LM2596S-ADJ/NOPB vs LM2596S-ADJ-EV Component Comparison
Quick verdict
For standard 3A buck regulator applications with a straightforward BOM and well-documented TI support, the LM2596S-ADJ/NOPB is the better choice due to its established datasheet and clear packaging details. The LM2596S-ADJ-EV, seemingly an evaluation or alternate source version with minimal spec differences, is appropriate mainly for quick prototyping or when availability or cost from EVVO is preferable, but it lacks detailed documentation and qualification info.
Spec comparison table
| Spec | LM2596S-ADJ/NOPB | LM2596S-ADJ-EV | Notes |
|---|---|---|---|
| Function | Step-Down Buck | Step-Down Buck | Identical functionality, no difference. |
| Input Voltage Max (V) | 40 V | 40 V | Identical max input voltage; no advantage. |
| Input Voltage Min (V) | 4.5 V | Not specified | Known 4.5V min on NOPB is safer for low-voltage designs; EV version unspecified, a risk. |
| Mounting Type | Surface Mount | Surface Mount | Identical; no difference. |
| Number of Outputs | 1 | 1 | Identical. |
| Operating Temperature (TJ) | -40°C to 125°C | -40°C to 125°C | Identical industrial temperature range. |
| Output Configuration | Positive | Positive | Identical. |
| Output Current Max (A) | 3 A | 3 A | Identical max output current. |
| Output Type | Adjustable | Adjustable | Identical. |
| Output Voltage Max (V) | 37 V | 37 V | Identical max output voltage. |
| Output Voltage Min (V) | 1.2 V | 1.2 V | Identical min output voltage. |
| Package Case | TO-263-6, D2PAK (5 Leads + Tab) | TO-263-6, D2PAK (5 Leads + Tab) | Both TO-263 packages, but supplier package names differ slightly (TO-263 (DDPAK-5) vs TO-263-5L). |
| Supplier Device Package | TO-263 (DDPAK-5) | TO-263-5L | Minor naming difference; verify pinout for compatibility (see section on drop-in compatibility). |
| Switching Frequency Typ. (kHz) | 150 kHz | 150 kHz | Identical switching frequency. |
| Synchronous Rectifier | No | No | Both use diode rectification; no difference. |
| Topology | Buck | Buck | Identical. |
| Grade | Not specified | Not specified | No data on grade or qualification for either; unknown quality or reliability differences. |
| Qualification | Not specified | Not specified | No qualification info to distinguish. |
Design trade-offs
From the raw specs, both devices are functionally equivalent step-down regulators with a 3A output current limit, adjustable output voltage from 1.2V to 37V, and a 150kHz switching frequency. The switching frequency is fixed, which simplifies filter design but limits options for EMI optimization or size reduction via higher frequency inductors.
The main practical difference lies in the packaging and sourcing. The LM2596S-ADJ/NOPB is a Texas Instruments branded part with a clear, well-documented datasheet specifying a TO-263-6 (DDPAK-5) package with 5 leads plus a tab. This package is common, with well-known thermal characteristics and footprint references. The LM2596S-ADJ-EV, supplied by EVVO, uses a TO-263-5L package designation, which may indicate subtle mechanical differences or pin configuration changes. This could affect PCB footprint compatibility, thermal pad design, and soldering profiles.
Thermal considerations are critical at 3A output currents. Both parts dissipate significant power depending on input-output voltage differential and efficiency. The TO-263 package (D2PAK) provides a tab for heat sinking, but the exact tab size and thermal resistance could vary slightly between suppliers. Without explicit thermal resistance data, design margins should be conservative, especially for the EVVO part, where qualification and thermal specs are not detailed.
Efficiency curves are not provided for either, but given identical switching frequency, topology, and output current ratings, efficiency differences will mostly depend on process variations and discrete component selection (inductor, diode). Both parts lack synchronous rectification, which means diode conduction losses dominate at higher currents; expect roughly 75–85% efficiency depending on load and input voltage.
Gate drive requirements and layout sensitivity will be similar, as both are monolithic regulators using the same fundamental topology. The 150kHz switch frequency is low enough to reduce layout-induced ringing and EMI compared to higher-frequency regulators but still requires careful input/output decoupling and short high-current loop paths.
Cost at volume will depend on supplier agreements and sourcing. The TI part may command a premium for brand, documentation, and supply chain reliability. The EVVO version might be more cost-effective for low-volume or prototyping, but the lack of detailed datasheet and qualification data introduces risk for production designs.
Use-case fit
Choose LM2596S-ADJ/NOPB when…
- You require a proven, well-documented regulator with clear datasheet support from a major supplier (TI).
- Your design needs guaranteed input voltage operation down to 4.5V, critical for battery-powered or low-voltage input rails.
- Thermal management must be predictable; you rely on established TO-263-6 package thermal specs.
- You are designing for long-term production and require supplier qualification and traceability.
- Your PCB layout references existing TI application notes or reference designs using this exact package and pinout.
Choose LM2596S-ADJ-EV when…
- You are rapidly prototyping and want a potentially lower-cost or locally available alternative.
- Package mechanical differences are acceptable or can be verified against your PCB footprint.
- Input voltage minimum is flexible or can be tested in your target application.
- You are not dependent on detailed TI datasheet support or qualification for your design cycle.
- You require a drop-in replacement for an existing EVVO-based design or sample board.
Drop-in compatibility
Based on the source data, both parts use a TO-263 package with 5 leads plus tab, but the supplier device package is listed as TO-263 (DDPAK-5) for the TI part and TO-263-5L for the EVVO part. This suggests a high likelihood of pin and footprint compatibility, but the slight difference in package naming means the mechanical dimensions and pin spacing should be confirmed before substitution.
Pinouts are not explicitly detailed here, so an engineer must cross-reference datasheets or request mechanical drawings to confirm exact compatibility. Without this, assuming drop-in substitution is risky, especially for production hardware. Electrical characteristics are the same, so if the package and footprint match, the substitution should be straightforward.
Alternatives to consider
- LM2675-ADJ (TI): A lower current (1A) buck regulator with simpler external components, suitable for designs with lower power requirements.
- MP1584EN (Monolithic Power Systems): A 3A adjustable buck converter with integrated synchronous rectification, offering higher efficiency at similar currents.
- TPS5430 (TI): A 3A buck converter with integrated synchronous rectification and adjustable output, providing better efficiency and thermal performance at the cost of a more complex design.