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Texas Instruments LM2677S-5.0
- Part No.:
- LM2677S-5.0
- Manufacturer:
- Texas Instruments
- Package:
- TO-263-8, D2PAK (7 Leads + Tab), TO-263CA
- Datasheet:
-
LM2677S-5.0.pdf
- Description:
- IC REG BUCK 5V 5A TO263
- Quantity:
- Payment:
- Shipping:
Inventory:4,110
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Product details
Overview
LM2677S-5.0 from Texas Instruments is a monolithic step-down (buck) DC-DC voltage regulator delivering up to 5 A at a fixed 5 V output, featuring an integrated 100-mΩ DMOS power switch, 260-kHz internal oscillator, and ±2% output voltage tolerance over full line/load/temperature range. It operates from 8 V to 40 V input and supports external clock synchronization from 280 kHz to 400 kHz for EMI-sensitive communications equipment.
For engineers reviewing the LM2677S-5.0 datasheet, LM2677S-5.0 pinout, LM2677S-5.0 application, or LM2677S-5.0 equivalent, key selection criteria include input voltage range, output current capability, thermal performance in TO-263 package, standby current under ON/OFF control, and compatibility with standard off-the-shelf inductors and low-ESR output capacitors.
Technical Context
The LM2677S-5.0 implements a fixed-frequency PWM buck controller with internal 260-kHz oscillator and optional external sync input (pin 5), enabling precise ripple frequency positioning. Its high-side DMOS switch drives an external inductor-diode-capacitor network, with feedback sensed directly at the output for fixed 5-V regulation.
Operation includes active mode (ON/OFF ≥1.4 V), shutdown mode (ON/OFF ≤0.8 V, 50 μA standby), thermal shutdown, cycle-by-cycle current limiting (6.1–8.75 A), and bootstrap gate drive via CB pin requiring a 0.01-μF capacitor to VSW. The device uses internal gain-setting resistors-no external divider needed for 5-V output.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 5.0 V ±2% over –40°C to 125°C junction temperature, 8–40 V input, 100 mA–5 A load. |
| Max Output Current | 5 A continuous; current limit threshold 6.1–8.75 A depending on temperature. |
| Input Voltage Range | 8 V to 40 V DC; absolute maximum 45 V. |
| Switch RDS(ON) | 0.12–0.225 Ω (25°C to 125°C); enables >90% efficiency at full load with low conduction loss. |
| Oscillator Frequency | 260 kHz nominal (225–280 kHz over temperature); externally synchronizable to 280–400 kHz via SYNC pin. |
| Standby Quiescent Current | 50–150 μA when ON/OFF pin ≤0.8 V; enables ultra-low-power system sleep modes. |
| Thermal Resistance (θJA) | 26°C/W with 7.4× package copper area (TO-263); supports 5-A operation without heatsink in moderate ambient. |
Pinout & Package
LM2677S-5.0 is packaged in TO-263 (KTW) - a 7-pin surface-mount package with exposed thermal pad (DAP), 10.16 mm × 8.69 mm body size, and integrated heat dissipation path to PCB ground plane.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VSW (Pin 1) | Switch node output | Drives external inductor; swings between VIN and ~–0.5 V (Schottky drop); requires low-inductance layout to minimize EMI. |
| VIN (Pins 2,3) | Power input | Connects to 8–40 V supply and high-frequency input capacitor (CIN); dual pins reduce trace resistance and improve current sharing. |
| CB (Pin 3) | Bootstrap capacitor connection | Requires 0.01-μF ceramic capacitor to VSW to bias high-side gate driver above VIN for full MOSFET enhancement. |
| GND (Pin 4) | Power ground | Main return path for input/output currents; must connect directly to low-impedance PCB ground plane near CIN/COUT. |
| SYNC (Pin 5) | External clock input | Accepts TTL/CMOS clock (280–400 kHz); overrides internal oscillator; disables current-limit foldback when active. |
| FB (Pin 6) | Feedback sense | Internally connected to 5-V output divider; short directly to output capacitor for fixed 5-V operation-no external resistors required. |
| ON/OFF (Pin 7) | Enable 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 use. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 100-mΩ DMOS switch | Enables 5-A output without external FET; reduces BOM count and layout complexity versus controller-only solutions. |
| ±2% output voltage accuracy | Guaranteed over full temperature, line, and load range-eliminates need for post-regulation trimming in industrial power supplies. |
| External sync capability (280–400 kHz) | Allows deterministic ripple frequency placement for EMI filtering and coexistence with RF subsystems in comms equipment. |
| 260-kHz fixed internal oscillator | Optimizes inductor/capacitor sizing for cost-effective off-the-shelf magnetics; balances efficiency vs. size for 5-A applications. |
| Thermal shutdown + current limiting | Protects against sustained overload or ambient overheating; latches off until reset by cycling ON/OFF or input power. |
Applications
| Industrial Motor Drive Power Supply | Telecom Line Card Preregulator |
|---|---|
|
Use Scenario: Powers FPGA, DSP, and interface ICs on motor control boards requiring clean 5-V rail from wide-range 24/48-V DC bus. IC Role / Device Role / Timing Role: Primary step-down regulator converting unregulated bus to stable 5 V; handles 5-A peak loads during encoder sampling bursts. Use Value: High efficiency (>84% at 12-VIN/5-A) minimizes heat rise in enclosed enclosures; TO-263 thermal pad ensures reliable operation at 70°C ambient. |
Use Scenario: Supplies 5-V logic rails for multi-channel DSLAM or base station line cards where EMI must avoid sensitive RF bands. IC Role / Device Role / Timing Role: Synchronized buck converter locked to system clock; ripple frequency placed outside receive band using 320-kHz SYNC signal. Use Value: External sync eliminates beat frequencies with adjacent transceivers; ±2% tolerance ensures consistent timing margin across temperature. |
| Battery-Powered Test Equipment | Automotive Diagnostic Tool Power |
|
