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Texas Instruments LM2670SX-12
- Part No.:
- LM2670SX-12
- Manufacturer:
- Texas Instruments
- Package:
- TO-263-8, D2PAK (7 Leads + Tab), TO-263CA
- Datasheet:
-
LM2670SX-12.pdf
- Description:
- IC REG BUCK 12V 3A TO263
- Quantity:
- Payment:
- Shipping:
Inventory:3,170
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Product details
Overview
LM2670SX-12 from Texas Instruments is a monolithic 3-A synchronous step-down (buck) DC/DC voltage regulator with fixed 12-V output, 8–40-V input range, 260-kHz internal oscillator, ±2% output tolerance, and 150-mΩ DMOS high-side switch - used in battery chargers, communications power supplies, and industrial preregulators.
For engineers reviewing the LM2670SX-12 datasheet, LM2670SX-12 pinout, LM2670SX-12 application, or LM2670SX-12 equivalent, key selection criteria include its 94% peak efficiency at 24-VIN/5-A, 50-µA shutdown current, SYNC capability for ripple frequency control, and TO-263-7 thermal performance with 26°C/W RθJA under optimized PCB layout.
Technical Context
The LM2670SX-12 implements a voltage-mode PWM controller with an integrated 150-mΩ DMOS high-side switch and bootstrap gate drive (CBOOST required). It operates in continuous conduction mode with fixed 260-kHz switching frequency or external synchronization from 280–400 kHz.
Its feedback loop uses an internal resistive divider for 12-V regulation, eliminating external resistor networks. Protection features include thermal shutdown, cycle-by-cycle current limiting (3.6–5.4 A), and ON/OFF-controlled shutdown with 50-µA standby current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output voltage | Fixed 12 V ±2% over –40°C to 125°C junction temperature and full line/load conditions - ensures stable rail for downstream logic or analog circuitry without trimming. |
| Input voltage range | 8 V to 40 V - supports wide industrial and automotive battery-derived inputs, including 12-V, 24-V, and 36-V nominal systems. |
| Max output current | 3 A continuous - delivers regulated 12-V power to moderate-power loads such as FPGAs, RF modules, or motor drivers. |
| Peak efficiency | 94% at VIN = 24 V, IOUT = 5 A - minimizes thermal stress and enables compact thermal design in enclosed environments. |
| Switch ON-resistance | 0.15 Ω typical - reduces conduction loss and improves light-load efficiency versus higher-RDS(ON) alternatives. |
| Standby current | 50 µA when ON/OFF pin < 0.8 V - enables ultra-low-power system sleep states without auxiliary LDOs. |
| Oscillator frequency | 260 kHz fixed (225–280 kHz over temp) - balances EMI, inductor size, and capacitor ripple requirements for cost-sensitive designs. |
Pinout & Package
LM2670SX-12 is packaged in TO-263-7 (KTW), a thermally enhanced surface-mount package with 10.10 mm × 8.89 mm body size and exposed thermal pad for PCB heat sinking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (SW) | Switch output | Drain node of internal high-side DMOS FET - connects directly to inductor and Schottky diode cathode; switches between VIN and ~–0.5 V during operation. |
| 2 (VIN) | Input supply | Main power input (8–40 V); supplies both load path and internal bias - requires low-ESR ceramic capacitor placed within 5 mm of pin. |
| 3 (CBOOST) | Bootstrap capacitor | Connects to SW via 100-nF ceramic capacitor - provides gate drive voltage > VIN to fully enhance internal FET and minimize RDS(ON). |
| 4 (GND) | Power ground | Primary return path for VIN, SW, and internal circuits - must tie to large copper pour and connect to CIN/COUT ground terminals with minimal trace length. |
| 5 (SYNC) | Frequency sync input | Accepts external TTL/CMOS clock (280–400 kHz) to lock switching frequency - enables consistent EMI filtering and avoids beat frequencies in multi-rail systems. |
| 6 (FB) | Feedback input | Internally tied to 12-V divider - connect directly to output capacitor for fixed 12-V regulation; no external resistors needed. |
| 7 (ON/OFF) | Enable control | Active-high logic input (1.4 V threshold); float or pull ≥2 V to enable, ≤0.8 V to enter 50-µA shutdown - supports microcontroller-based power sequencing. |
