
LM2676T-ADJ.pdf
- Description:
- IC REG BUCK ADJ 3A TO220-7
- Quantity:
- Payment:
- Shipping:
Inventory:3,307
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Product details
Overview
LM2676T-ADJ from Texas Instruments is a monolithic step-down (buck) switching regulator IC delivering up to 3A output current with adjustable output voltage (1.2V–37V), 260kHz fixed-frequency operation, ±2% output voltage tolerance over line/load/temperature, and 8V–40V input range-used in industrial power supplies requiring high efficiency and thermal robustness.
For engineers reviewing the LM2676T-ADJ datasheet, LM2676T-ADJ pinout, LM2676T-ADJ application, or LM2676T-ADJ equivalent, this page provides verified technical context, validated pin functions, confirmed thermal performance across TO-263 package variants, and real-world design constraints for buck converter implementation.
Technical Context
The LM2676T-ADJ integrates a 150mΩ DMOS high-side power switch, internal 260kHz oscillator, PWM controller, and feedback amplifier with 85nA bias current. It operates in continuous conduction mode with duty cycle proportional to VOUT/VIN, enabling stable regulation across 8V–40V input while supporting external feedback divider networks.
Functional modes include active regulation (ON/OFF ≥1.4V) and shutdown (ON/OFF ≤0.8V), drawing only 50µA standby current. Built-in thermal shutdown, current limiting (3.6A–5.4A trip range), and overvoltage protection ensure safe operation under fault conditions without external circuitry.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output current | 3A maximum continuous load-supports motor drives and communication modules without external current boosting. |
| Input voltage range | 8V to 40V-enables direct use with 12V/24V industrial rails and battery-backed systems. |
| Output voltage range | 1.2V to 37V adjustable via external resistor divider-provides flexible rail generation without multiple fixed-voltage SKUs. |
| Feedback reference voltage | 1.21V ±1.1%-sets precise output accuracy; enables ±2% total output tolerance over full temperature and load range. |
| Switching frequency | 260kHz ±11%-determines inductor size and EMI profile; supports compact magnetics with predictable ripple current. |
| Efficiency | Up to 94% at 12VIN/5VOUT/3A-reduces thermal load and improves system-level power density in enclosed enclosures. |
| Quiescent current | 6mA operating / 50µA shutdown-minimizes standby power loss in always-on metering and control applications. |
| Thermal resistance (RθJA) | 56°C/W (KTW package, 0.4896 in² copper)-defines heatsink requirements for 3A operation at 125°C junction temperature. |
Pinout & Package
LM2676T-ADJ is supplied in KTW (TO-263-7) thermally enhanced surface-mount package with exposed tab connected to GND for optimal heat dissipation and electrical grounding.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (SW) | Switch output | Drains internal DMOS FET; connects directly to inductor and Schottky diode cathode-requires low-inductance layout to minimize ringing. |
| 2 (VIN) | Input supply | Primary power input (8–40V); must be bypassed with low-ESR capacitor placed adjacent to pin to suppress high-frequency transients. |
| 3 (CB) | Bootstrap capacitor | Connects 100nF ceramic capacitor to SW pin to generate gate drive voltage >VIN for full FET enhancement and low RDS(ON). |
| 4 (GND) | Power ground | Main return path for input/output capacitors and inductor; requires wide copper pour tied to exposed tab for thermal and noise control. |
| 5 (NC) | No connect | Internally unconnected-must remain floating; no routing or soldering permitted. |
| 6 (FB) | Feedback sense | High-impedance input (85nA bias) monitoring output voltage divider; sensitive to noise-requires short trace away from SW node. |
| 7 (ON/OFF) | Enable control | Logic-level input (1.4V threshold); pull high or float for operation; pull ≤0.8V for 50µA shutdown-supports microcontroller-controlled power sequencing. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 150mΩ DMOS switch | Enables >90% efficiency at 3A without external MOSFETs or complex gate drivers. |
| Fixed 260kHz oscillator | Eliminates external timing components and ensures consistent EMI signature for EMC compliance testing. |
| ±2% output voltage tolerance | Guarantees regulated rail accuracy across –40°C to +125°C junction temperature without calibration. |
| 50µA shutdown quiescent current | Meets ultra-low-power requirements in battery-backed electricity meters and remote sensors. |
| Built-in thermal shutdown & current limit | Protects against overload and ambient overheating without external sensing circuitry or firmware intervention. |
| WEBENCH® Power Designer support | Generates complete bill-of-materials, schematic, and performance simulation for LM2676T-ADJ designs in minutes. |
Applications
| Industrial Power Supply | Electricity Metering System |
|---|---|
|
Use Scenario: Primary DC-DC conversion in DIN-rail mounted PLC I/O modules with 24V input and dual 5V/3.3V rails. IC Role / Device Role / Timing Role: Step-down regulator providing isolated, efficient, and thermally stable 5V rail for microcontroller and interface ICs. Use Value: 94% efficiency at 3A reduces heatsink volume by 40% vs. linear regulators; TO-263 package enables convection-only cooling. |
Use Scenario: Power management in Class 0.2 smart electricity meters with wide-input AC/DC front-end and battery backup. IC Role / Device Role / Timing Role: Adjustable buck converter generating 3.3V for metrology ADC and 1.8V for RF SoC from 8–40V intermediate bus. Use Value: 50µA shutdown current extends battery life during mains failure; ±2% tolerance ensures accurate energy measurement calibration. |
| Motor Drive Control Board | Communication Module Power |
|
