LM2596T-12 - 3A 12V Buck Regulator 150kHz | Texas Instruments
MPN: LM2596T-12 β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.05 | $3.05 |
| 10 | $2.74 | $27.40 |
| 100 | $2.35 | $235.00 |
| 500 | $2.01 | $1,005.00 |
| 1,000 | $1.68 | $1,680.00 |
LM2596T-12 Overview
A buck regulator is a type of switching DC-DC converter that steps a higher input voltage down to a lower output voltage using an internal power switch, an inductor, and a diode. Within the power management hierarchy, the LM2596T-12 belongs to the switching regulator family, sitting above linear regulators in efficiency and below power modules in integration. Switching regulators dissipate far less power than LDOs because the pass element switches rather than conducts continuously.
Key features include a fixed 12 V output with plus/minus 4 percent maximum tolerance over line and load, a 3 A output load current capability, a low external component count requiring only a few passives, and a 150 kHz internal oscillator that permits smaller inductors than 52 kHz predecessors such as the LM2576. An ON/OFF pin enables low-current shutdown, and the family also offers 3.3 V, 5 V, and adjustable (1.2 V to 37 V) versions in the same footprint.
Technically, the LM2596 is a monolithic bipolar IC integrating the reference, error amplifier, oscillator, and 3 A NPN switch. Its non-synchronous buck topology requires an external catch diode and inductor, achieving typical efficiencies of 80 to 92 percent depending on input and load conditions.
Typical applications include industrial 24 V to 12 V rail conversion, automotive accessory power supplies, distributed 12 V logic and relay supplies, and bench or hobby power modules where a rugged through-hole part simplifies assembly.
Design consideration: use the inductor values and diode recommendations from the manufacturer datasheet; the external Schottky diode must be rated for the peak switch current to prevent failure at full load.
This page synthesizes distributor pricing, verified drop-in alternatives, pinout data, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for LM2596T-12 β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
LM2596T-12/NOPB
β Drop-Inπ Reference alternative (not in catalog)
LM2596HVT-12
β Drop-Inπ Reference alternative (not in catalog)
LM2576T-12/NOPB
β Drop-Inπ Reference alternative (not in catalog)
LM2596T-ADJ
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
LM2596T-12
β Drop-Inβ In Stock
$1.68 / Unit
View Datasheet βXL2596-12
β Drop-Inπ Reference alternative (not in catalog)
LM2596T-12 Maximum Ratings & Electrical Characteristics
| Topology | Step-Down (Buck) Switching Regulator |
| Output Type | Fixed Positive |
| Output Voltage | 12 V |
| Output Voltage Tolerance | Β±4% max over line and load |
| Maximum Output Current | 3 A |
| Input Voltage Range | 4.5 V to 40 V |
| Switching Frequency | 150 kHz |
| Adjustable Output Version Range | 1.2 V to 37 V (family) |
| Shutdown Feature | ON/OFF pin |
| Number of Outputs | 1 |
| Mounting Type | Through Hole |
| Package | TO-220-5 (Formed Leads) |
| Family Output Versions | 3.3 V, 5 V, 12 V, Adjustable |
| Technology | Bipolar monolithic, SIMPLE SWITCHER |
| RoHS Status | unknown (see LM2596T-12/NOPB for lead-free variant) |
LM2596T-12 Pin Configuration
| Pin 1 | +Vin β Unregulated input supply voltage, 4.5 V to 40 V |
| Pin 2 | Output β Internal switch output; connect to inductor and catch diode |
| Pin 3 | Ground β Ground (also the TO-220 tab connection path) |
| Pin 4 | Feedback β Feedback sense; tied to output on fixed 12 V version |
| Pin 5 | ON/OFF β Shutdown control; pull low or leave low-side to enable regulator |
Typical Applications
LM2596T-12 is suitable for 6 applications: Industrial 24 V to 12 V Rail Conversion, Automotive Accessory Power Supply, Distributed 12 V Logic and Relay Supplies, Bench and Hobby DC-DC Power Modules, Solar and Battery-Powered Equipment, Networking and Communication Equipment Auxiliary Power.
