LM2596S-12/NOPB vs LM2596S-5.0-EV: Component Comparison for Hardware Design
Quick verdict
For fixed 12 V output applications requiring up to 3 A from input voltages up to 40 V, the LM2596S-12/NOPB is the straightforward choice due to its dedicated 12 V output and proven thermal handling in TO-263-6. Conversely, for 5 V fixed output designs with a slightly lower max input voltage and marginally better peak current specs, the LM2596S-5.0-EV offers tighter feedback bias current and a slightly more flexible input capacitor recommendation, making it preferable for 5 V rails where component optimization matters.
Spec comparison table
| Spec | LM2596S-12/NOPB | LM2596S-5.0-EV | Notes |
|---|---|---|---|
| Output Voltage | 12 V fixed | 5.0 V fixed | Fixed outputs, application dependent on required rail voltage |
| Maximum Output Current | 3 A | 3 A | Equal, both rated for 3A continuous load |
| Maximum Input Voltage | 40 V | 28 V (max) | LM2596S-12 supports higher input voltage, better for higher voltage rails |
| Minimum Input Voltage | 4.5 V | Not explicitly specified | LM2596S-12 min input 4.5 V, LM2596S-5.0-EV datasheet less clear |
| Switching Frequency (typical) | 150 kHz | 150 kHz | Equivalent switching frequency |
| Peak Current (max) | Not explicitly provided; typical 7.5 A (adjustable versions) | 6.9/7.5 A (max) | LM2596S-5.0-EV provides explicit peak current specs, similar range |
| Quiescent Current (typical) | 5 mA | 5 mA | Equivalent low quiescent current |
| Standby Current (typical) | 80 µA | 80 µA | Equivalent standby current |
| Feedback Bias Current (typical) | 100 nA | 10 nA | LM2596S-5.0-EV offers lower feedback bias current, improving accuracy and stability |
| Feedback Voltage (typical) | 1.23 V | Not explicitly specified | LM2596S-12 typical feedback voltage known; LM2596S-5.0-EV datasheet does not specify |
| Internal Switch Saturation Voltage | 1.4 V (typ) | 1.16 V (typ) | LM2596S-5.0-EV has slightly lower saturation voltage, potentially better conduction losses |
| Diode Type | 5 A, 40 V Schottky | Not explicitly specified; diode forward voltage 0.5 V | LM2596S-5.0-EV Schottky diode forward voltage specified, slightly lower than typical Schottky drop (0.5 V) |
| Inductor Value (typical) | 33 µH | 33 µH | Same inductance recommended |
| Inductor Max | Not explicitly specified | 68 µH | LM2596S-5.0-EV suggests higher max inductance for flexibility |
| Input Capacitor Size (typical) | 68 µF | 470 µF / 50 V (typ) | LM2596S-5.0-EV recommends larger input capacitor for improved stability |
| Input Capacitor Voltage Rating (typical) | Not specified | 25 V (min) | LM2596S-5.0-EV input capacitor voltage rating is explicit |
| Package | TO-263-6, D2PAK (5 leads + tab) | TO-263-6, D2PAK (5 leads + tab) | Equivalent package and pin count |
| Thermal Resistance TO-263 to Case | 50 °C/W | 20–50 °C/W (min 30, max 50) | LM2596S-5.0-EV datasheet lists a wide range; LM2596S-12 fixed at 50 °C/W |
| Operating Temperature Range | -40°C to 125°C (TJ) | Not explicitly specified | LM2596S-12 covers standard industrial range |
| Additional Resistor Required | 47 kΩ resistor if zener voltage > 25 V | Not specified | LM2596S-12 datasheet notes external resistor for high zener voltage clamp |
| Output Voltage Tolerance | ±4% | ±4% | Equivalent output accuracy |
| On/Off Pin Input Current (typical) | 5 µA | Not explicitly specified | LM2596S-12 shows detailed ON/OFF pin current specs |
| On/Off Pin Voltage Max | 25 V | Not specified | LM2596S-12 input pin voltage limit is clearly stated |
| Startup Time (min) | Not specified | 2 ms | LM2596S-5.0-EV data shows startup time |
| ESD Rating (HBM) | 2000 V (typ) | Not specified | LM2596S-12 ESD rating provided |
| RoHS Compliance | Yes | Not specified | LM2596S-12 RoHS compliance confirmed |
Design trade-offs
The primary design trade-off between the LM2596S-12/NOPB and LM2596S-5.0-EV is the fixed output voltage target: 12 V vs 5 V. This has cascading impacts on input voltage range, thermal dissipation, and component choice. The LM2596S-12 supports up to 40 V input, allowing use in higher-voltage rails such as 24 V or 36 V battery systems, whereas the LM2596S-5.0-EV limits max input to 28 V, making it less suitable for high voltage inputs without additional regulation or derating.
Thermally, both devices share the TO-263-6 package, but the LM2596S-5.0-EV datasheet specifies a broader thermal resistance range (20–50 °C/W), suggesting variability depending on board layout and heat sinking. The LM2596S-12’s specified 50 °C/W junction-to-ambient resistance sets a clear baseline for thermal calculations. Given the 3 A continuous output current and typical saturation voltages of around 1.16–1.4 V, expect conduction losses around 3.5–4.2 W at full load, which mandates careful copper area sizing and possibly a dedicated heat sink or thermal vias.
The feedback bias current is a notable difference: LM2596S-5.0-EV has a typical 10 nA bias current, significantly lower than LM2596S-12’s 100 nA. For precision output voltage regulation, especially in designs sensitive to feedback current leakage (e.g., high-impedance feedback dividers), the 5.0-EV variant may yield better voltage accuracy and stability.
The input capacitor recommendations differ markedly: the LM2596S-5.0-EV calls for a much larger input capacitor (typical 470 µF at 50 V), which improves input filtering and reduces voltage ripple but increases BOM cost and PCB area. The LM2596S-12’s recommended 68 µF capacitor is minimal but sufficient for many applications. This difference can impact startup behavior, transient response, and EMI.
The diode forward voltage is explicitly specified at 0.5 V for the LM2596S-5.0-EV, slightly lower than typical Schottky diode drops, which can improve efficiency marginally, especially at lower output voltages. The LM2596S-12 references a 5 A, 40 V Schottky diode but without a specific forward voltage figure, so expect similar but slightly higher conduction losses.
From a firmware and control perspective, the LM2596S-12 provides more detailed ON/OFF pin electrical characteristics and voltage limits, useful for robust power sequencing and system integration. The LM2596S-5.0-EV lists a shutdown voltage of 1.3 V at 25 °C but lacks some of the ON/OFF pin current details, so design margins should be verified in system-level testing.
Cost-wise, both devices use the same package and have similar output current ratings, so pricing at volume will likely be comparable. However, the larger recommended input capacitor for the 5.0-EV may slightly increase overall BOM cost for a given design.
Use-case fit
Choose LM2596S-12/NOPB when…
- Designing a 12 V power rail from a 24 V or 36 V automotive or industrial supply, requiring robust input voltage tolerance up to 40 V.
- You need to minimize external component count and BOM cost, given the lower input capacitor size recommendation.
- Thermal dissipation is a concern, and your layout or heat sinking can handle the specified 50 °C/W junction-to-ambient resistance.
- Your design requires clear ON/OFF pin input current specs and voltage limits for precise power sequencing.
- You want a proven, widely documented device with explicit zener resistor recommendations for high-voltage clamping.