Texas Instruments LM2586T-5.0/NOPB

Overview

LM2586T-5.0/NOPB from Texas Instruments is a monolithic 3-A step-up (boost) and flyback switching regulator IC with fixed 5.0 V output, 4 V to 40 V input range, internal 3-A NPN switch rated for 65 V standoff, current-mode control, and soft-start. It enables compact, cost-effective DC/DC conversion in industrial power supplies and battery-powered systems requiring regulated 5 V at up to 1.1 A load.

For engineers reviewing the LM2586T-5.0/NOPB datasheet, LM2586T-5.0/NOPB pinout, LM2586T-5.0/NOPB application, or LM2586T-5.0/NOPB equivalent, key selection criteria include input voltage range compatibility, output current capability under thermal constraints, shutdown functionality, frequency adjust/sync capability, and TO-220 package thermal performance in high-reliability power designs.

Technical Context

The LM2586T-5.0/NOPB integrates a current-mode PWM controller with an internal 3-A NPN power switch capable of 65 V blocking. Its error amplifier compares feedback voltage against a 5.0 V reference (±4% system tolerance), generating a compensation signal that modulates peak switch current via cycle-by-cycle current limiting.

It supports adjustable switching frequency (100–200 kHz) via external resistor on Pin 1 and synchronization via negative-edge pulses on Pin 6. Protection includes undervoltage lockout (3.3 V threshold), thermal shutdown, and current limiting-enabling robust operation in flyback, boost, and forward converter topologies without external current-sense components.

Key Specifications

Pinout & Package

LM2586T-5.0/NOPB is housed in a 7-pin TO-220 (NDZ) package with bent, staggered leads and exposed metal tab electrically connected to Pin 2 (Ground). The tab must be thermally coupled to a heatsink for sustained 3-A operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-up/flyback regulator applications.

Compared with LM2586T-5.0/NOPB, LM2587T-5.0/NOPB offers tighter flyback cross-regulation while TPS55340RTER provides higher integration and frequency in a surface-mount package - making LM2586T-5.0/NOPB optimal for through-hole, thermally demanding, or multi-device synchronized boost/flyback systems.

Availability

LM2586T-5.0/NOPB is available at Aetrix Electronics and suitable for industrial automation power supplies, automotive body electronics, medical portable equipment, and telecom remote units requiring stable component supply and long-term manufacturability.

Supply support for LM2586T-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 and embedded processing technologies, with decades of expertise in power management ICs for industrial, automotive, and communications markets.

The LM2586 series was designed specifically for cost-sensitive, high-reliability flyback, boost, and forward converter applications - targeting engineers who require monolithic integration, wide input range, and robust protection without sacrificing design flexibility.

FAQ

What is the maximum output current achievable with LM2586T-5.0/NOPB in boost configuration?

The LM2586T-5.0/NOPB datasheet specifies 1.1 A maximum output current in boost mode at VIN = 12 V, based on thermal limits and internal 3-A switch capability. Output current is constrained by power dissipation in the TO-220 package - sustained operation above 1 A requires adequate heatsinking and airflow. At lower input voltages (e.g., 5 V), output current drops due to duty cycle and efficiency limitations.

Can LM2586T-5.0/NOPB be used in flyback topology with transformer isolation?

Yes, LM2586T-5.0/NOPB is explicitly designed for flyback operation, as confirmed in its product description and typical applications. It supports transformer-isolated outputs with primary-side regulation, and the internal 65 V switch withstands reflected voltages common in 5 V flyback designs. The datasheet includes complete flyback reference schematics and transformer selection guidance for LM2586T-5.0/NOPB.

Does LM2586T-5.0/NOPB require external components for feedback in fixed 5 V operation?

No, LM2586T-5.0/NOPB has an internally trimmed 5.0 V reference and does not require external feedback resistors. Pin 3 (Feedback) remains unconnected in this variant. The fixed output is achieved via on-die resistor networks calibrated to deliver 5.0 V ±4% across line, load, and temperature - eliminating tuning effort and improving long-term stability versus adjustable versions.

How does the shutdown function work on LM2586T-5.0/NOPB?

LM2586T-5.0/NOPB uses Pin 1 (Freq Adj / ON-OFF) for shutdown: applying ≥3 V to this pin forces the IC into low-power state, reducing total supply current to ~56 μA. An isolation diode is required in series to prevent backfeeding. During shutdown, the switch is disabled, compensation pin is clamped, and output voltage collapses - enabling precise system-level power sequencing in multi-rail applications.

What thermal considerations apply to LM2586T-5.0/NOPB in TO-220 package?

LM2586T-5.0/NOPB in TO-220 (NDZ) has θ_JA = 65°C/W with minimal copper and no heatsink. For 3-A switch operation, thermal design must ensure junction temperature stays below 125°C. Recommended practices include mounting the exposed tab to ≥2 in² of 1 oz. copper with thermal vias, using thermal interface material, and verifying temperature rise under worst-case load and ambient conditions per TI's SLVA297 application report.