STMicroelectronics A6727TR

Overview

A6727TR from STMicroelectronics is a single-phase synchronous buck PWM controller with integrated high-current MOSFET drivers, designed for automotive DC-DC conversion. It operates from 5 V to 12 V supply, supports input as low as 1.5 V, delivers ±1% output voltage accuracy via 0.8 V internal reference, and features fixed 300 kHz switching frequency, sensorless R_DS(on)-based overcurrent protection, and SO-8 package.

For engineers reviewing the A6727TR datasheet, A6727TR pinout, A6727TR application, or A6727TR equivalent, this device is selected for automotive power rails requiring AEC-Q100 compliance, pre-bias startup capability (LS-less), FB disconnection safety, and compact high-efficiency step-down control without external current-sense resistors.

Technical Context

The A6727TR implements voltage-mode control with a 15 MHz gain-bandwidth error amplifier and 8 V/µs slew rate, enabling fast transient response in automotive power supplies. Its adaptive deadtime control monitors PHASE and LGATE to prevent shoot-through while supporting negative inductor current recirculation via watchdog logic.

Overcurrent protection uses low-side R_DS(on) sensing with programmable threshold (50–500 mV) when V_CC = 5 V, or fixed −400 mV threshold when V_CC > 8 V. Protection responses include hiccup mode (13.6 ms period) and automatic soft-start restart after fault clearance.

Key Specifications

Pinout & Package

Package: SO-8 (Small Outline, 8-pin, 150 mil width), RoHS-compliant, rated for 85 °C/W junction-to-ambient thermal resistance on 2S2P board.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ4312-AEC1 and LM5143A-Q1, the A6727TR offers simpler voltage-mode design, guaranteed 300 kHz EMI behavior, and lowest component count for ≤6 A single-phase automotive rails-making it optimal for cost-sensitive, space-constrained modules where AEC-Q100 Grade 1 and LS-less startup are mandatory.

Availability

A6727TR is available at Aetrix Electronics and suitable for ADAS camera modules, infotainment SoC power supplies, and body control module I/O rails requiring stable component supply, AEC-Q100 compliance, and long-term automotive lifecycle support.

Supply support for A6727TR 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, specializing in automotive, industrial, and power management ICs with broad manufacturing and quality certification infrastructure.

The A6727TR belongs to ST's automotive-grade DC-DC controller product line, engineered specifically for reliable, compact, and cost-optimized synchronous buck conversion in harsh-temperature vehicle environments.

FAQ

Can A6727TR operate with input voltage below 5 V?

Yes. The A6727TR supports power conversion input down to 1.5 V, independent of its 5–12 V V_CC supply range. This enables use in low-VIN applications such as post-regulated 3.3 V or 2.5 V intermediate buses, provided the V_CC supply remains within specification and duty cycle limits are observed.

How does LS-less startup prevent negative output voltage spikes?

During LS-less startup, the low-side driver remains disabled until the high-side begins switching. If the output is pre-biased above the target voltage, the high-side stays off and the low-side activates only after soft-start completes-discharging the output safely. This avoids reverse inductor current flow and associated negative voltage excursions at the load.

What happens if FB pin is left unconnected?

The A6727TR sources a 100 nA current from the FB pin. With no external connection, this current pulls FB above the 1 V overvoltage threshold, causing the controller to latch the low-side MOSFET ON and clamp the output voltage near ground-preventing uncontrolled voltage rise and protecting downstream loads.

Is external compensation required for stable operation?

Yes. The COMP pin requires an external RC network (R_F–C_F//C_P) between COMP and FB to stabilize the voltage-mode control loop. Typical values depend on output capacitance and inductance; ST recommends starting with R_F = 10 kΩ, C_F = 1 nF, and C_P = 10 pF, then adjusting based on measured phase margin.