My Inquiry
My Account
Texas Instruments LM2677T-3.3/NOPB
- Part No.:
- LM2677T-3.3/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- TO-220-7 Formed Leads
- Datasheet:
-
LM2677T-3.3/NOPB.pdf
- Description:
- IC REG BUCK 3.3V 5A TO220-7
- Quantity:
- Payment:
- Shipping:
Inventory:3,136
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM2677T-3.3/NOPB from Texas Instruments is a monolithic 5-A step-down (buck) DC/DC voltage regulator with fixed 3.3-V output, 8 V to 40 V input range, 260-kHz internal oscillator, 100-mΩ DMOS switch, and ±2% output voltage tolerance over line/load/temperature. It delivers high-efficiency power conversion in industrial power supplies and battery-charged systems.
For engineers reviewing the LM2677T-3.3/NOPB datasheet, LM2677T-3.3/NOPB pinout, LM2677T-3.3/NOPB application, or LM2677T-3.3/NOPB equivalent, key selection criteria include input voltage range compatibility, thermal performance in TO-263 package, synchronous clock capability up to 400 kHz, ON/OFF control interface, and fixed-output regulation stability under 5-A load.
Technical Context
The LM2677T-3.3/NOPB implements a current-mode PWM buck controller with integrated 100-mΩ DMOS high-side switch and internal 1.21-V reference. Its 260-kHz fixed-frequency oscillator enables predictable ripple frequency and simplifies EMI filtering; external SYNC input (280–400 kHz) allows precise clock alignment for multi-rail systems.
Operation includes thermal shutdown, cycle-by-cycle current limiting (6.1–8.75 A), and ON/OFF control with 50-μA standby quiescent current. Feedback is internally connected for 3.3-V fixed output-no external divider required-ensuring ±2% regulation across –40°C to 125°C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3 V ±2% over full line, load, and temperature (–40°C to 125°C) |
| Input Voltage Range | 8 V to 40 V - supports wide-range industrial and automotive battery inputs |
| Max Output Current | 5 A continuous - enables single-regulator solutions for mid-power embedded systems |
| Switch RDS(ON) | 0.12 Ω typical at 25°C - minimizes conduction loss and improves efficiency above 90% |
| Oscillator Frequency | 260 kHz fixed internal frequency - sets baseline ripple frequency and filter component sizing |
| SYNC Input Range | 280 kHz to 400 kHz - allows synchronized switching in multi-converter systems to avoid beat frequencies |
| Standby Quiescent Current | 50 μA max - enables low-power shutdown mode without auxiliary bias circuitry |
Pinout & Package
LM2677T-3.3/NOPB is packaged in TO-263 (KTW) - a 7-pin surface-mount thermally enhanced package with exposed thermal pad (10.16 mm × 8.69 mm body size). The DAP must be soldered to a PCB ground plane for optimal thermal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VSW (Pin 1) | Switch node output | Drives external inductor; swings between VIN and ~–0.5 V during off-time - requires low-inductance layout to minimize ringing |
| VIN (Pins 2, 3) | Power input | Connects to high-current input source and bulk capacitor; dual pins reduce trace resistance and improve thermal path |
| CB (Pin 4) | Bootstrap capacitor connection | Requires 0.01-μF ceramic capacitor to VSW - enables gate drive above VIN for full MOSFET enhancement |
| GND (Pin 5) | Power ground | Main return path for input/output currents; must tie directly to thermal pad and low-impedance ground plane |
| SYNC (Pin 6) | External clock input | Accepts TTL/CMOS signal (280–400 kHz); open-circuit defaults to 260-kHz internal oscillator |
| ON/OFF (Pin 7) | Enable control input | Logic-high (>1.4 V) enables regulation; logic-low (<0.8 V) disables with 50-μA standby draw |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 100-mΩ DMOS switch | Eliminates need for external high-side FET and driver, reducing BOM count and layout complexity |
| Fixed 3.3-V output configuration | Internal feedback network removes external resistor divider - improves accuracy and reduces board space |
| External SYNC capability (280–400 kHz) | Enables deterministic ripple frequency positioning for EMI-sensitive applications like radio transceivers |
| Thermal shutdown + current limit protection | Provides autonomous fault recovery without external monitoring circuitry - enhances system reliability |
| 50-μA standby quiescent current | Supports always-on subsystems with minimal battery drain during sleep modes |
Applications
| Industrial PLC Power Supply | Battery-Charged Portable Instrument |
|---|---|
|
Use Scenario: Converts 24-V DC bus to stable 3.3-V rail for microcontroller, ADC, and communication ICs in programmable logic controllers. IC Role / Device Role / Timing Role: Primary step-down regulator supplying core logic voltage with tight regulation and high PSRR against bus transients. Use Value: Delivers 5-A peak current with ±2% output tolerance across –40°C to 85°C ambient - ensures deterministic MCU operation without brownout. |
Use Scenario: Regulates variable 9–36-V lead-acid or LiFePO₄ battery pack to clean 3.3-V supply for data acquisition and wireless modules. IC Role / Device Role / Timing Role: High-efficiency preregulator preceding LDOs, minimizing heat generation in sealed enclosures. Use Value: Achieves >90% efficiency at 5-A load from 12-V input - extends runtime by reducing power loss versus linear alternatives. |
| Communications Baseband Module | Automotive Infotainment Core Rail |
|
Use Scenario: Powers FPGA and DSP cores in cellular baseband units requiring synchronized switching to avoid interference with RF sections. IC Role / Device Role / Timing Role: Synchronized buck converter locked to system clock domain via SYNC pin. Use Value: External 350-kHz SYNC input fixes ripple frequency - enables consistent EMI filter design and avoids heterodyne mixing in adjacent bands. |
Use Scenario: Generates 3.3-V main logic rail from vehicle 12-V battery in head unit or telematics control unit. IC Role / Device Role / Timing Role: Automotive-grade DC/DC regulator handling cold-crank (6.5-V) and load-dump (40-V) transients. Use Value: 8–40-V input range and thermal shutdown protect against automotive electrical anomalies - meets ISO 7637-2 pulse requirements. |
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-3.3/NOPB | Same pinout and function but rated for 3-A output current; lower RDS(ON) (85 mΩ) and higher efficiency at light loads | Suitable for ≤3-A applications where thermal margin is constrained; not rated for 5-A continuous operation | Select when full 5-A capability is unnecessary and board space/thermal budget favors smaller solution size |
| TPS54560BQDDARQ1 | Automotive-qualified (AEC-Q100 Grade 1), 60-V max input, adjustable output, 5-A rating, integrated soft-start and UVLO | Designed for automotive environments with extended temperature and qualification requirements; requires external feedback resistors | Choose for automotive production programs needing ASIL-ready components and wider input transient tolerance |
Compared with LM2677T-3.3/NOPB, LM2678T-3.3/NOPB offers reduced current capacity but improved light-load efficiency, while TPS54560BQDDARQ1 adds automotive qualification and flexibility at the cost of fixed-output simplicity and external compensation.
