LM2596S-ADJ/NOPB vs TGM-240NSLFTR: Component Comparison for Hardware Engineers
Quick verdict
For non-isolated, cost-sensitive 3A buck regulator designs running up to 40V input, the LM2596S-ADJ/NOPB is the straightforward choice due to its integrated controller, well-documented performance, and simpler BOM. For isolated DC/DC converter applications requiring galvanic isolation up to 1500Vrms and compatibility with Analog Devices MAX-series controllers, the TGM-240NSLFTR is the suitable magnetics component, but it is not a standalone regulator IC and requires external driver circuitry.
Spec comparison table
| Spec | LM2596S-ADJ/NOPB | TGM-240NSLFTR | Notes |
|---|---|---|---|
| Function | Step-Down Buck Regulator IC | Isolated Buck Converter Transformer | LM2596 is a complete IC; TGM-240NSLFTR is a transformer for isolated converters. |
| Input Voltage Max | 40 V | N/A | LM2596 supports up to 40V input. TGM-240NSLFTR is a transformer, no direct input rating. |
| Input Voltage Min | 4.5 V | N/A | LM2596 operates down to 4.5V input. |
| Mounting Type | Surface Mount | Surface Mount | Both are surface mount, suitable for automated assembly. |
| Number of Outputs | 1 | N/A | LM2596 has one regulated output; TGM-240NSLFTR is a component, no output per se. |
| Operating Temperature Range | -40°C to 125°C (TJ) | -40°C to 85°C | LM2596 has a wider temperature range, better suited for higher TJ applications. |
| Output Configuration | Positive | N/A | LM2596 provides positive output regulation. |
| Output Current Max | 3 A | N/A | LM2596 can supply up to 3A; TGM-240NSLFTR is a transformer, current depends on design. |
| Output Type | Adjustable | N/A | LM2596 output voltage adjustable from 1.2V to 37V. |
| Output Voltage Max | 37 V | N/A | LM2596 output voltage max is 37V. |
| Output Voltage Min | 1.2 V | N/A | LM2596 minimum regulated output voltage is 1.2V. |
| Package Case | TO-263-6, D2PAK (5 Leads + Tab) | N/A | LM2596 is a packaged IC; TGM-240NSLFTR is a discrete magnetics component. |
| Supplier Device Package | TO-263 (DDPAK-5) | N/A | Same as above. |
| Switching Frequency Typ | 150 kHz | N/A | LM2596 switching frequency is fixed at 150kHz typical. |
| Synchronous Rectifier | No | N/A | LM2596 uses an external diode for synchronous rectification. |
| Topology | Buck | Buck (Isolated) | LM2596 is a non-isolated buck regulator; TGM-240NSLFTR is for isolated buck converters. |
| DCR Max | N/A | 0.8 Ω | TGM-240NSLFTR coil DCR max is 0.8Ω; affects efficiency and losses. |
| Footprint | N/A | 8.13mm x 7.11mm | Only TGM-240NSLFTR footprint provided. |
| Height Seated Max | N/A | 5.08 mm (0.200”) | TGM-240NSLFTR height relevant for mechanical constraints. |
| Intended Chipset | N/A | Analog Devices MAX253, MAX845, MAX3535, MXL1535 | TGM-240NSLFTR designed for use with these Analog Devices controllers. |
| Isolation Voltage Max | N/A | 4500 Vrms | TGM-240NSLFTR provides galvanic isolation up to 4500Vrms max. |
| Isolation Voltage Min | N/A | 1500 Vrms | Isolation guaranteed at minimum 1500Vrms. |
| Isolation Voltage Typ | N/A | 1500 Vrms | Typical isolation rating. |
| Primary Inductance Min | N/A | 960 μH | TGM-240NSLFTR primary inductance, important for converter design. |
| Primary Inductance Typ | N/A | 960 μH | Same as min value. |
| Secondary Inductance Min | N/A | 960 μH | Secondary inductance, matches primary, critical for isolation and energy transfer. |
| Secondary Inductance Typ | N/A | 960 μH | Same as min value. |
| Switching Frequency Max | N/A | 11 V-μs | TGM-240NSLFTR rated for a max switching voltage-time product, relevant for driver design. |
| Temperature Range Max | 125°C | 85°C | LM2596 supports higher max temperature. |
| Temperature Range Min | -40°C | -40°C | Both support -40°C minimum operating temperature. |
| Turns Ratio Primary-Secondary | N/A | ±3% | Tight turns ratio tolerance ±3% helps stable voltage ratios in isolated designs. |
Design trade-offs
The LM2596S-ADJ/NOPB is a monolithic switching regulator IC integrating the control logic, power switch, and feedback compensation, leaving the designer to select only a minimal external inductor, diode, and capacitors. Its 150kHz switching frequency is a compromise between efficiency and component size, allowing reasonably compact inductors while keeping switching losses manageable. Its TO-263 package supports up to 3A output current with a thermal rating suitable for moderate power levels, and the junction temperature range up to 125°C provides margin for operation in harsh environments.