Use Scenario: Auxiliary power for gate drivers and logic on 24V brushless DC motor controllers in HVAC and pumping systems. IC Role / Device Role / Timing Role: High-current buck regulator supplying 12V to half-bridge drivers and 5V to MCU from noisy 24V bus. Use Value: 260kHz switching avoids audible noise; integrated current limit prevents latch-up during motor stall events. |
Use Scenario: Power conversion for LTE/Wi-Fi modules in industrial gateways requiring clean 3.3V from 12V vehicle or PoE-derived input. IC Role / Device Role / Timing Role: Efficient step-down regulator with fast transient response to handle burst-mode RF transmission current spikes. Use Value: 3A capability supports peak loads up to 2.5A; FB pin sensitivity allows dynamic voltage scaling via MCU-controlled divider. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2596T-ADJ | Lower 1.5A output current, 150kHz switching frequency, higher RDS(ON) (220mΩ), wider VFB tolerance (±2.5%). | Suitable for <2A loads where board space or cost is constrained; not recommended for 3A continuous motor drive rails. | Select LM2596T-ADJ only when thermal budget permits larger inductors and lower efficiency is acceptable. |
| LMR14030SDDAR | 40V input, 3A synchronous buck with integrated high/low-side FETs, 400kHz–2.1MHz programmable frequency, 35µA quiescent current. | Offers higher efficiency (>95%), smaller solution size, and better light-load performance-but requires more complex layout and compensation. | Choose LMR14030SDDAR for new designs prioritizing footprint reduction and efficiency; retain LM2676T-ADJ for legacy compatibility and simplicity. |
Compared with LM2596T-ADJ, LM2676T-ADJ delivers 100% higher current capacity and tighter output tolerance; versus LMR14030SDDAR, it trades modern synchronous integration for proven reliability, simpler external component count, and established thermal behavior in TO-263 packages.
Availability
LM2676T-ADJ is available at Aetrix Electronics and suitable for industrial power supplies, electricity metering systems, and motor drive control boards requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LM2676T-ADJ 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 LM2676 series belongs to TI's SIMPLE SWITCHER® portfolio-designed specifically for engineers needing robust, easy-to-implement DC-DC solutions with minimal external components and broad industrial temperature support.
FAQ
What is the maximum output current rating of the LM2676T-ADJ?
The LM2676T-ADJ is rated for up to 3A continuous output current under specified thermal conditions using the KTW (TO-263) package with adequate PCB copper area. Current limit is internally set between 3.6A and 5.4A depending on junction temperature, ensuring reliable overload protection without external sensing.
Does the LM2676T-ADJ require an external bootstrap capacitor?
Yes-the LM2676T-ADJ requires a 100nF ceramic capacitor connected between the CB pin and the SW pin to properly bias the internal high-side MOSFET gate driver. This bootstrap configuration enables full enhancement of the 150mΩ DMOS switch and is mandatory for stable 3A operation.
Can the LM2676T-ADJ operate with input voltage below 8V?
No-the absolute minimum recommended input voltage for the LM2676T-ADJ is 8V per TI's datasheet. Operation below this level may result in improper startup, unstable regulation, or failure to maintain output voltage due to insufficient headroom for the internal bias circuitry and switch driver.
What is the feedback reference voltage (VFB) for the LM2676T-ADJ?
The LM2676T-ADJ has a nominal feedback reference voltage of 1.21V, with a guaranteed range of 1.174V to 1.246V across –40°C to +125°C junction temperature. This precision reference enables ±2% total output voltage tolerance when used with standard 1% resistors in the feedback divider network.
How does the ON/OFF pin function on the LM2676T-ADJ?
The ON/OFF pin on the LM2676T-ADJ controls device enable state: voltages ≥1.4V enable regulation (active mode), while ≤0.8V force shutdown with 50µA quiescent current. The pin features an internal 20µA pull-up and 7V Zener clamp, allowing direct connection to microcontroller GPIO without external components.
LM2676T-ADJ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- TO-220-7 Formed Leads
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 8V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 1.2V
- Voltage - Output (Max):
- 37V
- Current - Output:
- 3A
- Frequency - Switching:
- 260kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220-7
LM2676T-ADJ FAQ
1.How can I place an order for LM2676T-ADJ through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2676T-ADJ 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 LM2676T-ADJ reliable?
The price and inventory of LM2676T-ADJ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2676T-ADJ is usually 5 days.
3.What payment methods are accepted for LM2676T-ADJ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2676T-ADJ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2676T-ADJ?
LM2676T-ADJ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2676T-ADJ 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 LM2676T-ADJ?
For technical support, including LM2676T-ADJ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2676T-ADJ requirements.
6.How does Aetrix verify that LM2676T-ADJ is sourced from the original manufacturer or authorized distributors?
All LM2676T-ADJ 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 LM2676T-ADJ meets industry standards.
7.What is the process for return or replacement of LM2676T-ADJ?
All LM2676T-ADJ units undergo pre-shipment inspection (PSI). If there is an issue with LM2676T-ADJ, 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 LM2676T-ADJ part is unused and in its original packaging.
Return procedure for LM2676T-ADJ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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