Texas Instruments LM2596S-5.0/NOPB

Overview

LM2596S-5.0/NOPB from Texas Instruments is a monolithic nonsynchronous step-down DC-DC converter delivering 5 V at up to 3 A output current, operating at a fixed 150-kHz switching frequency with ±4% output voltage tolerance over line and load, and featuring TTL-compatible ON/OFF control for system-level power sequencing in industrial power supplies.

For engineers reviewing the LM2596S-5.0/NOPB datasheet, LM2596S-5.0/NOPB pinout, LM2596S-5.0/NOPB application, or LM2596S-5.0/NOPB equivalent, key selection criteria include input voltage range (4.5–40 V), thermal performance in TO-263 package, shutdown quiescent current (80 µA typical), and compatibility with standard off-the-shelf inductors in buck topology designs.

Technical Context

The LM2596S-5.0/NOPB integrates a PWM controller, power switch, and internal frequency compensation in a single chip, enabling fixed-output buck conversion without external feedback resistors. Its 150-kHz oscillator allows use of compact, low-cost filter components while maintaining stable regulation across –40°C to +125°C junction temperature.

It operates in continuous conduction mode by default, supports discontinuous mode at light loads, and implements two-stage current limiting plus thermal shutdown for fault protection. The ON/OFF pin provides logic-level shutdown with 1.3-V threshold and 80-µA standby current, enabling precise system power gating.

Key Specifications

Pinout & Package

LM2596S-5.0/NOPB is housed in a 5-pin TO-263 (KTT) surface-mount package with exposed thermal pad, offering improved thermal resistance (R_θJA = 20°C/W with 3 in² double-sided copper) versus TO-220 alternatives.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down regulator applications.

Compared with LM2596S-5.0/NOPB, LM2596T-5.0 offers identical regulation performance in a through-hole package for easier thermal management on non-PCB-mounted heatsinks, while LMR51430RGER delivers superior efficiency and integration at the cost of increased design complexity and loss of pin compatibility.

Availability

LM2596S-5.0/NOPB is available at Aetrix Electronics and suitable for industrial power supplies, embedded control systems, home theater AV receivers, and grid infrastructure sensor nodes requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LM2596S-5.0/NOPB includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management technologies, with decades of expertise in high-reliability power conversion ICs.

The LM2596 series belongs to TI's SIMPLE SWITCHER® portfolio, designed specifically for cost-sensitive, medium-power DC-DC applications where ease of use, robustness, and minimal external component count are critical.

FAQ

What is the maximum input voltage rating for LM2596S-5.0/NOPB?

The absolute maximum input voltage for LM2596S-5.0/NOPB is 45 V, but the recommended operating range is 4.5 V to 40 V. Exceeding 40 V may trigger internal protection or degrade long-term reliability. Designers should ensure transient suppression (e.g., TVS diode) is used if the source can exceed 40 V, as the device lacks built-in overvoltage clamping beyond this limit. LM2596S-5.0/NOPB maintains regulation and protection functionality within its specified 4.5–40 V window.

Does LM2596S-5.0/NOPB require external feedback resistors?

No, LM2596S-5.0/NOPB does not require external feedback resistors because it integrates a precision 5-V reference and internal resistor divider for fixed-output regulation. Pin 4 (FEEDBACK) is internally connected and must be left unconnected or grounded per the datasheet - adding external resistors will disrupt regulation and cause output inaccuracy. This simplifies design and improves accuracy versus adjustable versions. LM2596S-5.0/NOPB leverages its monolithic feedback network to achieve ±4% output tolerance without user calibration.

What package type is used for LM2596S-5.0/NOPB?

LM2596S-5.0/NOPB uses the 5-pin TO-263 (KTT) surface-mount package with an exposed thermal pad, measuring 10.10 mm × 8.89 mm. This thermally enhanced package achieves R_θJA = 20°C/W with proper double-sided copper layout, significantly outperforming the TO-220 variant in SMT applications. The KTT package supports reflow soldering and enables compact, high-density power stage layouts. LM2596S-5.0/NOPB's thermal pad must be soldered to a minimum 3 in² copper area for optimal thermal performance.

Can LM2596S-5.0/NOPB be used in inverting (negative-output) configurations?

Yes, LM2596S-5.0/NOPB can be configured as an inverting regulator to generate –5 V from a positive input, as documented in TI's SNVS124G datasheet Figure 8-5. This requires bootstrapping the GND pin to the negative output and grounding the FEEDBACK pin. However, startup current surges (up to 4.5 A) and modified ON/OFF threshold (~13 V) apply. LM2596S-5.0/NOPB retains all protection features in this topology but demands careful input capacitance sizing and optional delayed start-up circuitry.

What is the typical efficiency of LM2596S-5.0/NOPB at full load?

LM2596S-5.0/NOPB delivers 80% typical efficiency at 12-V input and 3-A output load, as measured per the standard test circuit in Section 7.6 of the datasheet. Efficiency rises with higher input voltages (e.g., >90% at 24-V input/3-A for 12-V versions) and falls at light loads due to fixed switching losses. Real-world efficiency depends on external component selection - especially Schottky catch diode VF and inductor DCR - and PCB thermal design. LM2596S-5.0/NOPB's efficiency enables thermally constrained applications without forced air cooling.