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Texas Instruments LM2670T-3.3
- Part No.:
- LM2670T-3.3
- Manufacturer:
- Texas Instruments
- Package:
- TO-220-7 Formed Leads
- Datasheet:
-
LM2670T-3.3.pdf
- Description:
- IC REG BUCK 3.3V 3A TO220-7
- Quantity:
- Payment:
- Shipping:
Inventory:4,702
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Product details
Overview
LM2670T-3.3 from Texas Instruments is a monolithic 3-A step-down (buck) DC/DC voltage regulator with fixed 3.3-V output, 8–40-V input range, 260-kHz internal oscillator, ±2% output tolerance over line/load/temperature, and 150-mΩ DMOS high-side switch. It delivers high-efficiency power conversion in industrial power supplies and communications equipment.
For engineers reviewing the LM2670T-3.3 datasheet, LM2670T-3.3 pinout, LM2670T-3.3 application, or LM2670T-3.3 equivalent, key selection considerations include its 3-A continuous output capability, 50-µA standby current in shutdown mode, external sync clock support (280–400 kHz), thermal shutdown protection, and TO-263-7 package with exposed thermal pad for enhanced power dissipation.
Technical Context
The LM2670T-3.3 implements a current-mode PWM buck controller with an integrated 150-mΩ DMOS high-side switch and fixed 3.3-V feedback reference. Its 260-kHz internal oscillator enables stable operation without external timing components, while the SYNC pin allows frequency synchronization to external clocks up to 400 kHz for EMI control and spectral positioning.
It operates across –40°C to +125°C junction temperature, supports shutdown via ON/OFF pin (1.4-V threshold), and integrates current limiting (3.6–5.4 A), thermal shutdown, and soft-start functionality. The CBOOST/CB pin drives the high-side gate using a 100-nF bootstrap capacitor, enabling efficient high-side FET conduction.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3 V ±2% over full line, load, and –40°C to +125°C temperature range - ensures stable logic supply for microcontrollers and FPGAs. |
| Input Voltage Range | 8 V to 40 V - supports wide-input industrial and automotive battery-derived rails without pre-regulation. |
| Continuous Output Current | 3 A - sufficient for powering multiple digital ICs or subsystems from a single regulator stage. |
| Switching Frequency | 260 kHz (internal fixed oscillator); externally synchronizable from 280 kHz to 400 kHz - enables predictable ripple filtering and EMI management. |
| Efficiency | Up to 94% at 12-V input / 5-A load (for 12-V version); 86% typical at 12-V input / 5-A load (3.3-V version) - reduces thermal load and improves system power density. |
| Quiescent Current | 6 mA operating; 50 µA in shutdown (ON/OFF = low) - enables low-power standby modes in battery-backed systems. |
| Switch RDS(ON) | 0.15 Ω typical at 25°C - minimizes conduction loss and self-heating under full load. |
Pinout & Package
LM2670T-3.3 is packaged in TO-263-7 (KTW) with exposed thermal pad (10.10 mm × 8.89 mm body). The package provides low thermal resistance (RθJA = 26°C/W with 0.4896 in² copper) and mechanical robustness for high-power industrial applications.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (SW) | Switch output | Drain node of internal high-side DMOS switch; connects to inductor and Schottky diode cathode - carries high-frequency pulsed current and requires tight layout to minimize EMI. |
| 2 (VIN) | Input supply | Main power input (8–40 V); supplies both load path and internal bias - must be decoupled with low-ESR capacitor placed adjacent to pin. |
| 3 (CBOOST) | Bootstrap capacitor connection | Connects 100-nF ceramic capacitor to SW pin to generate gate drive voltage > VIN for full enhancement of high-side MOSFET. |
| 4 (GND) | Power ground | Primary return path for input/output capacitors and internal circuitry - must connect directly to thermal pad and low-impedance ground plane. |
| 5 (SYNC) | External sync input | Accepts TTL/CMOS clock (280–400 kHz) to override internal oscillator - used for EMI reduction and synchronized multi-rail systems. |
| 6 (FB) | Feedback input | Internally connected to 3.3-V reference; tied directly to output capacitor for fixed-output operation - no external resistors required. |
| 7 (ON/OFF) | Enable control | Active-high enable (1.4-V threshold); pulls to GND to enter 50-µA shutdown - supports remote power sequencing and system-level sleep control. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 150-mΩ DMOS high-side switch | Eliminates need for external MOSFET and gate driver, reducing BOM count and PCB area while maintaining 3-A capability. |
| ±2% output voltage tolerance | Guaranteed accuracy across –40°C to +125°C, 8–40-V input, and 100-mA to 3-A load - meets tight regulation requirements for digital core supplies. |
| 260-kHz fixed-frequency PWM | Enables consistent filter design and predictable EMI profile without external timing components or loop compensation tuning. |
| 50-µA shutdown quiescent current | Supports ultra-low-power standby states in battery-powered or energy-conscious systems without auxiliary LDOs. |
| Thermal shutdown and current limiting | Protects against overload, short-circuit, and overheating conditions without external sensing circuitry - enhances system reliability. |
Applications
| Industrial Power Supply | Communications Equipment |
|---|---|
|
Use Scenario: Providing primary 3.3-V rail for PLC I/O modules powered from 24-V DC bus. IC Role / Device Role / Timing Role: Primary step-down regulator converting unregulated 24-V field power to clean, regulated 3.3-V for microcontroller, ADC, and interface ICs. Use Value: Delivers 3 A continuously with <2% output variation despite 24-V bus fluctuations and ambient temperatures up to +70°C. |
Use Scenario: Generating 3.3-V supply for RF transceiver baseband section in point-to-point radio units. IC Role / Device Role / Timing Role: Synchronized buck regulator locked to system clock (via SYNC pin) to position switching noise away from sensitive IF bands. Use Value: Enables deterministic EMI placement and <10-mVpp output ripple when paired with low-ESR tantalum output capacitors. |
