LM2596SX-ADJ/NOPB-Q1 - 3A 150kHz Buck Regulator | TI
MPN: LM2596SX-ADJ/NOPB-Q1 β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.1 | $2.10 |
| 10 | $1.89 | $18.90 |
| 100 | $1.55 | $155.00 |
| 500 | $1.25 | $625.00 |
| 1,000 | $1.02 | $1,020.00 |
Drop-in alternatives for LM2596SX-ADJ/NOPB-Q1 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:
LM2596SX-ADJ/NOPB
β Drop-Inβ In Stock
$1.82 / Unit
View Datasheet βLM2596SX-12/NOPB
β Drop-Inπ Reference alternative (not in catalog)
LM2596S-ADJ/NOPB
β Drop-Inπ Reference alternative (not in catalog)
XL2596-ADJ
β Drop-Inπ Reference alternative (not in catalog)
LM2596SX-ADJ/NOPB-Q1 Maximum Ratings & Electrical Characteristics
| Topology | Step-Down (Buck) Switching Regulator |
| Output Type | Adjustable |
| Output Voltage Range | 1.23 V to 37 V |
| Input Voltage Range | 4.5 V to 40 V |
| Maximum Output Current | 3 A |
| Switching Frequency | 150 kHz (fixed) |
| Quiescent Current | [DATA_NEEDED: quiescent current] |
| Efficiency | [DATA_NEEDED: typical efficiency] |
| Reference Voltage | 1.23 V |
| Operating Temperature | -40C to +125C (TJ) |
| Package | TO-263-6, D2PAK (5 Leads + Tab), KTT |
| Mounting Type | Surface Mount |
| Protection Features | Current limit, thermal shutdown |
| Number of Outputs | 1 |
| Polarity | Positive |
| RoHS Status | Compliant (NOPB) |
LM2596SX-ADJ/NOPB-Q1 Pin Configuration
| Pin 1 | VIN β Positive input supply, 4.5V to 40V |
| Pin 2 | Output (Switch) β Switching node to inductor and catch diode |
| Pin 3 | Ground β Ground (also exposed tab) |
| Pin 4 | Feedback (ADJ) β Feedback input, 1.23V reference; tie to divider for adjustable output |
| Pin 5 | ON/OFF β TTL-compatible shutdown; ground or low for normal operation |
| Pin Tab | Ground (Tab) β Exposed tab connected to ground for thermal dissipation |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
LM2596SX-ADJ/NOPB-Q1 is suitable for 6 applications: Automotive Auxiliary Power Rails, Industrial 24V Bus Point-of-Load Conversion, Microcontroller and Logic Board Supplies, Battery-Powered and Portable Equipment, LED Lighting Drivers and Fixture Power, Test Benches, Hobby, and Prototyping Supplies.
Automotive Auxiliary Power Rails
The LM2596 converts 12V/24V automotive battery rails to 5V or 3.3V for ECUs, infotainment, and sensor clusters. Its 40V input ceiling provides margin for load-dump and cranking transients, and the -Q1 grade supports automotive quality flows. Placed upstream of LDOs for noise-sensitive loads, it delivers bulk current at up to 3A with high efficiency, reducing heat in sealed enclosures. The fixed 150 kHz switching frequency keeps EMI out of the AM band when using spread filtering and short input loops. A Schottky catch diode and low-ESR output capacitor complete a four-component external BOM.
Recommended
Industrial 24V Bus Point-of-Load Conversion
Industrial PLCs, motor drives, and instrumentation commonly distribute 24V, which the LM2596 steps down to 5V or 12V auxiliary rails. The wide 4.5V-40V input tolerates bus sag and surges, while cycle-by-cycle current limiting protects against shorts in long field wiring. At 3A output it powers relays, displays, and microcontroller boards directly. The TO-263 tab soldered to a ground pour dissipates switching losses without a heatsink at moderate loads, and the adjustable version lets one design cover multiple rail voltages by changing only the feedback divider resistors.
Recommended
Microcontroller and Logic Board Supplies
Buck-derived 5V or 3.3V rails feed MCUs such as the TMS320F2800x and MSPM0 families. The LM2596's 150 kHz operation and low external component count make it a forgiving first switching design, and its 1.23V reference supports outputs down to logic levels. Output ripple of a few tens of millivolts with a 220 uF low-ESR capacitor is acceptable for digital loads, while analog sections should add an LDO post-regulator. The enable-free, fixed-frequency behavior simplifies power sequencing relative to controllers requiring external compensation design.
