Texas Instruments LM2588S-3.3

Overview

LM2588S-3.3 from Texas Instruments is a monolithic 5A flyback/boost switching regulator IC with fixed 3.3V output, integrated 5.0A NPN power switch rated for 65V standoff, wide 4V–40V input range, adjustable 100–200kHz switching frequency, and external shutdown capability. It delivers up to 1.75A load current with ±4% system output voltage tolerance across line and load conditions in flyback or boost topologies.

For engineers reviewing the LM2588S-3.3 datasheet, LM2588S-3.3 pinout, LM2588S-3.3 application, or LM2588S-3.3 equivalent, this page provides verified technical context, real-world design parameters, package-specific thermal data, functional alternatives, and supply-chain support details for industrial power conversion designs.

Technical Context

The LM2588S-3.3 implements current-mode control with cycle-by-cycle current limiting, internal soft-start (11 μA soft-start current), and an error amplifier featuring 1.193 mmho transconductance and 260 V/V open-loop gain. Its oscillator supports frequency adjustment via external resistor or synchronization to external clock signals.

Protection includes thermal shutdown, undervoltage lockout (3.30V threshold), overcurrent limiting (6.5A typical switch current limit), and switch saturation voltage of 0.7V at 5.0A. The device operates from −40°C to +125°C junction temperature and draws less than 60 μA in shutdown mode.

Key Specifications

Pinout & Package

The LM2588S-3.3 is housed in a 7-pin TO-263 (KTW) surface-mount package with exposed thermal pad, optimized for high-current switching applications requiring efficient heat dissipation on PCBs with ≥0.4896 in² copper area (θJA = 35°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar flyback/boost regulator applications.

Compared with LM2587S-3.3, the LM2588S-3.3 delivers 43% higher switch current and adds synchronization - critical for noise-sensitive multi-rail systems. Versus UC3845BD1R2G, it trades design flexibility for integration, reducing bill-of-materials by ~7 components and eliminating gate-drive layout risks.

Availability

LM2588S-3.3 is available at Aetrix Electronics and suitable for industrial power supplies, automotive electronics, telecom infrastructure, and programmable logic controllers requiring stable component supply and long-term manufacturability.

Supply support for LM2588S-3.3 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 LM2588 series was designed specifically for cost-effective, low-component-count flyback and boost regulators targeting industrial, automotive, and telecom power systems - emphasizing integration, protection, and ease of use.

FAQ

What is the maximum output current supported by the LM2588S-3.3 in flyback configuration?

The LM2588S-3.3 supports up to 1.75A output current in flyback configuration, as specified in its electrical characteristics table under "Load Regulation" conditions. This value assumes proper thermal management using the KTW package with ≥0.4896 in² copper area (θJA = 35°C/W) and adherence to the reference design in Figure 18. Output current is internally limited in flyback mode, unlike boost mode where external current limiting is required to protect the 5.0A NPN switch.

Does the LM2588S-3.3 require external feedback resistors to set the output voltage?

No, the LM2588S-3.3 does not require external feedback resistors. It features a factory-trimmed internal 3.3V reference connected directly to the FEEDBACK pin, enabling fixed-output operation without external divider networks. This simplifies design, improves accuracy (±4% system tolerance), and reduces component count compared to adjustable versions like LM2588S-ADJ, which require precision resistor pairs.

Can the LM2588S-3.3 be used in boost topology, and what are the key constraints?

Yes, the LM2588S-3.3 can be configured as a boost regulator, as shown in Figure 47 of the datasheet. Key constraints include externally limiting output current to ≤5A to prevent switch damage (since output current is not internally limited in boost mode), selecting an inductor with appropriate saturation current (e.g., Renco RL-5472-5), and ensuring input voltage remains within 4V–40V. Efficiency reaches 75% at 12V input and 1A load per test data.

What thermal derating applies to the LM2588S-3.3 in the KTW package at elevated ambient temperatures?

In the KTW (TO-263) package with 0.4896 in² copper area, the LM2588S-3.3 has θJA = 35°C/W. At 70°C ambient, maximum allowable power dissipation is PD ≤ (150°C − 70°C)/35°C/W = 2.29W. Derating curves in the datasheet confirm continuous 5A switch operation is viable up to 85°C ambient with adequate board copper - exceeding typical industrial requirements without forced air cooling.

How does the SYNC pin function on the LM2588S-3.3, and what voltage levels trigger synchronization?

The SYNC pin on the LM2588S-3.3 accepts an external clock signal to synchronize switching frequency across multiple devices. Synchronization triggers when the applied voltage crosses the threshold of 0.625V (min) to 0.875V (max) at 200kHz, with typical threshold at 0.75V. Input current is 100 μA max, allowing direct connection to CMOS logic outputs or dedicated sync generators - eliminating beat frequencies in multi-regulator systems.