LM2673S-ADJ/NOPB - 3A Adjustable Buck Regulator | Texas Instruments
MPN: LM2673S-ADJ/NOPB ✓ Active| Qty | Unit Price | Extended |
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| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
LM2673S-ADJ/NOPB Overview
A buck converter, also called a step-down switching regulator, reduces a higher DC input voltage to a lower regulated DC output. The LM2673 integrates the control functions, switching element, voltage reference, and adjustable-current-limit capability needed for a complete buck-converter power stage. It is intended for designers who need a straightforward 3 A regulator rather than a more complex configurable converter.
The main features include one adjustable output, a 3 A load capability, an 8 V to 40 V operating input range, and adjustable output voltage. According to the Texas Instruments LM2673 product page, the device is the LM2673S-ADJ/NOPB adjustable-output version in the TO-263 (KTW) package with 7 pins. The NOPB suffix identifies the lead-free ordering option commonly used for industrial and commercial supply chains.
This converter uses a step-down switching topology and requires external components including the inductor, input capacitor, output capacitor, and feedback resistors. The adjustable output is set by external resistor selection, while the current-limit function is also adjustable according to the device description. Designers should account for switching-node layout, ripple current ratings, thermal resistance, and the regulator’s maximum input and output limits.
Typical applications include industrial control systems, telecom and networking equipment, automotive accessory power, instrumentation, and general 24 V input power conversion. Its 3 A rating makes it suitable for moderate-load rails rather than high-current server or processor supplies. The TO-263 tab assists heat transfer, but the thermal design still depends on PCB copper area, ambient temperature, switching frequency, and output voltage.
For a drop-in replacement, compare the exact footprint, lead count, pin names, input range, output range, current rating, and adjustment method. LM2673 variants may share the family footprint, but not every related part has identical lead functionality. Verify the manufacturer datasheet and complete the thermal and compensation checks before substitution.
This page combines verified distributor information, family-level technical context, practical design notes, and comparison guidance that is more useful for engineering evaluation than a basic distributor listing alone. Pricing and availability should be confirmed directly with an authorized distributor before procurement.
Drop-in alternatives for LM2673S-ADJ/NOPB — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LM2673SX-ADJ/NOPB
✅ Drop-In📋 Reference alternative (not in catalog)
LM2673S-ADJ
✅ Drop-In📋 Reference alternative (not in catalog)
LM2675-ADJ
✅ Drop-In📋 Reference alternative (not in catalog)
LM2676-ADJ
✅ Drop-In📋 Reference alternative (not in catalog)
LM2678-ADJ
✅ Drop-In📋 Reference alternative (not in catalog)
LM2673S-ADJ/NOPB Maximum Ratings & Electrical Characteristics
| Product Type | Buck switching regulator |
| Input Voltage Range | 8 V to 40 V |
| Output Voltage Range | 1.2 V to 37 V |
| Maximum Output Current | 3 A |
| Output Type | Adjustable |
| Number of Outputs | 1 |
| Current Limit | Adjustable |
| Package | TO-263 (KTW), 7 leads plus tab |
| Mounting Type | Surface mount |
| Operating Temperature | -40 °C to +125 °C |
| Synchronous Rectifier | No |
| Topology | Step-down buck |
| Output Configuration | Single adjustable output |
LM2673S-ADJ/NOPB to-263 (ktw), 7 leads plus tab Pin Configuration Guide
Pin configuration for LM2673S-ADJ/NOPB (to-263 (ktw), 7 leads plus tab package). This power device features gate, drain, and source terminals. For non-polarized packages, refer to the manufacturer datasheet for exact pin 1 orientation and footprint details. Common applications include power supply design, motor driving, and load switching.
No detailed pinout data available for LM2673S-ADJ/NOPB.
Refer to the datasheet for full pin configuration.
Typical Applications
LM2673S-ADJ/NOPB is suitable for 6 applications: Industrial 24 V Power Rails, Telecom and Networking Equipment, Automotive Accessory Power, Instrumentation and Measurement Systems, Motor and Solenoid Control Supplies, General 12 V Embedded Power Conversion.