Use Scenario: Powers microcontroller, display, and analog front-end in portable handheld testers operating from 12–36-V Li-ion packs. IC Role / Device Role / Timing Role: Main DC-DC converter enabling battery-to-5-V conversion; ON/OFF pin controlled by MCU for deep-sleep mode. Use Value: 50-μA standby current extends battery life during idle; wide 8–40-V input accommodates pack voltage sag and charging transients. |
Use Scenario: Generates 5-V supply for OBD-II diagnostic adapters plugged into vehicle 12-V systems with high noise and load dump spikes. IC Role / Device Role / Timing Role: Robust preregulator feeding LDOs; withstands 40-V transients and operates down to 8-V cranking voltage. Use Value: 45-V absolute max input rating and built-in thermal/current protection prevent field failures during jump-start or alternator surge events. |
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 rated, 150-kHz fixed frequency, no SYNC input, higher RDS(ON) (0.16 Ω typical). | Limited to lower-current applications; unsuitable where 5-A load or EMI-controlled ripple frequency is required. | Select when cost sensitivity outweighs current/EMI requirements; verify thermal derating at 3 A in same TO-263 footprint. |
| TPS54560B | 5-A synchronous buck, 100-kHz–2.5-MHz adjustable frequency, integrated high/low-side FETs, smaller 8-pin SOIC package. | Requires external compensation; lacks fixed 5-V version-needs FB resistor network; better for space-constrained designs. | Choose for higher switching frequencies or PCB area reduction; accept added design effort for loop compensation and layout. |
Compared with LM2596S-5.0, LM2677S-5.0 delivers 67% higher current and EMI-controllable ripple; compared with TPS54560B, it offers plug-and-play 5-V regulation but occupies more board area and lacks frequency flexibility.
Availability
LM2677S-5.0 is available at Aetrix Electronics and suitable for industrial motor drives, telecom line cards, battery-powered test equipment, and automotive diagnostic tools requiring stable component supply with long-term manufacturability.
Supply support for LM2677S-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 company headquartered in Dallas, Texas, specializing in analog, embedded processing, and power management technologies with broad industrial and automotive design expertise.
The LM2677S-5.0 belongs to TI's SIMPLE SWITCHER® family-designed for ease of use in high-efficiency, medium-power DC-DC conversion where minimal external components and proven reliability are critical.
FAQ
What is the maximum input voltage rating for LM2677S-5.0?
The LM2677S-5.0 has an absolute maximum input voltage rating of 45 V, with recommended operating range from 8 V to 40 V. Exceeding 45 V risks permanent damage. For automotive applications with load dump transients, external clamping or pre-regulation is advised to keep VIN within specification during surges.
Does LM2677S-5.0 require external feedback resistors for 5-V output?
No. The LM2677S-5.0 is a fixed-output variant: its internal feedback divider is factory-trimmed for 5.0 V, so the FB pin (Pin 6) must be connected directly to the output capacitor-no external resistors are needed. This simplifies layout and improves accuracy versus adjustable versions.
How does the SYNC pin affect protection features in LM2677S-5.0?
When the SYNC pin is actively driven (280–400 kHz), current-limit frequency foldback is disabled. Under extreme short-circuit conditions, this may reduce fault robustness versus free-running mode. TI recommends verifying short-circuit behavior in final system testing if SYNC is used in safety-critical paths.
What thermal performance can be expected from LM2677S-5.0 in TO-263 package?
In the TO-263 (KTW) package with 7.4× copper area (1.0064 in²), LM2677S-5.0 achieves θJA = 26°C/W. At 5-A load and 12-V input, typical power dissipation is ~1.5 W, resulting in ~40°C junction rise above ambient-well within the –40°C to 125°C operating range without forced air.
Can LM2677S-5.0 operate with only ceramic output capacitors?
Yes. LM2677S-5.0 supports ceramic output capacitors, provided total ESR is ≥13 mΩ (per datasheet Figure 12/13). Use parallel ceramics or add small series resistance if ESR falls below this threshold to ensure loop stability and prevent oscillation at light loads.
LM2677S-5.0 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- TO-263-8, D2PAK (7 Leads + Tab), TO-263CA
- Packaging:
- Tube
- 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:
- TO-263 (DDPAK-7)
LM2677S-5.0 FAQ
1.How can I place an order for LM2677S-5.0 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2677S-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 LM2677S-5.0 reliable?
The price and inventory of LM2677S-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 LM2677S-5.0 is usually 5 days.
3.What payment methods are accepted for LM2677S-5.0?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2677S-5.0 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2677S-5.0?
LM2677S-5.0 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2677S-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 LM2677S-5.0?
For technical support, including LM2677S-5.0 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2677S-5.0 requirements.
6.How does Aetrix verify that LM2677S-5.0 is sourced from the original manufacturer or authorized distributors?
All LM2677S-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 LM2677S-5.0 meets industry standards.
7.What is the process for return or replacement of LM2677S-5.0?
All LM2677S-5.0 units undergo pre-shipment inspection (PSI). If there is an issue with LM2677S-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 LM2677S-5.0 part is unused and in its original packaging.
Return procedure for LM2677S-5.0:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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