Key Features
| Feature | Design Value |
|---|---|
| Synchronous buck topology | Eliminates external catch diode - reduces conduction loss, improves efficiency by ~3–5% vs. asynchronous equivalents at 3-A load. |
| Integrated 150-mΩ DMOS switch | Enables single-chip 3-A solution without external MOSFETs - simplifies BOM and layout while maintaining thermal headroom in TO-263. |
| ±2% output voltage accuracy | Guaranteed over full temperature and line/load range - removes need for post-regulation trimming in precision 12-V applications like data acquisition front-ends. |
| External SYNC capability | Allows precise ripple frequency positioning - critical for meeting CISPR-22 conducted EMI limits in telecom and radio equipment. |
| Thermal shutdown + current limit | Protects against sustained overload or ambient overheating - latches off until reset by cycling ON/OFF or VIN, preventing catastrophic failure. |
Applications
| Battery Charger Power Stage | Communications Equipment Preregulator |
|---|---|
Use Scenario: Step-down conversion from 24-V or 36-V battery stack to regulated 12-V rail feeding charge management ICs and sensing circuitry. IC Role / Device Role / Timing Role: Primary DC/DC converter providing isolated, efficient, and thermally robust 12-V supply with fast transient response to charging current changes. Use Value: 94% efficiency at 24-VIN/3-A reduces heat buildup in sealed battery enclosures; 50-µA shutdown extends standby time during idle cycles. |
Use Scenario: Pre-regulating unfiltered 24-V telecom bus to clean 12-V supply for RF transceivers, baseband processors, and clock distribution ICs. IC Role / Device Role / Timing Role: High-efficiency buck converter synchronized to system clock to fix ripple frequency and avoid interference with sensitive receive bands. Use Value: SYNC pin enables deterministic 300-kHz ripple placement - simplifies EMI filter design and eliminates variable-frequency noise coupling into adjacent RF sections. |
| Industrial PLC I/O Module Supply | Automotive Diagnostic Tool Power |
Use Scenario: Generating 12-V from wide-range 9–36-V vehicle or factory bus to power isolated digital I/O, ADC references, and optocoupler drivers. IC Role / Device Role / Timing Role: Robust main regulator handling input transients (load dump, cold crank) while maintaining tight 12-V regulation for analog signal integrity. Use Value: 8–40-V input range survives 35-V load dump pulses; ±2% tolerance ensures accurate 12-V reference for 16-bit ADCs and precision op-amps. |
Use Scenario: Portable OBD-II diagnostic tool powered from 12-V vehicle battery, requiring reliable 12-V rail despite cranking dips below 6 V. IC Role / Device Role / Timing Role: Primary buck regulator with ON/OFF control enabling MCU-driven power gating and low-quiescent sleep modes. Use Value: 50-µA shutdown current extends battery life during intermittent use; thermal shutdown prevents damage during extended cranking 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 |
|---|---|---|---|
| LM2671MX-12 | Same architecture but rated for 2.5-A max output; lower current limit (3.2–4.2 A) and higher RDS(ON) (0.18 Ω). | Suitable for lighter 12-V loads (<2.5 A) where thermal margin is less constrained and cost reduction is prioritized. | Select LM2671MX-12 only if load current remains ≤2.5 A continuously and board space allows same TO-263 footprint. |
| TPS54319RTER | 3-A synchronous buck with 4.5–28-V input, adjustable output, 570-kHz switching, and integrated compensation - no external SYNC or CBOOST required. | Better suited for designs needing programmable output or higher switching frequency to shrink magnetics, but lacks 40-V input rating. | Choose TPS54319RTER when input stays ≤28 V and design flexibility (adjustable VOUT, smaller inductors) outweighs need for 40-V tolerance and SYNC control. |
Compared with LM2671MX-12, the LM2670SX-12 delivers higher current and better efficiency at full load; versus TPS54319RTER, it trades adjustable output and higher frequency for wider input range, SYNC capability, and proven ruggedness in 40-V industrial environments.