Industrial 24 V to 12 V Rail Conversion
Industrial control panels commonly distribute a 24 V bus that must be stepped down to 12 V for relays, indicators, sensors, and auxiliary logic. The LM2596T-12 fits this role directly: its 4.5 V to 40 V input range accommodates the 24 V nominal bus plus headroom to 40 V for surge conditions, while the fixed 12 V output with plus/minus 4 percent tolerance meets most relay and sensor supply requirements. The 3 A rating covers typical actuator and communication loads. Placed with a datasheet-recommended inductor and a 3 A Schottky catch diode, it achieves roughly 85 to 90 percent efficiency at mid loads, keeping dissipation in the 2 to 4 W range where the TO-220 tab on a small heatsink suffices. Unlike a linear regulator, which would burn the full 12 V drop as heat, the switching topology cuts thermal design effort dramatically.
Recommended
Automotive Accessory Power Supply
Automotive 12 V accessory rails fluctuate widely with cold crank and load dump events, so a regulator with generous input headroom is essential. The LM2596T-12 accepts up to 40 V continuous input, covering most 12 V to 14 V automotive conditions when paired with input transient protection, and its 3 A capability powers dash accessories, cameras, telematics dongles, and lighting modules. The through-hole TO-220 package withstands vibration and is simple to service in the field, a reason the part remains popular in aftermarket automotive electronics. In this role the regulator switches at a fixed 150 kHz, keeping ripple components above the audio band and away from AM radio frequencies when input and output filtering follow the TI datasheet recommendations. Designers should add a TVS diode upstream to clamp load-dump spikes beyond the 40 V absolute limit.
Recommended
Distributed 12 V Logic and Relay Supplies
Larger machines and building systems often carry a higher distribution voltage and generate local 12 V at each module. The LM2596T-12 serves as a compact point-of-load converter for these distributed architectures: each board places one TO-220 regulator, an input capacitor, an output capacitor, an inductor, and a Schottky diode to create a local 12 V, 3 A-capable rail. The fixed-voltage version requires no feedback divider, reducing BOM count and assembly errors; the ON/OFF pin allows a microcontroller to sequence or shut down the rail with a logic signal. Because the whole LM2596 family shares the same 5-pin footprint, the same PCB can carry the 3.3 V, 5 V, 12 V, or adjustable versions to serve multiple rail voltages from one layout, simplifying procurement and board reuse across product variants.
Recommended
Bench and Hobby DC-DC Power Modules
The LM2596T-12 is a fixture in DIY and educational power modules because the through-hole TO-220 package is easy to solder, probe, and replace, and the tiny external component count yields a working buck converter in minutes. Countless buck converter modules built around the LM2596 family provide fixed or adjustable outputs up to 3 A for robotics, Arduino projects, LED drivers, and radio equipment. The fixed 12 V version suits direct 12 V loads such as fans, routers, LED strips, and motors from a 19 V to 24 V laptop adapter input. Its 150 kHz switching frequency keeps the inductor small, typically in the 33 uH to 68 uH range for 12 V output at moderate loads per the datasheet selection tables. Hobbyists should still observe the datasheet diode and capacitor recommendations to avoid instability and overheating at full 3 A load.
Recommended
Solar and Battery-Powered Equipment
Off-grid solar systems with 18 V to 24 V panels and 12 V battery buses benefit from the LM2596T-12's wide 4.5 V to 40 V input window and high efficiency. In battery chargers, monitoring nodes, gateways, and lighting controllers, the regulator converts panel or battery voltage to a clean 12 V rail with 85 to 90 percent typical efficiency, conserving energy compared with linear alternatives. The ON/OFF pin supports firmware-controlled shutdown for ultra-low standby draw in duty-cycled solar equipment, cutting quiescent consumption to the microamp-level shutdown current. Designers must ensure the input stays below 40 V under open-circuit panel conditions; for higher-voltage panels, the 60 V input LM2596HV family member is the pin-compatible upgrade. The rugged TO-220 package also tolerates the wide temperature swings of outdoor enclosures when thermally bonded to an aluminum chassis.
