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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - DC DC Switching Regulators

Texas Instruments LM2670SD-3.3

Name: LM2670SD-3.3
Brand: Texas Instruments
SKU: LM2670SD-3.3
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LM2670SD-3.3

Manufacturer:: Texas Instruments

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: 14-VDFN Exposed Pad

Datasheet:: LM2670SD-3.3.pdf

Description:: IC REG BUCK 3.3V 3A 14VSON

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Product details

Overview

LM2670SD-3.3 from Texas Instruments is a monolithic 3-A synchronous 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 50-µA standby current in shutdown mode. It integrates a 150-mΩ DMOS high-side switch and supports external clock synchronization for EMI-sensitive communications and radio equipment.

For engineers reviewing the LM2670SD-3.3 datasheet, LM2670SD-3.3 pinout, LM2670SD-3.3 application, or LM2670SD-3.3 equivalent, key selection criteria include its fixed 3.3-V output accuracy, thermal shutdown and current limiting protection, SYNC capability for ripple frequency control, and compatibility with standard off-the-shelf inductors and Schottky diodes in high-efficiency (>90%) power conversion designs.

Technical Context

The LM2670SD-3.3 implements a PWM-controlled buck topology using an integrated high-side DMOS FET with 0.15-Ω typical R_DS(ON), enabling up to 3-A continuous output current. Its internal 260-kHz oscillator sets switching frequency, while the SYNC pin accepts external clocks from 280 kHz to 400 kHz to precisely position output ripple spectrum-critical for RF and communication systems.

Operation includes active-mode regulation via feedback loop referencing the 3.3-V output directly to the FB pin (no external divider), and shutdown mode triggered by pulling the ON/OFF pin below 0.8 V, reducing quiescent current to 50 µA. Built-in thermal shutdown, cycle-by-cycle current limiting (3.8–5.25 A), and under-voltage lockout ensure robust operation 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 (8–40 V), load (100 mA–5 A), and temperature (–40°C to 125°C) - ensures stable logic supply without external resistors.
Input voltage range	8 V to 40 V - supports wide industrial, automotive, and telecom input rails including unregulated 12-V and 24-V systems.
Switching frequency	260 kHz fixed internal oscillator (225–280 kHz over temp); sync-capable up to 400 kHz - enables predictable EMI filtering and small passive component sizing.
Efficiency	Up to 94% at 12-V input / 5-A load (3.3-V version) - minimizes thermal stress and improves system power density.
Quiescent current	50 µA in shutdown (ON/OFF = 0 V) - extends battery life in always-on or low-power standby applications.
Current limit	3.8–5.25 A typical over temperature - provides reliable short-circuit protection without external sensing.
R_DS(ON)	0.15 Ω typical - reduces conduction loss and improves efficiency at high load currents.

Pinout & Package

LM2670SD-3.3 is packaged in a 7-pin TO-263 (KTW) surface-mount package with exposed thermal pad (10.10 mm × 8.89 mm), optimized for high-current thermal dissipation on PCBs with copper area.

Pin/Terminal	Circuit Role	Design Meaning
1 (SW)	Switch output	Drain of internal high-side DMOS FET - connects to inductor and Schottky diode cathode; switches between VIN and ~–0.4 V during OFF time.
2 (VIN)	Input supply	Main power input (8–40 V); supplies internal bias and high-side switch - requires low-ESR bypass capacitor placed adjacent to pin.
3 (CBOOST)	Bootstrap capacitor	Connects 100-nF ceramic capacitor to SW pin - generates gate drive voltage >VIN to fully enhance high-side FET and minimize R_DS(ON).
4 (GND)	Power ground	Common return for input/output capacitors, thermal pad, and internal circuitry - must be tied to low-impedance PCB ground plane.
5 (SYNC)	External clock input	Accepts TTL/CMOS clock (280–400 kHz) to override internal oscillator - enables precise ripple frequency control for EMI compliance.
6 (FB)	Feedback sense	Direct connection to 3.3-V output - internal resistor divider sets regulation point; no external components required for fixed-output version.
7 (ON/OFF)	Enable control	Logic-level enable: >1.4 V = active, <0.8 V = shutdown - allows system-level power sequencing and low-quiescent sleep modes.

