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Texas Instruments LM2677SD-12
- Part No.:
- LM2677SD-12
- Manufacturer:
- Texas Instruments
- Package:
- 14-VDFN Exposed Pad
- Datasheet:
-
LM2677SD-12.pdf
- Description:
- IC REG BUCK 12V 5A 14VSON
- Quantity:
- Payment:
- Shipping:
Inventory:3,419
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Product details
Overview
LM2677SD-12 from Texas Instruments is a monolithic step-down (buck) DC/DC voltage regulator with fixed 12 V output, integrated 100-mΩ DMOS power switch, 5-A load capability, 260-kHz internal oscillator, and ±2% output voltage tolerance over line/load/temperature. It delivers up to 92% efficiency at 24 VIN/5 A and supports external synchronization from 280 kHz to 400 kHz for EMI-sensitive communications and radio equipment.
For engineers reviewing the LM2677SD-12 datasheet, LM2677SD-12 pinout, LM2677SD-12 application, or LM2677SD-12 equivalent, key selection considerations include input voltage range (8–40 V), thermal performance in TO-263 package, ON/OFF control with 50-μA standby current, feedback architecture for fixed-output regulation, and compatibility with standard off-the-shelf inductors and low-ESR output capacitors.
Technical Context
The LM2677SD-12 implements a current-mode PWM buck controller with internal 260-kHz oscillator and externally synchronizable clock input (pin 5). Its DMOS high-side switch operates with RDS(ON) = 0.14 Ω (typ) at 25°C, enabling high-efficiency conversion across its full 8–40 V input range and 100 mA–5 A load range.
Regulation is achieved via a two-stage feedback amplifier sensing output voltage directly at the FB pin (pin 6); for the SD-12 variant, internal resistive divider sets VOUT = 12 V without external components. The ON/OFF pin (pin 7) enables shutdown with 50-μA quiescent current, while the CB pin (pin 3) supplies bootstrapped gate drive to the high-side FET through a 0.01-μF capacitor.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 12 V ±2% over –40°C to 125°C junction temperature, 15–40 V input, 100 mA–5 A load - ensures stable rail for downstream logic and analog circuitry without trimming. |
| Input Voltage Range | 8 V to 40 V - supports wide industrial, automotive, and telecom input sources including unregulated 24-V and 36-V bus systems. |
| Max Output Current | 5 A continuous - enables single-regulator solutions for high-power digital subsystems, FPGA core rails, or motor driver logic supplies. |
| Switch RDS(ON) | 0.14 Ω (typ) at 25°C - minimizes conduction loss and thermal rise under full load, supporting >92% peak efficiency at 24 VIN/5 A. |
| Oscillator Frequency | 260 kHz (internal, fixed) or 280–400 kHz (external sync) - allows consistent ripple frequency positioning for EMI filtering and avoids sensitive bands in RF receivers. |
| Standby Quiescent Current | 50 μA (typ) when ON/OFF pin < 0.8 V - enables ultra-low-power system sleep modes without auxiliary LDOs. |
| Thermal Shutdown | Integrated protection with automatic recovery - prevents damage during overload or poor heatsinking in enclosed industrial enclosures. |
Pinout & Package
LM2677SD-12 is packaged in a 7-pin TO-263 (KTW) surface-mount package with exposed thermal pad (DAP) for enhanced heat dissipation. Package dimensions are 10.16 mm × 8.69 mm, and the DAP must be soldered to a PCB ground plane per AN-1187 guidelines.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VSW (Pin 1) | High-side switch source node | Switching node connecting to inductor and external Schottky diode cathode; swings from VIN to ~–0.6 V; requires short, low-inductance layout. |
| VIN (Pin 2) | Power input supply | Connects to input bulk capacitor and high-frequency bypass cap; path to GND must be shortest possible to minimize switching noise coupling. |
| CB (Pin 3) | Bootstrap capacitor connection | Accepts 0.01-μF ceramic capacitor to VSW; provides gate drive voltage >VIN for full enhancement of internal DMOS switch. |
| GND (Pin 4) | Power ground reference | Primary return path for input/output capacitors and IC substrate; must connect to broad ground plane to limit EMI and improve transient response. |
| SYNC (Pin 5) | External clock input | Accepts TTL/CMOS clock (280–400 kHz); overrides internal 260-kHz oscillator; ac-coupled via 100-pF cap + 1-kΩ resistor to GND. |