Availability
LM2670SX-12 is available at Aetrix Electronics and suitable for battery chargers, communications equipment power stages, and industrial PLC I/O modules requiring stable component supply, long-term lifecycle support, and guaranteed 12-V regulation performance.
Supply support for LM2670SX-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, delivering analog and embedded processing solutions across industrial, automotive, and communications markets since 1930.
The LM2670 series belongs to TI's SIMPLE SWITCHER® portfolio - designed specifically for engineers seeking easy-to-use, high-efficiency DC/DC regulators that minimize external component count and eliminate complex compensation design.
FAQ
What is the maximum input voltage rating for the LM2670SX-12?
The LM2670SX-12 has an absolute maximum input voltage rating of 45 V, with recommended operating range from 8 V to 40 V. Operation above 40 V is not advised for long-term reliability, and transient spikes beyond 45 V may cause permanent damage. The device is commonly used with 24-V and 36-V industrial buses where load dump protection is implemented upstream.
Does the LM2670SX-12 require an external diode?
No, the LM2670SX-12 does not require an external diode because it integrates a synchronous rectifier - the internal DMOS switch replaces the traditional catch diode in the buck topology. This eliminates diode forward voltage drop and improves efficiency, especially at higher currents. Only an external inductor and output capacitor are mandatory for basic operation.
Can the LM2670SX-12 be synchronized to an external clock?
Yes, the LM2670SX-12 supports external synchronization via its SYNC pin (Pin 5). An external TTL- or CMOS-compatible clock signal between 280 kHz and 400 kHz can be AC-coupled to this pin to precisely control switching frequency. This feature is used to align ripple frequency for EMI compliance and avoid heterodyning in multi-converter systems.
What is the thermal performance of the LM2670SX-12 in TO-263-7 package?
In the TO-263-7 (KTW) package with proper PCB copper area (≥0.4896 in² of 1-oz copper connected to the thermal pad), the LM2670SX-12 achieves a junction-to-ambient thermal resistance (RθJA) of 35°C/W. With 1.0064 in² copper and 12 vias to inner layers, RθJA drops to 26°C/W - enabling full 3-A operation at up to 85°C ambient without forced airflow.
How is output voltage set on the LM2670SX-12?
The LM2670SX-12 has a factory-trimmed internal resistive divider that fixes the output to 12 V. No external feedback resistors are required - simply connect Pin 6 (FB) directly to the output capacitor's positive terminal. This simplifies layout and eliminates resistor tolerance errors that would affect regulation accuracy in adjustable versions.
LM2670SX-12 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- TO-263-8, D2PAK (7 Leads + Tab), TO-263CA
- 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):
- 12V
- 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:
- TO-263 (DDPAK-7)
LM2670SX-12 FAQ
1.How can I place an order for LM2670SX-12 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2670SX-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 LM2670SX-12 reliable?
The price and inventory of LM2670SX-12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2670SX-12 is usually 5 days.
3.What payment methods are accepted for LM2670SX-12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2670SX-12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2670SX-12?
LM2670SX-12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2670SX-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 LM2670SX-12?
For technical support, including LM2670SX-12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2670SX-12 requirements.
6.How does Aetrix verify that LM2670SX-12 is sourced from the original manufacturer or authorized distributors?
All LM2670SX-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 LM2670SX-12 meets industry standards.
7.What is the process for return or replacement of LM2670SX-12?
All LM2670SX-12 units undergo pre-shipment inspection (PSI). If there is an issue with LM2670SX-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 LM2670SX-12 part is unused and in its original packaging.
Return procedure for LM2670SX-12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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