Texas Instruments LM2588S-5.0

Overview

LM2588S-5.0 from Texas Instruments is a monolithic 5A flyback/boost switching regulator IC with fixed 5.0V output, integrated 5.0A NPN power switch rated for 65V standoff, 4V–40V input range, and adjustable 100–200 kHz switching frequency. It delivers up to 1.45A load current with ±4% system output voltage tolerance and supports external shutdown and frequency synchronization in industrial power supplies.

For engineers reviewing the LM2588S-5.0 datasheet, LM2588S-5.0 pinout, LM2588S-5.0 application, or LM2588S-5.0 equivalent, key selection criteria include its fixed 5.0V output configuration, TO-263-7 (KTW) package thermal performance (θ_JA = 35°C/W with 3.6× copper area), current-mode control architecture, and compatibility with standard flyback transformers like Schott 67141450 for single-output 5V designs.

Technical Context

The LM2588S-5.0 implements current-mode PWM control using an internal error amplifier (V_REF = 5.0V, AVOL = 165 V/V, GM = 0.75 mmho) and comparator that terminates switch conduction when sensed inductor current matches the error amp output ramp. Its oscillator supports resistor programming (R_SET = open → 100 kHz; R_SET = 22 kΩ → 200 kHz) and external synchronization via Pin 1.

Protection includes cycle-by-cycle current limiting (ICL = 5.0A min), thermal shutdown, undervoltage lockout (V_UV = 3.30V typ), and soft-start (ISS = 11.0 μA). The device draws <60 μA in shutdown and features an internal 5.0V reference tied to the feedback network-no external divider required for fixed-output versions.

Key Specifications

Pinout & Package

LM2588S-5.0 is housed in a 7-pin TO-263 (KTW) surface-mount package with exposed thermal pad, optimized for high-current thermal dissipation (θ_JA = 35°C/W with 3.6× copper area).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2588T-5.0, LM2588S-5.0 offers superior thermal performance in SMT production; compared with LM2577-5.0, it provides higher current capability, programmable frequency, and advanced protection-making it the optimal choice for demanding industrial flyback designs requiring reliability and design flexibility.

Availability

LM2588S-5.0 is available at Aetrix Electronics and suitable for industrial automation power supplies, automotive auxiliary DC-DC converters, and medical isolated bias rails requiring stable component supply and long-term lifecycle support.

Supply support for LM2588S-5.0 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 IC design and manufacturing.

The LM2588 series was developed specifically for cost-effective, high-reliability flyback and boost converter applications in industrial, automotive, and medical equipment-emphasizing integration, thermal robustness, and ease of use with minimal external components.

FAQ

What is the maximum output current achievable with LM2588S-5.0 in a flyback configuration?

The LM2588S-5.0 supports up to 1.45A output current under specified conditions (VIN = 12V, TJ ≤ 125°C), as confirmed in the LM2588-5.0 Electrical Characteristics table. This assumes proper transformer selection (e.g., Schott 67141450), adequate PCB copper area for thermal management (θ_JA = 35°C/W), and adherence to the recommended flyback test circuit in Figure 18. Exceeding this current risks thermal shutdown or reduced reliability.

Does LM2588S-5.0 require external feedback resistors to set the 5.0V output?

No, LM2588S-5.0 does not require external feedback resistors. As a fixed-output variant, it integrates an internal 5.0V reference directly connected to the FB pin-this pin must be left unconnected per the datasheet. External resistors are only needed for the adjustable LM2588-ADJ version, where R1 and R2 form a voltage divider to set VOUT = 1.23V × (1 + R1/R2).

Can LM2588S-5.0 be used in boost topology, and what are the key design considerations?

Yes, LM2588S-5.0 supports boost configuration as documented in Figure 47 and Figure 50. Key considerations include selecting an inductor rated for ≥5A DC current (e.g., Renco RL-5472-5), using a Schottky diode with ≥65V PIV and low forward drop (e.g., 1N5820), and ensuring input capacitance minimizes voltage sag during high-current pulses. Efficiency reaches 80% at 12V input/750mA load.

What is the purpose of the SYNC/ADJ pin (Pin 1) on LM2588S-5.0, and how is it configured for fixed-frequency operation?

The SYNC/ADJ pin (Pin 1) controls oscillator frequency: leaving it open sets f_O = 100 kHz; connecting a 22 kΩ resistor to GND sets f_O = 200 kHz. For fixed-frequency operation without external clocking, no connection is required-open-circuit is the default configuration. Applying an external clock signal (200 kHz max) synchronizes multiple LM2588S-5.0 devices to eliminate beat-frequency EMI.

How does the shutdown function of LM2588S-5.0 behave, and what voltage thresholds activate it?

The SHDN pin (Pin 7) enables logic-controlled shutdown: applying <0.8V (min) disables the internal switch and reduces supply current to <60 μA; applying >1.6V (min) enables normal operation. The threshold is specified as V_SHTH = 1.6V typical, with hysteresis to prevent chatter near the transition point. This allows direct interfacing with 3.3V or 5V microcontrollers without level-shifting.