Availability
LM2677T-3.3/NOPB is available at Aetrix Electronics and suitable for industrial PLC power supplies, battery-charged portable instruments, communications baseband modules, and automotive infotainment core rails requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LM2677T-3.3/NOPB 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, delivering analog and embedded processing solutions across industrial, automotive, and personal electronics markets.
The LM2677 series belongs to TI's SIMPLE SWITCHER® family - designed specifically for ease-of-use in non-isolated DC/DC buck conversion, emphasizing minimal external components, robust protection, and high efficiency in demanding power applications.
FAQ
What is the maximum input voltage rating for LM2677T-3.3/NOPB?
The absolute maximum input voltage for LM2677T-3.3/NOPB is 45 V, but the recommended operating range is 8 V to 40 V. Operation beyond 40 V risks exceeding safe operating area limits and may trigger internal protection circuits. For automotive cold-crank scenarios down to 6 V, the device will cease regulation but remains undamaged if duration is within datasheet-specified transient limits.
Does LM2677T-3.3/NOPB require external feedback resistors?
No, LM2677T-3.3/NOPB does not require external feedback resistors. It is a fixed-output variant with internal resistor divider configured for 3.3 V, so the FB pin is internally connected to the output stage. External resistors are only needed for the adjustable version (LM2677-ADJ); adding them to LM2677T-3.3/NOPB would disrupt regulation.
How is thermal performance affected by PCB layout for LM2677T-3.3/NOPB?
Thermal performance of LM2677T-3.3/NOPB depends critically on PCB copper area connected to its exposed thermal pad (DAP). With 0.136 in² copper, θJA is 56°C/W; increasing to 1.0064 in² reduces it to 26°C/W. Poor thermal pad soldering or insufficient ground plane area causes junction temperature rise, potentially triggering thermal shutdown at 5-A load in enclosed environments.
Can LM2677T-3.3/NOPB synchronize to an external clock below 260 kHz?
No, LM2677T-3.3/NOPB cannot synchronize to an external clock below 260 kHz. The SYNC input requires a frequency between 280 kHz and 400 kHz. Applying a signal below 280 kHz may cause erratic switching or failure to lock, as the internal ramp oscillator resets on each sync edge and requires minimum timing margins to maintain stable PWM operation.
What protection features are built into LM2677T-3.3/NOPB?
LM2677T-3.3/NOPB integrates cycle-by-cycle current limiting (6.1–8.75 A), thermal shutdown (typically 165°C), and ON/OFF-controlled 50-μA standby mode. It does not include output overvoltage protection or reverse-polarity input protection - those must be implemented externally using TVS diodes or ideal diodes if required by the application.
LM2677T-3.3/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- TO-220-7 Formed Leads
- Packaging:
- Tube
- Product Status:
- Active
- 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):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 5A
- 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
LM2677T-3.3/NOPB FAQ
1.How can I place an order for LM2677T-3.3/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2677T-3.3/NOPB 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 LM2677T-3.3/NOPB reliable?
The price and inventory of LM2677T-3.3/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2677T-3.3/NOPB is usually 5 days.
3.What payment methods are accepted for LM2677T-3.3/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2677T-3.3/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2677T-3.3/NOPB?
LM2677T-3.3/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2677T-3.3/NOPB 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 LM2677T-3.3/NOPB?
For technical support, including LM2677T-3.3/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2677T-3.3/NOPB requirements.
6.How does Aetrix verify that LM2677T-3.3/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2677T-3.3/NOPB 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 LM2677T-3.3/NOPB meets industry standards.
7.What is the process for return or replacement of LM2677T-3.3/NOPB?
All LM2677T-3.3/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2677T-3.3/NOPB, 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 LM2677T-3.3/NOPB part is unused and in its original packaging.
Return procedure for LM2677T-3.3/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM2677T-3.3/NOPB Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