| FB (Pin 6) | Feedback sense input | Internally connected to 12-V divider output; for LM2677SD-12, tied directly to output capacitor - no external resistors required. |
| ON/OFF (Pin 7) | Enable/disable control | Logic-level input: >1.4 V = active regulation; <0.8 V = shutdown (50-μA IQ); internal 20-μA pullup allows floating for always-on operation. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 100-mΩ DMOS switch | Enables self-contained 5-A buck conversion without external MOSFETs or drivers - reduces BOM count and layout complexity. |
| ±2% output voltage tolerance | Guaranteed over full temperature, line, and load range - eliminates need for post-production calibration in precision 12-V applications. |
| External sync capability (280–400 kHz) | Allows precise ripple frequency control for compliance with EMI standards and coexistence with sensitive RF receivers. |
| 50-μA standby current | Supports low-power system states without auxiliary regulators - critical for battery-backed or energy-harvesting industrial nodes. |
| Thermal shutdown + current limit | Provides fault protection without external circuitry - maintains reliability in overtemperature or short-circuit conditions. |
Applications
| Industrial PLC Power Supply | Telecom Line Card Bias Rail |
|---|---|
Use Scenario: Provides isolated 12-V bias for analog front-end circuitry and relay drivers in DIN-rail mounted programmable logic controllers. IC Role / Device Role / Timing Role: Primary step-down regulator converting 24-V DC field bus to stable 12-V rail; operates at fixed 260-kHz switching frequency. Use Value: Delivers 5-A continuous current with <1% output ripple (with recommended 400-μF/13-mΩ output capacitor), ensuring clean analog signal integrity and reliable solenoid actuation. |
Use Scenario: Generates 12-V supply for op-amps, ADCs, and interface ICs on carrier-grade line cards operating from -48-V DC telecom plant power. IC Role / Device Role / Timing Role: Preregulator stepping -48-V (via intermediate +24-V) down to 12-V; uses SYNC input to lock switching frequency to system master clock. Use Value: External synchronization eliminates beat frequencies with data clocks, reducing spurious tones in voice-band signals by >20 dB. |
| Automotive Infotainment Core Supply | Test Equipment Auxiliary Rail |
Use Scenario: Powers microcontroller cores and display timing controllers in head-unit designs where input voltage varies from 8 V (cold crank) to 16 V (load dump). IC Role / Device Role / Timing Role: Main 12-V buck converter with ON/OFF pin controlled by vehicle ignition signal; thermal shutdown protects against under-dash ambient temperatures. Use Value: Wide 8–40 V input range accommodates automotive transients without external pre-regulation; 92% peak efficiency minimizes heatsink requirements. |
Use Scenario: Supplies 12-V rail for calibration DACs, reference buffers, and sensor excitation circuits in benchtop multimeters and signal analyzers. IC Role / Device Role / Timing Role: Low-noise, tightly regulated secondary supply; FB pin decoupled with RC filter to suppress high-frequency switching artifacts. Use Value: ±2% output tolerance and <50-μVRMS output noise (with proper layout) ensure <0.01% measurement accuracy in precision metrology paths. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2678-12 | Same pinout and function but rated for 3-A output; lower RDS(ON) (0.11 Ω) and higher efficiency at light loads. | Suitable for cost-sensitive 12-V/3-A designs where full 5-A capability is unnecessary; smaller thermal footprint. | Select LM2678-12 only if load current remains ≤3 A and board space/thermal margin is constrained. |
| TPS54560DGQR | 60-V input, 5-A synchronous buck with integrated high/low-side FETs; adjustable output; 100-kHz–2.5-MHz frequency range. | Supports wider input range and higher switching frequencies for compact magnetics; lacks fixed 12-V option - requires external resistor divider. | Choose TPS54560DGQR when input exceeds 40 V or when PCB area savings from synchronous rectification outweigh added design complexity. |
Compared with LM2677SD-12, LM2678-12 offers reduced thermal stress at ≤3-A loads but cannot sustain 5-A continuously, while TPS54560DGQR extends input voltage range and enables higher-frequency operation but requires external feedback components and careful loop compensation - making LM2677SD-12 optimal for robust, drop-in 12-V/5-A industrial applications.
