My Inquiry
My Account
Texas Instruments LM2677T-12
- Part No.:
- LM2677T-12
- Manufacturer:
- Texas Instruments
- Package:
- TO-220-7 Formed Leads
- Datasheet:
-
LM2677T-12.pdf
- Description:
- IC REG BUCK 12V 5A TO220-7
- Quantity:
- Payment:
- Shipping:
Inventory:4,280
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM2677T-12 from Texas Instruments is a monolithic step-down (buck) DC/DC voltage regulator with integrated 100 mΩ DMOS power switch, delivering up to 5A output current at fixed 12V output, operating from 15V to 40V input, achieving up to 92% efficiency at 24VIN/5A, and used in high-efficiency pre-regulator and battery-charger applications.
For engineers reviewing the LM2677T-12 datasheet, LM2677T-12 pinout, LM2677T-12 application, or LM2677T-12 equivalent, key selection criteria include its fixed 12V output, 260 kHz internal oscillator, ±2% output tolerance over line/load/temperature, ON/OFF control with 50 μA standby current, and external sync capability from 280 kHz to 400 kHz.
Technical Context
The LM2677T-12 implements a current-mode PWM buck controller with internal 260 kHz fixed-frequency oscillator and optional external synchronization. Its DMOS power switch features 0.12 Ω typical RDS(ON), enabling high-efficiency operation across 15V–40V input range while maintaining 12V ±2% regulation under 100 mA–5 A load.
Thermal protection includes built-in thermal shutdown and current limiting; ON/OFF pin enables low-quiescent 50 μA standby mode. The feedback pin accepts direct connection to output for fixed-voltage operation, eliminating external resistors.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 12 V, ±2% tolerance over full line, load, and temperature (−40°C to +125°C) |
| Input Voltage Range | 15 V to 40 V - minimum input raised vs. other variants to ensure stable 12V regulation |
| Max Output Current | 5 A - continuous DC load capability with proper thermal management |
| Efficiency | Up to 92% at VIN = 24 V, IOUT = 5 A - enables reduced heat sink requirements in high-power systems |
| Switch RDS(ON) | 0.12 Ω typical - minimizes conduction loss in high-current buck stage |
| Oscillator Frequency | 260 kHz fixed internal frequency, or externally synchronizable from 280 kHz to 400 kHz - supports EMI control and multi-rail timing alignment |
| Standby Current | 50 μA when ON/OFF pin ≤ 0.8 V - enables ultra-low-power system sleep modes |
Pinout & Package
LM2677T-12 is available in TO-220 (NDZ0007B) and DDPAK/TO-263 (KTW0007B) packages. Thermal resistance θJA ranges from 26°C/W (KTW with 7.4× copper area) to 65°C/W (NDZ no heatsink), supporting scalable thermal design.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pin 2) | Input supply connection | Accepts 15–40 V DC; requires local bypass capacitor for stability and transient response |
| VSW (Pin 1) | Switch node | Drives external inductor; swings from VIN to ~−0.5 V during off-time via Schottky catch diode |
| CBOOST (Pin 3) | Bootstrap capacitor terminal | Connects 0.01 μF ceramic cap to VSW to gate-drive internal MOSFET above VIN for low RDS(ON) |
| GND (Pin 4) | Power and signal ground reference | Must be low-inductance plane; separates power and small-signal return paths for noise immunity |
| SYNC (Pin 5) | External clock input | Accepts TTL/CMOS clock (280–400 kHz); resets internal oscillator on rising edge for ripple frequency control |
| FB (Pin 6) | Feedback input | Internally connected to 12V divider - direct output tie required; no external resistors needed |
| ON/OFF (Pin 7) | Enable/disable control | Pulled up internally; ≤0.8 V disables regulator, reducing quiescent current to 50 μA |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 100 mΩ DMOS switch | Enables 5A output without external FET, reducing BOM count and layout complexity |
| ±2% output voltage accuracy | Guaranteed over full −40°C to +125°C junction temperature, line, and load - eliminates post-production trimming |
| 260 kHz fixed-frequency PWM | Provides predictable EMI profile and simplifies filter design vs. variable-frequency alternatives |
| External sync capability (280–400 kHz) | Allows precise ripple frequency positioning for multi-rail systems and compliance with spectral masks |
| Thermal shutdown & current limit | Protects against sustained overload or ambient overheating without external circuitry |
Applications
| Battery Charger Systems | Industrial Power Pre-regulation |
|---|---|
Use Scenario: Charging 12V lead-acid or LiFePO4 battery banks from wide-range DC sources (e.g., solar arrays or vehicle alternators). IC Role / Device Role / Timing Role: Primary step-down regulator delivering regulated 12V at up to 5A, with ON/OFF control enabling charge-stage sequencing. Use Value: High 92% efficiency at 24VIN/5A reduces thermal stress and extends battery runtime in energy-constrained systems. | Use Scenario: Generating stable 12V intermediate rail for downstream LDOs or analog circuitry in programmable logic controllers (PLCs). IC Role / Device Role / Timing Role: High-current pre-regulator converting unregulated 24V or 36V industrial bus to clean 12V supply. Use Value: ±2% output tolerance and built-in current limiting ensure reliable operation under varying load transients and fault conditions. |
| Communications Equipment Power | Radio Transceiver Power Supply |