Recommended
Battery-Powered and Portable Equipment
For 12V lead-acid or multi-cell lithium packs, the LM2596 regulates down to system rails with efficiency that extends battery runtime versus linear solutions. Its low component count suits hand-built and serviceable equipment, and thermal shutdown plus current limit protect against abuse. The 5 mA quiescent-class overhead means it is best for devices drawing hundreds of milliamps to amps, not ultra-low-power sleep designs - newer parts like the TPS62840 suit nanoamp standby. Output regulation remains stable across the discharge curve thanks to the wide input range.
Recommended
LED Lighting Drivers and Fixture Power
The LM2596 regulates constant-voltage buses feeding LED strings through current-limiting circuitry in signage, architectural, and task lighting. Its 40V input handles 24V fixture supplies with margin, and 3A output supports multi-watt LED loads. Efficiency around 90% keeps fixture enclosures cool, extending LED and driver lifetime. Fixed-frequency operation avoids visible flicker and audible noise when paired with adequate output capacitance. For precise current regulation, pair the LM2596 voltage rail with a dedicated LED driver such as the LP8860-Q1 for dimming and fault diagnostics.
Recommended
Test Benches, Hobby, and Prototyping Supplies
Because it needs only four external components, the LM2596 is the classic choice for DIY bench supplies, module boards, and prototype power stages. The adjustable version spans 1.23V-37V from a single design, and the TO-263 package is hand-solderable on adapter boards. Current limit and thermal shutdown make it forgiving of beginner wiring errors. Designers should still follow datasheet layout rules - short input capacitor loops and a solid ground - to avoid instability. When moving to production, the same schematic can be migrated to higher-efficiency TI bucks if size or efficiency demands it.
Recommended
Recommended Products Summary
Engineering reference data for LM2596SX-ADJ/NOPB-Q1 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LM2596SX-ADJ/NOPB | LM2596SX-12/NOPB | LM2596S-ADJ/NOPB | XL2596-ADJ | TPS5450QDDARQ1 |
|---|---|---|---|---|---|---|
| Package | TO-263-5 (D2PAK, KTT) | TO-263-5 - same | TO-263-5 - same | TO-263-5 - same | TO-263-5 - same | SO-8 (DDA) - different |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | XLSEMI | Texas Instruments |
| Output Current | 3 A | 3 A | 3 A | 3 A | 3 A | 5 A |
| Input Voltage Range | 4.5 V to 40 V | 4.5 V to 40 V | 4.5 V to 40 V | 4.5 V to 40 V | [DATA_NEEDED] | [DATA_NEEDED] |
| Output Voltage | Adjustable 1.23 V to 37 V | Adjustable 1.23 V to 37 V | Fixed 12 V | Adjustable 1.23 V to 37 V | Adjustable | Adjustable 0.8 V+ |
| Switching Frequency | 150 kHz | 150 kHz | 150 kHz | 150 kHz | 180 kHz | 500 kHz |
| Automotive Grade (Q1) | Yes (per -Q1 suffix; verify ordering PN) | No (standard grade) | No (standard grade) | No (standard grade) | No | Yes (AEC-Q100) |
| Output Type | Adjustable | Adjustable | Fixed | Adjustable | Adjustable | Adjustable |
Key Differentiators
- Only four external components required (vs TPS5450QDDARQ1)
- Wider 40V input headroom in a 3A part (vs XL2596-ADJ)
- Adjustable output covers 1.23V-37V from one design (vs LM2596SX-12/NOPB)
Design Notes
Keep the loop from VIN capacitor, the internal power switch, catch diode, and inductor as short and wide as possible - this high-di/dt loop dominates radiated EMI at 150 kHz harmonics. Solder the TO-263 exposed tab to at least 1 square inch of ground copper; the tab is the primary heat-removal path and the IC ground reference. Place the feedback divider close to the ADJ pin and route the sense trace away from the switch node and inductor to prevent offset errors.
Use a Schottky catch diode rated at least 1.2x the maximum input voltage and the full peak switch current (e.g., 40V-60V, 3A class such as SR340/SS34 types). The diode reverse recovery and forward drop directly set efficiency; standard silicon diodes cause significant losses and possible thermal runaway. Input capacitor should be a low-ESR electrolytic or ceramic combination sized for the RMS ripple current per TI datasheet LM2596 Figure tables.
The ON/OFF pin (pin 5) must be grounded or pulled low for normal operation - a floating pin can shut the regulator down. Do not exceed 40V input including transients. Note that verified distributor listings confirm the standard LM2596SX-ADJ/NOPB; if your BOM requires AEC-Q100 qualification, confirm the exact -Q1 ordering part number with TI before release, as ordering suffixes differ.
Compliance Information
NOPB suffix indicates lead-free/RoHS-compliant plating. -Q1 suffix denotes AEC-Q100 automotive qualification per TI naming; exact qualification level should be confirmed on TI.com product page.