Recommended
Networking and Communication Equipment Auxiliary Power
Routers, switches, and industrial communication nodes frequently need a local 12 V rail derived from a 24 V or 36 V backplane input. The LM2596T-12 supplies this auxiliary rail at up to 3 A, enough for the main board electronics, and its fixed-frequency 150 kHz operation places switching artifacts predictably above the communication-relevant bands, simplifying EMI filtering to CISPR-style conducted-emission targets when the datasheet input filter values are followed. The plus/minus 4 percent output accuracy over line and load is adequate for relays, optical modules, and secondary DC-DC stages that further regulate to 3.3 V or 1.8 V. Because the part is available from multiple second sources in the identical TO-220-5 footprint, procurement teams can dual-source the rail without layout changes, improving long-term supply resilience for long-lifecycle industrial communication hardware.
Recommended
Recommended Products Summary
Engineering reference data for LM2596T-12 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LM2596T-12/NOPB | LM2596HVT-12 | LM2576T-12/NOPB | HTC LM2596T-12 | XL2596-12 |
|---|---|---|---|---|---|---|
| Package | TO-220-5 (formed leads) | TO-220-5 - same | TO-220-5 - same | TO-220-5 - same | TO-220-5 - same | TO-220-5 - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | HTC Korea | XLSEMI |
| Output Voltage | 12 V fixed | 12 V fixed | 12 V fixed | 12 V fixed | 12 V fixed | 12 V fixed |
| Inductor Requirement | Per TI 150 kHz selection table | Identical to this product | Identical to this product | Larger values per 52 kHz table | Verify against TI table | Verify against vendor table |
Key Differentiators
- 150 kHz operation shrinks magnetics (vs LM2576T-12/NOPB)
- Standard 40 V input rating for mainstream buses (vs LM2596HVT-12)
- Authentic TI supply chain with lead-free option (vs HTC LM2596T-12)
Design Notes
Select the catch diode for peak, not average, current. The switch node swings between Vin and roughly -0.5 V, so the Schottky diode (e.g., 1N5822 class, 3 A/40 V) conducts the full inductor current during the off-time. At 3 A load and 40 V input the diode dissipation can reach 2 to 3 W, so a TO-220 packaged Schottky with copper area is preferable to an SMA part at high load. Use the TI LM2596 datasheet inductor coding tables: for 12 V output from about 24 V input at 3 A, expect roughly 33 uH; under-inductance causes subharmonic ripple and possible current limit trips.
Estimated: at Vin = 24 V, Vout = 12 V, and 2 A load with about 88 percent efficiency, input power is roughly 27.3 W and loss about 3.3 W. The TO-220 junction-to-ambient thermal resistance without heatsink is high, so bond the tab to a heatsink or a 1+ square inch PCB/copper plane. Keep junction temperature well below the maximum rating for long-term reliability; the tab is at ground potential, allowing direct chassis mounting without isolation hardware.
Keep the loop from the Output pin (pin 2) through the catch diode and back to Ground (pin 3) as short and tight as possible; this high-di/dt loop is the dominant EMI source in an LM2596 layout. Place the input capacitor within millimeters of pin 1 to ground, and route the feedback trace (pin 4) away from the inductor and diode to prevent ripple pickup. For through-hole prototypes, twisted or short direct wiring of the power path still gives stable results, but hand-wired long leads invite instability at light load.
The ON/OFF pin (pin 5) is active-low enable: the regulator is ON when pin 5 is grounded and OFF when pulled above approximately 1.3 V. A floating pin 5 is a frequent cause of 'my converter does not start' failures - tie it to ground if shutdown is not used. Also verify genuine sourcing: TO-220 parts marked LM2596 from low-cost marketplaces are frequently cloned with derated 40 V tolerance and higher ripple; for certified products order from franchised distributors with the TI/NOPB suffix.
Compliance Information
Verified web data does not state compliance status for the bare LM2596T-12 ordering code. The TI LM2596T-12/NOPB ordering code designates the RoHS lead-free finish variant of the same device; use NOPB when lead-free compliance is required.
