STMicroelectronics L6725TR

Overview

L6725TR from STMicroelectronics is a voltage-mode PWM buck controller for synchronous step-down DC-DC conversion, supporting input voltages from 1.8V to 18V and delivering adjustable output down to 0.6V with ±0.8% accuracy over temperature (0°C–125°C). It integrates high-current gate drivers (RHGATE_ON = 1.7Ω, RLGATE_OFF = 0.6Ω), predictive anti-cross-conduction control, and dual R_DS(on)-based overcurrent protection (peak and valley) for robust 20A+ power stages in low-voltage distributed systems such as GPU VRMs.

For engineers reviewing the L6725TR datasheet, L6725TR pinout, L6725TR application, or L6725TR equivalent, key selection considerations include its 250/500 kHz selectable switching frequency, bootstrap anti-discharging system, pre-bias startup capability, and SO16N package compatibility with high-density PCB layouts in graphics card and server VRM designs.

Technical Context

The L6725TR implements fixed-frequency voltage-mode control with 0–100% duty cycle support and oscillator accuracy of ±5% at both 250 kHz and 500 kHz. Its error amplifier delivers 10 MHz GBWP and 5 V/µs slew rate, enabling fast transient response in high-bandwidth converters.

Current sensing uses MOSFET R_DS(on) on both high-side and low-side paths-programmable via external resistors on OCH (peak limit) and OCL (valley limit) pins-with masking times of 100 ns and 500 ns respectively. Protection includes hiccup-mode OCP post-soft-start, thermal shutdown (150°C trip, 120°C recovery), and overvoltage protection triggered at 120% of V_FB.

Key Specifications

Pinout & Package

Package: SO16N (narrow-body 16-pin SOIC, 1.27 mm pitch, 10.3 mm × 7.5 mm footprint).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck controller applications.

Compared with ISL6263CRZ-T and TPS40303DRCR, the L6725TR uniquely combines SO16N manufacturability, dual R_DS(on) OCP, bootstrap anti-discharge, and pre-bias startup-making it optimal for rugged, high-current, single-phase VRMs where reliability and layout simplicity outweigh multi-phase complexity.

Availability

L6725TR is available at Aetrix Electronics and suitable for graphics card VRMs, server CPU core supplies, and industrial PLC I/O power systems requiring stable component supply, long-term lifecycle assurance, and traceable sourcing for volume production.

Supply support for L6725TR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, microcontroller, power, and sensor solutions for automotive, industrial, and consumer markets.

The L6725TR belongs to ST's high-performance power management IC portfolio, engineered specifically for synchronous buck DC-DC controllers in demanding computing and telecom infrastructure applications where precision regulation, thermal resilience, and MOSFET R_DS(on)-based protection are critical.

FAQ

What is the minimum achievable output voltage with the L6725TR, and how is accuracy maintained?

The L6725TR supports output voltages down to 0.6 V with ±0.8% accuracy over line, load, and temperature (0°C to 125°C). This is achieved using an internal trimmed 0.6 V reference and a high-gain error amplifier (100 dB open-loop gain, 10 MHz GBWP), ensuring tight regulation even under fast load transients and varying input conditions.

Does the L6725TR support pre-biased output startup, and how is it implemented?

Yes, the L6725TR supports pre-biased startup. During soft-start, the low-side MOSFET is enabled before the high-side, allowing controlled sinking of current from a pre-charged output. The SS/INH pin's inhibit function and current-limited soft-start ramp (10 µA after 0.5 V) prevent reverse current flow and ensure monotonic voltage rise without output collapse.

How does the bootstrap anti-discharging system improve performance in low-duty-cycle applications?

The bootstrap anti-discharging system actively maintains charge on the BOOT-to-PHASE capacitor during extended low-duty cycles (e.g., 1 V output from 12 V input). It prevents boot voltage collapse that would otherwise disable the high-side driver, enabling stable operation at duty cycles below 5%-critical for high-step-down VRMs in modern processors and GPUs.

Can the L6725TR be used without an external current-sense resistor, and what are the trade-offs?

Yes-the L6725TR eliminates external sense resistors by using high-side and low-side MOSFET R_DS(on) for peak and valley current limiting, configured via OCH and OCL pins. Trade-offs include sensitivity to MOSFET R_DS(on) variation over temperature, mitigated by ±5% OCP tolerance and dual-threshold architecture that ensures robustness across process and thermal corners.