STMicroelectronics L6926Q1TR

Overview

L6926Q1TR from STMicroelectronics is a monolithic synchronous step-down DC-DC regulator in VFQFPN8 (3×3×1.0 mm) package, designed for single Li-Ion battery-powered systems. It delivers up to 800 mA output current with adjustable output voltage from 0.6 V, supports 2–5.5 V input range, achieves up to 95% efficiency, and features 600 kHz fixed-frequency current-mode control with external synchronization capability (500 kHz–1.4 MHz).

For engineers reviewing the L6926Q1TR datasheet, L6926Q1TR pinout, L6926Q1TR application, or L6926Q1TR equivalent, key selection considerations include its low-quiescent-current operation (25 µA typ. in low-consumption mode), ±1% output voltage accuracy, Power Good signal, 100% duty-cycle dropout capability, and integrated high- and low-side MOSFETs eliminating external Schottky diode requirements.

Technical Context

The L6926Q1TR implements a slope-compensated current-mode PWM controller with internal 0.6 V reference and dual operating modes selected via SYNC pin: low-consumption mode (discontinuous conduction at light load, 25 µA IQ) and low-noise mode (forced 600 kHz switching). It integrates peak and valley current limiting (1.2 A typ. peak, 1.4 A typ. valley) and zero-crossing detection for robust short-circuit protection.

Its loop stability relies on COMP pin compensation (typically 220 pF to GND), while thermal shutdown activates at 150 °C and recovers at 95 °C. The device supports 100% duty cycle for ultra-low dropout and includes OVP triggered at +10% VFB, PGOOD with 90% VOUT threshold and 4% hysteresis, and UVLO with 100 mV hysteresis.

Key Specifications

Pinout & Package

VFQFPN8 package (3 mm × 3 mm × 1.0 mm, exposed thermal pad), RoHS-compliant, ECOPACK®2 rated. E-pad must be soldered to PCB ground plane for optimal thermal performance (R_thJA = 56 °C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS62231DRYT and MAX17502ATP+, the L6926Q1TR uniquely combines Li-Ion-compatible input range, fully adjustable output, integrated synchronous switches, PGOOD, and selectable light-load modes - making it optimal for compact, battery-sensitive portable electronics where flexibility and efficiency coexist.

Availability

L6926Q1TR is available at Aetrix Electronics and suitable for portable medical sensors, GPS receivers, digital still cameras, and industrial handheld terminals requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for L6926Q1TR 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 microcontrollers, power management ICs, sensors, and analog chips for automotive, industrial, and consumer markets.

The L6926 series belongs to ST's high-efficiency DC-DC converter product line, engineered specifically for space- and battery-constrained portable electronics requiring wide-input, low-IQ, and robust protection features in miniature packages.

FAQ

What is the minimum input voltage required to start up the L6926Q1TR?

The L6926Q1TR has a typical turn-on threshold of 2.2 V and guaranteed operation down to 2.0 V after startup. Its UVLO hysteresis is 100 mV, meaning it remains active until input falls below ~2.1 V, then disables until input rises above 2.2 V again - ensuring clean power sequencing in Li-Ion battery applications.

Can the L6926Q1TR operate without an external compensation network on the COMP pin?

No. The COMP pin requires an external compensation network - typically a 220 pF capacitor to GND - to ensure loop stability across all operating conditions. Omitting this causes subharmonic oscillation or instability, especially at high duty cycles (>50%). A series resistor (e.g., 50 kΩ) may be added for improved transient response with low-ESR ceramic output capacitors.

How does the PGOOD signal behave during startup and fault conditions?

PGOOD is an open-drain output that remains high-impedance (floating) until VOUT reaches ≥90% of the target voltage, then pulls low if VOUT drops below that threshold. During startup, it stays high-impedance until regulation is achieved; during overvoltage or short-circuit, it asserts low continuously. No external pull-down is needed - only a pull-up resistor to VOUT or VCC.

Is the VFQFPN8 package of L6926Q1TR compatible with standard reflow profiles?

Yes. The VFQFPN8 package is RoHS-compliant and qualified for standard lead-free reflow profiles (J-STD-020). Peak temperature must not exceed 260 °C for ≤30 seconds. The exposed E-pad must be fully soldered to a thermal pad on the PCB with ≥60% solder coverage to achieve specified R_thJA = 56 °C/W and prevent thermal derating.