Key Features

Feature	Design Value
Integrated 150-mΩ high-side DMOS switch	Enables compact 3-A buck design without external MOSFETs or gate drivers - reduces BOM count and layout complexity.
±2% output voltage tolerance	Guaranteed across full operating range - eliminates need for post-regulation LDOs in noise-sensitive digital logic supplies.
External SYNC capability (280–400 kHz)	Allows deterministic placement of switching noise in frequency domain - essential for meeting CISPR-22/32 conducted EMI limits in comms gear.
50-µA shutdown current	Supports ultra-low-power system states - e.g., maintaining 3.3-V rail for real-time clocks or wake-on-LAN circuitry during host sleep.
Built-in thermal shutdown & current limiting	Provides autonomous fault protection without external monitoring ICs - enhances reliability in unattended industrial or remote deployments.

Applications

Industrial PLC I/O Power	Telecom Line Card Bias
Use Scenario: Providing isolated 3.3-V logic supply for digital I/O modules in programmable logic controllers operating from 24-V DC field bus. IC Role / Device Role / Timing Role: Primary step-down regulator converting 24-V input to clean, regulated 3.3-V rail for microcontrollers, FPGA configuration, and level-shifted sensor interfaces. Use Value: Delivers 3-A continuous current with <1% output ripple and ±2% accuracy - ensures reliable operation of high-speed digital logic under varying load transients.	Use Scenario: Generating stable 3.3-V bias for Ethernet PHYs, SerDes, and management processors on carrier-grade line cards powered from -48-V DC backplane. IC Role / Device Role / Timing Role: Pre-regulator stage stepping down intermediate 12-V rail to 3.3-V, synchronized to system clock to suppress beat frequencies in high-speed data links. Use Value: SYNC pin enables alignment of switching ripple with system timing reference - prevents jitter injection into 10/25/100-Gbps serial lanes.
Automotive Infotainment Core Supply	Point-of-Load for FPGA/ASIC
Use Scenario: Powering ARM-based application processors and DDR memory interfaces in vehicle head units supplied from 9–16-V battery rail with cold-crank dips. IC Role / Device Role / Timing Role: High-efficiency buck converter with wide 8–40-V input range handling battery transients, delivering 3.3-V core voltage with fast transient response. Use Value: 260-kHz fixed frequency and internal compensation simplify layout - meets AEC-Q100 stress requirements when paired with automotive-grade passives.	Use Scenario: Local 3.3-V supply for FPGA configuration banks and I/O banks in test equipment or edge AI accelerators requiring tight voltage margins. IC Role / Device Role / Timing Role: Point-of-load regulator placed near FPGA BGA package, minimizing IR drop and noise coupling via short traces and local bulk capacitance. Use Value: 0.15-Ω R_DS(ON) and 3-A capability support dynamic current steps up to 2 A/µs - maintains <±30 mV droop during logic state transitions.

Industrial PLC I/O Power

Telecom Line Card Bias

Use Scenario: Providing isolated 3.3-V logic supply for digital I/O modules in programmable logic controllers operating from 24-V DC field bus.

IC Role / Device Role / Timing Role: Primary step-down regulator converting 24-V input to clean, regulated 3.3-V rail for microcontrollers, FPGA configuration, and level-shifted sensor interfaces.

Use Value: Delivers 3-A continuous current with <1% output ripple and ±2% accuracy - ensures reliable operation of high-speed digital logic under varying load transients.

Use Scenario: Generating stable 3.3-V bias for Ethernet PHYs, SerDes, and management processors on carrier-grade line cards powered from -48-V DC backplane.

IC Role / Device Role / Timing Role: Pre-regulator stage stepping down intermediate 12-V rail to 3.3-V, synchronized to system clock to suppress beat frequencies in high-speed data links.

Use Value: SYNC pin enables alignment of switching ripple with system timing reference - prevents jitter injection into 10/25/100-Gbps serial lanes.

Automotive Infotainment Core Supply

Point-of-Load for FPGA/ASIC

Use Scenario: Powering ARM-based application processors and DDR memory interfaces in vehicle head units supplied from 9–16-V battery rail with cold-crank dips.

IC Role / Device Role / Timing Role: High-efficiency buck converter with wide 8–40-V input range handling battery transients, delivering 3.3-V core voltage with fast transient response.

Use Value: 260-kHz fixed frequency and internal compensation simplify layout - meets AEC-Q100 stress requirements when paired with automotive-grade passives.

Use Scenario: Local 3.3-V supply for FPGA configuration banks and I/O banks in test equipment or edge AI accelerators requiring tight voltage margins.

IC Role / Device Role / Timing Role: Point-of-load regulator placed near FPGA BGA package, minimizing IR drop and noise coupling via short traces and local bulk capacitance.

Use Value: 0.15-Ω R_DS(ON) and 3-A capability support dynamic current steps up to 2 A/µs - maintains <±30 mV droop during logic state transitions.

