LM2596S-ADJ/NOPB vs LM2596S-5.0-EV: Component Comparison
Quick verdict
For designs requiring adjustable output voltage from 1.2V up to 37V at 3A, the LM2596S-ADJ/NOPB is the straightforward choice due to its dedicated adjustable feedback input and broad output voltage range. If your design targets a fixed 5V output with tighter line/load regulation and slightly better-controlled switching parameters, the LM2596S-5.0-EV is preferable, especially when working near or above 25V input voltages given its higher voltage rating variants.
Spec comparison table
| Spec | LM2596S-ADJ/NOPB | LM2596S-5.0-EV | Notes |
|---|---|---|---|
| Function | Step-Down Buck | Step-Down Buck | Equivalent topology. |
| Input voltage max | 40 V | 40 V (standard), 57 V (HV version) | LM2596S-5.0-EV offers a 57V HV version option, better for higher input voltage margins. |
| Input voltage min | 4.5 V | Not explicitly specified (UVLO 8–13V) | LM2596S-ADJ/NOPB supports operation down to 4.5V input; LM2596S-5.0-EV has higher undervoltage lockout (8–13V). Lower input voltage operation favors LM2596S-ADJ. |
| Mounting type | Surface Mount | Surface Mount | Identical. |
| Number of outputs | 1 | 1 | Identical. |
| Operating temp range | -40°C to 125°C (TJ) | Not specified | LM2596S-ADJ/NOPB datasheet specifies -40°C to 125°C; LM2596S-5.0-EV lacks explicit TJ range. |
| Output configuration | Positive | Positive | Identical. |
| Output current max | 3 A | 3 A ±4% max | Comparable current capability; LM2596S-5.0-EV guarantees ±4% max variation over line/load. |
| Output type | Adjustable | Fixed 5.0 V (EV suffix) | LM2596S-ADJ/NOPB supports adjustable output from 1.2V to 37V; LM2596S-5.0-EV fixed at 5V. |
| Output voltage max | 37 V | 25 V (max) | LM2596S-ADJ/NOPB supports higher max output voltage (37V vs 25V). |
| Output voltage min | 1.2 V | 1.2 V (adjustable range min noted) | LM2596S-ADJ/NOPB adjustable down to 1.2V; LM2596S-5.0-EV fixed at 5V but datasheet notes adjustability. Unclear if 5.0-EV is adjustable or fixed — nominally fixed 5V. |
| Package case | TO-263-6 (D2PAK, 5 leads + tab) | TO-263-6 (D2PAK, 5 leads + tab) | Identical package. |
| Supplier device package | TO-263 (DDPAK-5) | TO-263-5L | Slight difference in pin numbering; may impact footprint compatibility. |
| Switching frequency typ | 150 kHz | 150 kHz | Identical switching frequency. |
| Synchronous rectifier | No | No | Both lack synchronous rectification. |
| Topology | Buck | Buck | Identical. |
| Oscillator frequency tolerance | Not specified | ±15% max | LM2596S-5.0-EV specifies ±15% oscillator frequency tolerance, potentially impacting noise and ripple design. |
| Standby current typ | Not specified | 80 µA | LM2596S-5.0-EV has a low standby current spec beneficial for low power modes. |
| Feedback bias current | Not specified | 10 nA typ, 50/100 nA max | Low feedback bias current in 5.0-EV supports higher impedance feedback networks, reducing noise and offset. |
| Saturation voltage (switch) | Not specified | Typ 1.16 V, max 1.4–1.5 V | Known saturation voltage helps thermal and efficiency calculation; data missing for ADJ. |
| Diode forward voltage drop | Not specified | 0.5 V | Important for efficiency calculation; data missing for ADJ. |
| Max duty cycle | Not specified | 100% | Allows full input voltage down to output voltage operation; no data for ADJ. |
| Min duty cycle | Not specified | 0 | Same as above. |
| Peak current min | Not specified | 3.4–3.6 A | Peak current rating important for transient loads; only in 5.0-EV datasheet. |
| Peak current typ | Not specified | 4.5 A | |
| Peak current max | Not specified | 6.9–7.5 A | |
| Output leakage current max | Not specified | 50 µA | Important for shutdown or standby behavior; only 5.0-EV documented. |
| Output leakage current typ | Not specified | 2 mA | |
| Quiescent current typ | Not specified | 5 mA | Quiescent current critical for battery-powered or low power applications. |
| Quiescent current max | Not specified | 10 mA | |
| Thermal resistance TO-263 to case | Not specified | 20–50 °C/W | Wide range, but 5.0-EV datasheet provides thermal resistance data; ADJ lacks. |
| On/off pin logic input | Not specified | 1.3 V | Required for enable pin interface design; only 5.0-EV documented. |
| Undervoltage lockout voltage min | Not specified | 8 V | ADJ supports as low as 4.5 V input; 5.0-EV has UVLO of 8–13 V, limiting low-voltage operation. |
| Undervoltage lockout voltage max | Not specified | 13 V | |
| Input filter capacitor min | Not specified | 68 µF/25 V | 5.0-EV datasheet recommends large input capacitance, potentially increasing BOM cost and size. |
| Input filter capacitor typ | Not specified | 470 µF/50 V | |
| Inductor value typ | Not specified | 33 µH | ADJ recommends 68 µH, 5.0-EV 33 µH, affecting transient and ripple performance. |
| Startup time min | Not specified | 2 ms | Startup time affects system power sequencing; only 5.0-EV documented. |
Design trade-offs
The LM2596S-ADJ/NOPB and LM2596S-5.0-EV share the same fundamental buck topology and package style, but their intended use cases diverge primarily around output voltage flexibility and input voltage handling. The adjustable variant (ADJ/NOPB) supports a wide output voltage range from 1.2V to 37V, enabling it to serve a broad set of applications where custom voltages are required. This flexibility comes at the cost of additional external components (feedback resistors) and potentially more sensitive layout requirements due to the adjustable feedback node.
Conversely, the 5.0-EV is nominally a fixed 5V output regulator, with datasheet parameters suggesting it may support some adjustability but primarily optimized for fixed output. Its higher voltage rating option (up to 57V) and well-defined oscillator frequency tolerance (±15%) make it more robust in industrial or automotive environments with wide input voltage swings. The 5.0-EV also documents detailed quiescent currents, standby currents, and UVLO thresholds, aiding low-power and system-level integration, which are absent or unspecified in the ADJ/NOPB datasheet.
Thermal considerations favor the 5.0-EV slightly, as it provides thermal resistance data (20–50 °C/W TO-263), allowing for more accurate thermal management. The ADJ/NOPB lacks this data, requiring conservative assumptions or empirical testing. The switch saturation voltage and diode forward voltage are only available for 5.0-EV, which is critical for accurate efficiency and power loss calculations. Designers may find the 5.0-EV easier to model and simulate.
On the other hand, the ADJ/NOPB variant supports an input voltage minimum of 4.5V compared to the 5.0-EV’s undervoltage lockout range of 8–13V, making the ADJ/NOPB better suited for low-voltage input rails or battery-powered systems that can dip below 8V.
Regarding layout, both parts use the same TO-263