Use Scenario: Providing 12V bias to RF front-end modules and baseband processors in cellular infrastructure equipment. IC Role / Device Role / Timing Role: Fixed-output buck regulator with SYNC input synchronized to system clock to suppress switching noise in sensitive receive paths. Use Value: External sync (280–400 kHz) enables deterministic ripple placement outside critical IF bands, easing filtering requirements. | Use Scenario: Powering HF/VHF transceivers requiring low-noise, high-reliability 12V supply in mobile or portable radios. IC Role / Device Role / Timing Role: Main DC/DC converter with thermal shutdown and wide 15–40V input range accommodating vehicle battery fluctuations. Use Value: −40°C to +125°C operating range and robust current-limit protection ensure uninterrupted operation in harsh environmental conditions. |
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, identical 12V fixed output, but rated for 3A max output current and higher RDS(ON) (0.22 Ω typical) | Suitable for lower-power 12V rails where 5A headroom is unnecessary | Select LM2678-12 only if thermal budget or cost constraints justify reduced current capability |
| TPS54560B | Adjustable output (1.21V–36V), 60V max input, 5A current, 100 kHz–2.5 MHz sync range, smaller SOIC-8 package | Requires external feedback resistors; better suited for designs needing flexibility or higher input voltage | Choose TPS54560B when adjustable output, wider input range, or higher-frequency sync is required |
Compared with LM2677T-12, LM2678-12 offers identical functionality at reduced current rating and cost, while TPS54560B provides greater design flexibility and input voltage margin at the expense of fixed-output simplicity and thermal footprint.
Availability
LM2677T-12 is available at Aetrix Electronics and suitable for battery charger systems, industrial power pre-regulation, communications equipment power, and radio transceiver power supply requiring stable component supply, long-term lifecycle support, and consistent parametric performance.
Supply support for LM2677T-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 company headquartered in Dallas, Texas, specializing in analog, embedded processing, and power management ICs with broad industrial, automotive, and communications reach.
The LM2677 series belongs to TI's SIMPLE SWITCHER® family of easy-to-use, high-efficiency DC/DC regulators designed for rapid power supply implementation with minimal external components in industrial and embedded systems.
FAQ
What is the minimum input voltage required for stable operation of the LM2677T-12?
The LM2677T-12 requires a minimum input voltage of 15 V to maintain regulation at its fixed 12 V output across full load and temperature range. This is higher than the 8 V minimum for the 3.3 V and 5 V variants due to duty-cycle limitations at higher output voltages. Operation below 15 V may result in dropout or loss of regulation.
Does the LM2677T-12 require external feedback resistors to set the output voltage?
No, the LM2677T-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 must be connected directly to the output voltage node to close the regulation loop - no external components are needed for voltage setting.
Can the LM2677T-12 be synchronized to an external clock, and what is the valid frequency range?
Yes, the LM2677T-12 supports external synchronization via the SYNC pin (Pin 5). The valid input clock frequency range is 280 kHz to 400 kHz. Clock signals outside this range may cause erratic operation or failure to lock; the internal oscillator remains active if SYNC is left open-circuited at 260 kHz.
What thermal considerations apply to the LM2677T-12 in TO-220 (NDZ) versus DDPAK (KTW) packages?
In the TO-220 (NDZ0007B) package, θJA is 65°C/W with no heatsink and improves to 45°C/W with 4 in² copper; in the DDPAK (KTW0007B), θJA ranges from 56°C/W (minimal copper) to 26°C/W (7.4× copper area). For 5A operation at high ambient temperatures, KTW with ≥0.4896 in² copper is strongly recommended to maintain TJ ≤ 125°C.
How does the ON/OFF pin function, and what is the quiescent current in shutdown mode?
The ON/OFF pin (Pin 7) is internally pulled up. Driving it to ≤ 0.8 V disables the LM2677T-12, reducing total input current to 50 μA. At 25°C, the pin draws ≤ 45 μA when pulled low. This ultra-low standby current enables energy-efficient system-level power gating without external disconnect switches.
LM2677T-12 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:
- 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:
- Through Hole
- Supplier Device Package:
- TO-220-7
LM2677T-12 FAQ
1.How can I place an order for LM2677T-12 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2677T-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 LM2677T-12 reliable?
The price and inventory of LM2677T-12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2677T-12 is usually 5 days.
3.What payment methods are accepted for LM2677T-12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2677T-12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2677T-12?
LM2677T-12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2677T-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 LM2677T-12?
For technical support, including LM2677T-12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2677T-12 requirements.
6.How does Aetrix verify that LM2677T-12 is sourced from the original manufacturer or authorized distributors?
All LM2677T-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 LM2677T-12 meets industry standards.
7.What is the process for return or replacement of LM2677T-12?
All LM2677T-12 units undergo pre-shipment inspection (PSI). If there is an issue with LM2677T-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 LM2677T-12 part is unused and in its original packaging.
Return procedure for LM2677T-12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM2677T-12 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…