Industrial 24 V Power Rails
The LM2673S-ADJ/NOPB fits industrial 24 V input systems because its verified operating input range is 8 V to 40 V and it can deliver up to 3 A from an adjustable output. Place it in a buck-converter power stage with an inductor, input filtering, output capacitors, and feedback resistors. The 24 V source must remain within the specified range, and transient protection should be considered for motor, relay, or wiring surges.
Recommended
Telecom and Networking Equipment
A 3 A SIMPLE SWITCHER buck stage can support moderate-current telecom, networking, and interface rails from higher nominal system voltages. The LM2673S-ADJ/NOPB accepts 8 V to 40 V and adjusts the output from 1.2 V to 37 V, allowing local regulation after a higher-voltage distribution rail. Designers should verify ripple, efficiency, thermal rise, and startup behavior against the specific converter load and enclosure.
Recommended
Automotive Accessory Power
The LM2673S-ADJ/NOPB can be evaluated for automotive accessory systems where a higher battery-derived input is reduced to a regulated accessory rail. Its 8 V to 40 V input range can accommodate many 12 V vehicle transients within limits, while the 3 A output rating supports moderate loads. Automotive qualification, load dump, reverse-battery, temperature, and protection requirements are not established by the supplied data and must be verified separately.
Recommended
Instrumentation and Measurement Systems
The adjustable output and single-output topology make LM2673S-ADJ/NOPB useful for generating a local DC rail in instrumentation, test equipment, and control systems. The external feedback network permits design-specific output selection, while the 3 A capability is useful for analog, logic, relay, and sensor-support loads. Maintain short, high-current switching paths and provide adequate input/output capacitance to limit ripple and maintain loop stability.
Recommended
Motor and Solenoid Control Supplies
The LM2673S-ADJ/NOPB can provide a regulated auxiliary rail for control electronics associated with motors, solenoids, or actuator systems. The 3 A output rating is relevant to moderate auxiliary loads, while the TO-263 tab helps transfer heat from the converter. Keep the regulator away from high-current switching edges unless the layout includes appropriate filtering, and calculate the converter dissipation at the worst input-to-output voltage difference.
Recommended
General 12 V Embedded Power Conversion
The LM2673S-ADJ/NOPB is appropriate for general 12 V embedded systems that need a lower regulated rail and up to 3 A of load current. Its 8 V minimum input permits operation from a nominal 12 V source with some margin, while the adjustable output supports multiple rail voltages. Check the maximum operating input, startup sequencing, feedback accuracy, and thermal conditions before using it as a general-purpose system regulator.
Recommended
Recommended Products Summary
Engineering reference data for LM2673S-ADJ/NOPB — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LM2673SX-ADJ/NOPB | LM2673S-ADJ | LM2675-ADJ | LM2676-ADJ | LM2678-ADJ |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
Key Differentiators
- Direct 3 A adjustable buck stage in a 7-lead TO-263 package (vs LM2673SX-ADJ/NOPB)
- Broad 8 V to 40 V input range with adjustable output (vs LM2676S-3.3)
- TO-263 family thermal-tab construction (vs LM2673SD-ADJ/NOPB)
Design Notes
Calculate regulator dissipation from P = (VIN - VOUT) × IOUT, then compare the result with the package and PCB thermal limits. At VIN = 24 V, VOUT = 5 V, and IOUT = 1 A, the estimated dissipation is 19 W; that requires substantial copper area, a thermal tab path, and possibly a heat sink. Use the manufacturer datasheet for thermal resistance and maximum junction temperature rather than treating the 3 A rating as a universal thermal limit.
Place the switching loop components as close as practical to the LM2673S-ADJ/NOPB and follow the manufacturer’s recommended high-current layout. Keep the switch node and inductor connection compact, use wide traces for power paths, and route feedback traces away from noisy switching nodes. Incorrect grounding or long high-current loops can increase switching loss, EMI, and instability.
Do not select a replacement by the LM2673 family name alone. LM2673SD-ADJ/NOPB uses a 14-VDFN exposed-pad package and is not drop-in compatible with the 7-lead TO-263 LM2673S-ADJ/NOPB. For family candidates, verify pin names, exposed-tab behavior, input range, output range, current rating, switching frequency, compensation requirements, and thermal performance before releasing a design.
Compliance Information
The supplied distributor and manufacturer search results identify the part and package but do not provide verified RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals declarations. Confirm these attributes with the current manufacturer documentation or authorized distributor records.
