STMicroelectronics L6928D

Overview

L6928D from STMicroelectronics is a monolithic synchronous step-down DC-DC regulator in TSSOP8 package, designed for single-cell Li-Ion battery-powered systems (2 V–5.5 V input), delivering up to 800 mA output current with adjustable voltage down to 0.6 V, ±1% accuracy, and 1.4 MHz fixed-frequency current-mode control. It integrates high- and low-side MOSFETs, supports 100% duty-cycle dropout operation, and includes Power Good, OVP, short-circuit, and thermal shutdown protections.

For engineers reviewing the L6928D datasheet, L6928D pinout, L6928D application, or L6928D equivalent, this page provides verified technical context on low-noise/low-consumption mode selection via SYNC pin, COMP compensation requirements, PGOOD open-drain behavior, and real-world efficiency trade-offs between light-load modes - critical for portable instrument and handheld terminal power design.

Technical Context

The L6928D implements a slope-compensated current-mode PWM architecture with internal 1.4 MHz oscillator and external synchronization capability (1–2 MHz). Its dual operating modes-low-consumption (SYNC ≥1.3 V) and low-noise (SYNC ≤0.5 V)-are hardware-selectable and affect switching behavior, valley current limits (1.4 A typ.), and quiescent current (25 µA vs. 230 µA).

It features integrated protection logic: hard OVP triggers at +10% VFB, short-circuit response uses both peak (1.2 A typ.) and valley (1.4 A typ.) current limits, and thermal shutdown activates at 150 °C with hysteresis restart at 95 °C. The error amplifier references 0.6 V with 25 nA input bias and drives COMP for loop compensation.

Key Specifications

Pinout & Package

TSSOP8 package (3 mm × 3 mm × 1.0 mm, ECOPACK® compliant) with exposed thermal pad (E-pad) requiring GND connection for optimal thermal performance (R_thJA = 180 °C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS62231DRVR and MAX17502ETA+, the L6928D uniquely balances Li-Ion compatibility (2–5.5 V), integrated protections, selectable light-load modes, and TSSOP8 manufacturability - making it optimal for cost-sensitive, battery-life-critical handheld designs where component count and thermal performance matter.

Availability

L6928D is available at Aetrix Electronics and suitable for cellular phones, portable instruments, PDAs and handheld terminals, and DSC/GPS modules requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for L6928D 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, specializing in power management, microcontrollers, and analog ICs for automotive, industrial, and consumer markets.

The L6928D belongs to ST's high-efficiency DC-DC converter product line, engineered specifically for battery-powered portable electronics requiring minimal external components, robust protection, and seamless integration into space- and power-constrained designs.

FAQ

What is the minimum recommended output capacitor for stable L6928D operation?

The datasheet specifies a 10 µF ceramic output capacitor (X5R/X7R, 6.3 V rating) as standard for stability and transient response. Using lower-ESR MLCCs is mandatory; aluminum or tantalum capacitors are not recommended due to insufficient high-frequency response. Layout must minimize trace inductance between LX, GND, and C_OUT to prevent oscillation.

How does the SYNC pin affect efficiency at 10 mA load?

At 10 mA load, low-consumption mode (SYNC ≥1.3 V) achieves ~88% efficiency with 25 µA quiescent current and discontinuous conduction, while low-noise mode (SYNC ≤0.5 V) drops to ~76% efficiency with 230 µA quiescent current and forced 1.4 MHz switching. Efficiency difference arises from reduced switching losses in discontinuous mode.

Can the L6928D regulate output when input drops to 2.1 V?

Yes - the L6928D supports 2 V minimum input and operates down to 100% duty cycle. At V_IN = 2.1 V and V_OUT = 1.8 V, dropout is limited by R_DS(on) of internal MOSFETs (240 mΩ high-side, 215 mΩ low-side), resulting in ~120 mV dropout at 100 mA, enabling functional regulation until battery depletion.

Is the E-pad on the TSSOP8 package electrically connected internally?

No - the E-pad is a thermal pad only, not connected to any internal circuit. It must be soldered to a dedicated PCB GND copper pour using ≥4 thermal vias (0.3 mm diameter) to achieve the specified R_thJA = 180 °C/W and prevent thermal shutdown during 800 mA continuous operation.