In contrast, the TGM-240NSLFTR is a discrete transformer component intended for isolated buck converter topologies, not a regulator IC itself. It requires an external controller IC (such as Analog Devices MAX253 or MAX845) to drive it. This transformer enables galvanic isolation up to 1500Vrms (typical) with a maximum of 4500Vrms, critical in medical, industrial, or telecom applications where isolation is mandated. The transformer’s relatively high DCR (0.8Ω max) will contribute to conduction losses, so efficiency depends heavily on the external driver and switching scheme.
Thermally, the LM2596’s integrated package and known power dissipation curves make it easier to estimate and manage heat via PCB copper area and heatsinking. The TGM-240NSLFTR’s thermal performance is less straightforward; losses are distributed through copper windings and core, requiring careful layout and possibly thermal vias or copper pours. The TGM-240NSLFTR’s 5.08mm height and 8.13 x 7.11 mm footprint are modest but significantly larger than typical small inductors, which impacts PCB real estate and stacking options.
From a firmware perspective, the LM2596 requires minimal control – it is a fixed frequency, voltage-mode regulator with simple feedback. The TGM-240NSLFTR, being a magnetics component, demands a compatible controller IC and more complex firmware to handle isolated feedback loops, potentially including secondary-side sensing and communication.
Cost-wise, the LM2596 is a single IC solution with a few discrete passives, commonly available and inexpensive in volume. The TGM-240NSLFTR, as a specialized isolated transformer, is more expensive and usually paired with higher-cost controllers, increasing overall BOM cost and complexity.
Use-case fit
Choose LM2596S-ADJ/NOPB when…
- Designing a non-isolated buck regulator with up to 3A load current and input voltages from 4.5V to 40V.
- You need a simple, well-documented, single-chip solution with adjustable output voltage down to 1.2V.
- The application requires operation up to 125°C junction temperature, such as automotive or rugged industrial environments.
- PCB space is limited and you want a compact TO-263 package with minimal external components.
- You want a fixed switching frequency regulator with no need for synchronous rectification and easy layout guidelines.
Choose TGM-240NSLFTR when…
- Your design requires galvanic isolation of at least 1500Vrms between input and output rails.
- You are using Analog Devices MAX-series isolated DC/DC controller ICs compatible with this transformer.
- The system must meet medical, industrial, or communication standards that mandate isolation.
- You are prepared to implement more complex firmware and hardware to manage isolated feedback and drive signals.
- Your design can accommodate the larger component size and higher thermal management challenges of an isolated transformer.
Drop-in compatibility
These two parts are not pin-compatible or footprint-compatible. The LM2596S-ADJ/NOPB is a fully integrated buck converter IC in a TO-263 package, whereas the TGM-240NSLFTR is a discrete transformer component with a different footprint and pinout designed to be used alongside specific Analog Devices