STMicroelectronics L6235QTR

Overview

L6235QTR from STMicroelectronics is a fully integrated DMOS 3-phase brushless DC motor driver with Hall-effect decoding logic, constant t_OFF PWM current control, and non-dissipative overcurrent protection. It operates from 8–52 V supply, delivers 5.6 A peak output current per phase, features 0.3 Ω typical high-side R_DS(on) at 25 °C, supports up to 100 kHz switching frequency, and integrates fast freewheeling diodes - used in industrial BLDC fan drives requiring precise commutation and thermal robustness.

For engineers reviewing the L6235QTR datasheet, L6235QTR pinout, L6235QTR application, or L6235QTR equivalent, key selection considerations include Hall sensor decoding flexibility (60°/120°), synchronous slow-decay recirculation, tacho output for closed-loop speed control, brake function implementation, and QFN48 package thermal performance under continuous 2.5 A DC load.

Technical Context

The L6235QTR implements a 3-phase DMOS bridge with isolated power transistors in BCDmultipower technology, combining CMOS/bipolar logic and high-voltage DMOS on one die. Its Hall decoding logic accepts three single-ended inputs (H1–H3) and autonomously selects between 60° and 120° electrical phasing without external configuration pins.

Current regulation uses a constant t_OFF PWM controller with blanking time (1 µs) to suppress diode reverse-recovery spikes, and recirculation is managed via synchronous rectification during slow-decay mode. Overcurrent detection is non-dissipative and tied to high-side MOSFETs, with diagnostic flag output (DIAG) and thermal shutdown at 165 °C.

Key Specifications

Pinout & Package

Package: QFN48 (7 × 7 mm), exposed thermal pad (EPAD) requiring GND connection for optimal junction-to-board thermal resistance (R_θJB ≈ 5.5 °C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 3-phase BLDC motor driver applications.

Compared with DRV8313PWPR and MP6532GQ-Z, the L6235QTR uniquely integrates Hall decoding, tacho generation, and brake functionality in a single QFN48 package - reducing BOM count by ≥4 ICs and eliminating firmware dependencies for basic BLDC commutation.

Availability

L6235QTR is available at Aetrix Electronics and suitable for industrial fan control, automotive HVAC blowers, medical ventilator motor drives, and robotics joint actuators requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for L6235QTR 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, motor control, and automotive-grade analog/mixed-signal ICs.

The L6235QTR belongs to ST's "Motion Control" product line, designed specifically for cost-sensitive, thermally constrained BLDC applications where integration of gate drive, protection, and Hall decoding reduces system complexity without sacrificing reliability.

FAQ

What is the minimum required external component set to operate the L6235QTR?

The essential external components are: (1) one 0.5–5 mΩ current sense resistor shared between SENSEA and SENSEB; (2) two 220 nF ceramic boot capacitors (one per VBOOT); (3) one 10 nF CP and 100 Ω RP for charge pump; (4) RC network (ROFF/COFF) for t_OFF setting; and (5) pull-up resistors on H1–H3 if open-collector Hall sensors are used. No external gate resistors or freewheeling diodes are needed.

How does the L6235QTR handle motor startup with Hall sensor misalignment?

The L6235QTR's Hall decoding logic accepts all eight possible 3-bit combinations and maps invalid codes (e.g., 000, 111) to safe states - holding outputs off until a valid sequence (e.g., 100 → 110 → 010) is detected. Startup current is limited by the t_OFF-based PWM controller, preventing uncontrolled inrush even with 30° mechanical sensor offset.

Can the L6235QTR drive a sensorless BLDC motor?

No - the L6235QTR requires three active-Hall sensor inputs (H1–H3) for commutation sequencing and has no back-EMF sensing circuitry or zero-crossing detection logic. It is not compatible with sensorless control algorithms; use STSPIN820 or similar for sensorless operation.

What thermal derating applies when operating at 52 V supply with 2.5 A continuous current?

At 52 V and 2.5 A DC, power dissipation is ~1.8 W (based on R_DS(on) = 0.4 Ω avg). With QFN48 mounted on 2-layer 1 oz Cu board (20 cm² copper pour), junction temperature rise is ~35 °C above ambient. Derating begins above 110 °C T_j; full-rated current is maintained up to 85 °C ambient with standard layout - no forced air required.