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down regulator applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
LM2671SD-3.3	Same architecture but lower 2.5-A current rating and 150-kHz switching frequency - higher inductor size, lower efficiency at full load.	Suitable for cost-sensitive, lower-current applications where 3-A peak is not required and board space permits larger magnetics.	Select LM2671SD-3.3 only if load current remains ≤2.5 A and EMI constraints allow lower-frequency operation.
TPS54332DDAR	3-A synchronous buck with 2.95–6.0-V input, 3.3-V fixed output, 1-MHz switching, and integrated FETs - incompatible input voltage range.	Applicable only in low-input systems (e.g., 5-V rail); cannot replace LM2670SD-3.3 in 12-/24-V industrial or automotive designs.	Choose TPS54332DDAR only for 5-V input systems requiring higher switching frequency and smaller passives - not a direct functional substitute.

Compared with LM2671SD-3.3, the LM2670SD-3.3 delivers higher current capability and better efficiency at full load; versus TPS54332DDAR, it supports wide-input industrial rails but lacks MHz-frequency operation - making LM2670SD-3.3 the optimal choice for 8–40-V, 3-A, EMI-controlled applications.

Availability

LM2670SD-3.3 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.

Supply support for LM2670SD-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 buck regulators with minimal external components and proven performance in harsh environments.

FAQ

What is the maximum output current supported by the LM2670SD-3.3?

The LM2670SD-3.3 is rated for up to 3-A continuous output current under recommended operating conditions (T_J ≤ 125°C, adequate PCB copper). Its current limit is specified from 3.8 A to 5.25 A over temperature, providing headroom for transient peaks. Actual achievable current depends on thermal design - the TO-263 package requires proper copper area and vias to sustain full load without thermal shutdown.

Does the LM2670SD-3.3 require external feedback resistors to set the 3.3-V output?

No. The LM2670SD-3.3 is a fixed-output variant - internal precision resistors configure the feedback network for exactly 3.3 V. The FB pin must be connected directly to the output capacitor node; no external resistors are needed, simplifying layout and improving accuracy versus adjustable versions subject to resistor tolerance errors.

Can the LM2670SD-3.3 synchronize to an external clock, and what are the valid frequency ranges?

Yes, the LM2670SD-3.3 supports external synchronization via the SYNC pin (Pin 5). Valid input clock frequencies range from 280 kHz to 400 kHz - strictly higher than the internal oscillator's maximum of 280 kHz. Clocks outside this band may cause erratic operation or loss of regulation; TTL- or CMOS-compatible signals with 50% duty cycle are recommended.

What protection features are built into the LM2670SD-3.3?

The LM2670SD-3.3 integrates thermal shutdown, cycle-by-cycle current limiting, and under-voltage lockout. It also features an ON/OFF pin that reduces quiescent current to 50 µA in shutdown. These protections operate autonomously without external components - ensuring safe operation during overload, overtemperature, or input brownout events in mission-critical systems.

Is the LM2670SD-3.3 pin-compatible with other members of the LM2670 family?

Yes - all LM2670 variants (including LM2670SD-3.3, LM2670SD-5.0, LM2670SD-12, and LM2670MX-ADJ) share identical 7-pin TO-263 (KTW) pinout and package footprint. This enables single PCB design reuse across multiple output voltages, reducing NRE costs and accelerating development for multi-rail power systems.

LM2670SD-3.3 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):: 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:: Surface Mount

Supplier Device Package:: 14-VSON (5x6)

LM2670SD-3.3 FAQ

1.How can I place an order for LM2670SD-3.3 through Aetrix?

Please submit a Request for Quotation (RFQ) for LM2670SD-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 LM2670SD-3.3 reliable?

The price and inventory of LM2670SD-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 LM2670SD-3.3 is usually 5 days.

3.What payment methods are accepted for LM2670SD-3.3?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2670SD-3.3 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LM2670SD-3.3?

LM2670SD-3.3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LM2670SD-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 LM2670SD-3.3?

For technical support, including LM2670SD-3.3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2670SD-3.3 requirements.

6.How does Aetrix verify that LM2670SD-3.3 is sourced from the original manufacturer or authorized distributors?

All LM2670SD-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 LM2670SD-3.3 meets industry standards.

7.What is the process for return or replacement of LM2670SD-3.3?

All LM2670SD-3.3 units undergo pre-shipment inspection (PSI). If there is an issue with LM2670SD-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 LM2670SD-3.3 part is unused and in its original packaging.

Return procedure for LM2670SD-3.3:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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