Availability
LM2677SD-12 is available at Aetrix Electronics and suitable for industrial automation, telecom infrastructure, and automotive infotainment systems requiring stable component supply, long-term lifecycle support, and traceable sourcing from authorized channels.
Supply support for LM2677SD-12 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 decades of expertise in high-reliability power conversion ICs.
The LM2677 series belongs to TI's SIMPLE SWITCHER® family - designed specifically for ease of use in cost-sensitive, high-efficiency DC/DC buck applications where minimal external components and proven layout guidance reduce time-to-market.
FAQ
What is the maximum input voltage rating for LM2677SD-12?
The absolute maximum input voltage for LM2677SD-12 is 45 V, but the recommended operating range is 8 V to 40 V per the datasheet. Operation above 40 V risks exceeding safe operating area limits and may trigger overvoltage protection or cause permanent damage. For automotive cold-crank scenarios down to 6 V, the device remains functional but requires verification of minimum duty cycle and startup behavior - LM2677SD-12 itself does not operate below 8 V.
Does LM2677SD-12 require external feedback resistors to set the 12-V output?
No, LM2677SD-12 does not require external feedback resistors. It is a fixed-output variant with internal resistor divider network configured for 12 V; the FB pin (pin 6) must be connected directly to the output capacitor's positive terminal. Adding external resistors would disrupt regulation and is not supported - only the adjustable version (LM2677T-ADJ) uses external R1/R2.
Can LM2677SD-12 synchronize to an external clock, and what are the interface requirements?
Yes, LM2677SD-12 supports external synchronization via the SYNC pin (pin 5) over 280 kHz to 400 kHz. The external clock must be TTL- or CMOS-compatible (0 V to >3 V), ac-coupled using a 100-pF capacitor and terminated with a 1-kΩ resistor to GND. Synchronization disables current-limit foldback, so short-circuit protection remains active but with fixed current threshold.
What thermal performance can be expected from LM2677SD-12 in the TO-263 package?
In the TO-263 (KTW) package with recommended 1.0064 in² copper area (7.4× package size), LM2677SD-12 achieves RθJA = 26°C/W. At 5-A load and 24-V input, typical power dissipation is ~1.8 W, resulting in ~47°C junction-to-ambient rise - well within the –40°C to 125°C operating range. Thermal shutdown activates at ~160°C junction temperature with automatic recovery.
Is LM2677SD-12 RoHS-compliant and halogen-free?
Yes, LM2677SD-12 is RoHS-compliant and halogen-free per Texas Instruments' official product change notices and packaging data. The TO-263 package uses lead-free matte tin plating, and all materials meet JEDEC J-STD-609A Class 1 requirements. Full compliance documentation is available in TI's Quality & Environmental section under SNVS077J revision history.
LM2677SD-12 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):
- 12V
- 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)
LM2677SD-12 FAQ
1.How can I place an order for LM2677SD-12 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2677SD-12 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 LM2677SD-12 reliable?
The price and inventory of LM2677SD-12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2677SD-12 is usually 5 days.
3.What payment methods are accepted for LM2677SD-12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2677SD-12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2677SD-12?
LM2677SD-12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2677SD-12 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 LM2677SD-12?
For technical support, including LM2677SD-12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2677SD-12 requirements.
6.How does Aetrix verify that LM2677SD-12 is sourced from the original manufacturer or authorized distributors?
All LM2677SD-12 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 LM2677SD-12 meets industry standards.
7.What is the process for return or replacement of LM2677SD-12?
All LM2677SD-12 units undergo pre-shipment inspection (PSI). If there is an issue with LM2677SD-12, 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 LM2677SD-12 part is unused and in its original packaging.
Return procedure for LM2677SD-12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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