| Battery Charger Auxiliary Rail | Test & Measurement Instrumentation |
|
Use Scenario: Powering MCU and display logic in lithium-ion battery charger with 12–36-V adapter input. IC Role / Device Role / Timing Role: Pre-regulator supplying 3.3-V to charging controller and status indicators during variable-input charging cycles. Use Value: Maintains regulation down to 8-V input, allowing operation even as adapter voltage sags under heavy load or low-line conditions. |
Use Scenario: Supplying precision 3.3-V reference for data acquisition front-end in portable oscilloscopes. IC Role / Device Role / Timing Role: Low-noise, thermally stable DC/DC stage feeding analog signal chain - minimized by thermal pad mounting and low-RDS(ON). Use Value: Achieves <0.5% load regulation and <100-µV RMS output noise (measured with 20-MHz bandwidth) under 2-A dynamic load steps. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2671-3.3 | Pin-compatible but uses external N-channel MOSFET; lacks integrated switch - requires additional gate driver and discrete FET. | Suitable only where higher efficiency (>95%) at light loads or custom FET selection is needed; not drop-in. | Select LM2671-3.3 only if discrete FET optimization is required; otherwise LM2670T-3.3 offers lower BOM cost and simpler layout. |
| TPS54332DR | 3-A synchronous buck with 4.5–28-V input, 3.3-V fixed output, 1-MHz switching, and integrated high/low-side FETs - smaller solution size but narrower input range. | Better suited for compact, low-input-voltage designs (e.g., 12-V systems); not rated for 40-V transients or industrial 24-V bus surges. | Choose TPS54332DR for space-constrained 12-V applications; LM2670T-3.3 remains preferred for 24/36-V industrial inputs requiring ruggedness. |
Compared with LM2671-3.3, LM2670T-3.3 eliminates external FET and driver complexity while delivering proven 3-A performance in harsh environments; versus TPS54332DR, it trades higher-frequency operation for wider input range and superior transient robustness - making it the optimal choice for 24-V+ industrial and telecom infrastructure.
Availability
LM2670T-3.3 is available at Aetrix Electronics and suitable for industrial power supplies, communications equipment, battery charger auxiliary rails, and test & measurement instrumentation requiring stable component supply across extended temperature and voltage ranges.
Supply support for LM2670T-3.3 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 LM2670 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 guaranteed performance across industrial temperature and voltage extremes.
FAQ
What is the maximum input voltage rating for LM2670T-3.3?
The absolute maximum input voltage for LM2670T-3.3 is 45 V, with recommended continuous operation between 8 V and 40 V. Exceeding 40 V may trigger internal overvoltage protection or reduce long-term reliability; sustained operation above 40 V is not advised per TI's recommended operating conditions.
Does LM2670T-3.3 require external feedback resistors?
No, LM2670T-3.3 does not require external feedback resistors. As a fixed 3.3-V output variant, it contains internal resistor dividers connected to the FB pin; the FB pin must be connected directly to the output capacitor's positive terminal for proper regulation.
Can LM2670T-3.3 synchronize to an external clock?
Yes, LM2670T-3.3 supports external synchronization via the SYNC pin (Pin 5). It accepts TTL/CMOS-compatible clocks from 280 kHz to 400 kHz, enabling precise control of switching frequency for EMI reduction and multi-rail coherence - but disables current-limit foldback when active.
What thermal performance can be expected from LM2670T-3.3 in TO-263 package?
In the TO-263-7 (KTW) package with 0.4896 in² copper area on the PCB, LM2670T-3.3 achieves RθJA = 35°C/W (typical) and RθJC = 2°C/W. At 3-A load and 12-V input, junction temperature rise is ~105°C above ambient - confirming suitability for industrial environments up to +70°C ambient with proper heatsinking.
Is LM2670T-3.3 RoHS compliant and lead-free?
Yes, LM2670T-3.3 is RoHS compliant and lead-free per TI's official packaging documentation. The TO-263-7 package uses matte tin (Sn) lead finish and meets JEDEC J-STD-020 moisture sensitivity level 3 (MSL-3), supporting standard reflow profiles without special handling.
LM2670T-3.3 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):
- 3.3V
- Voltage - Output (Max):
- -
- 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
LM2670T-3.3 FAQ
1.How can I place an order for LM2670T-3.3 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2670T-3.3 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 LM2670T-3.3 reliable?
The price and inventory of LM2670T-3.3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2670T-3.3 is usually 5 days.
3.What payment methods are accepted for LM2670T-3.3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2670T-3.3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2670T-3.3?
LM2670T-3.3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2670T-3.3 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 LM2670T-3.3?
For technical support, including LM2670T-3.3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2670T-3.3 requirements.
6.How does Aetrix verify that LM2670T-3.3 is sourced from the original manufacturer or authorized distributors?
All LM2670T-3.3 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 LM2670T-3.3 meets industry standards.
7.What is the process for return or replacement of LM2670T-3.3?
All LM2670T-3.3 units undergo pre-shipment inspection (PSI). If there is an issue with LM2670T-3.3, 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 LM2670T-3.3 part is unused and in its original packaging.
Return procedure for LM2670T-3.3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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