STMicroelectronics L6235N

Overview

L6235N from STMicroelectronics is a DMOS fully integrated three-phase brushless DC (BLDC) motor driver IC with non-dissipative overcurrent protection, constant t_OFF PWM current control, and 60°/120° Hall-effect decoding logic. It delivers 5.6A peak (2.8A DC) output current per phase, operates from 8–52V supply, features R_DS(ON) = 0.34Ω (typ.) at T_j = 25°C, and supports up to 100kHz switching frequency - enabling precise speed and torque control in compact BLDC motor drives for industrial fans, pumps, and HVAC actuators.

For engineers reviewing the L6235N datasheet, L6235N pinout, L6235N application, or L6235N equivalent, this page provides verified technical context on its Hall decoding flexibility, synchronous rectification timing, thermal shutdown behavior, diagnostic feedback architecture, and bootstrap gate drive implementation - all critical for motor control loop stability and BOM optimization.

Technical Context

The L6235N integrates six DMOS power transistors in a three-phase bridge with cross-conduction protection via 1µs internal dead time, and uses a charge pump (600kHz, 10V V_CP) to sustain high-side gate drive above VS. Its constant t_OFF PWM controller senses current through external shunt resistors connected to SENSEA/SENSEB and compares against VREF (0.1–5V range), with 1µs blanking to suppress diode reverse-recovery spikes.

Hall decoding logic accepts single-ended H1/H2/H3 inputs and auto-distinguishes between 60° and 120° electrical sensor spacing without configuration pins; direction is controlled by FWD/REV logic input, while brake function forces all high-side MOSFETs ON. Diagnostic output (DIAG) signals overcurrent or thermal fault via open-drain pull-down, and TACHO provides frequency-to-voltage conversion synchronized to H1 edges.

Key Specifications

Pinout & Package

Package: PowerDIP24 (20+2+2) - 24-pin dual-in-line package with 20 signal pins + 2 GND pins + 2 heat-dissipating GND pins (pins 1, 18, 19 internally tied to slug). Designed for through-hole mounting with enhanced thermal conduction to PCB copper pour.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STSPIN32F0A and DRV8313, the L6235N offers a complete, cost-optimized analog solution for Hall-sensored BLDC drives below 250W - delivering integrated protection, diagnostics, and timing functions without MCU dependency or external power stage design.

Availability

L6235N is available at Aetrix Electronics and suitable for industrial fan control, automotive HVAC blowers, smart pump drivers, and robot joint actuators requiring stable component supply, long-term lifecycle assurance, and consistent parametric performance across production batches.

Supply support for L6235N 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 specializing in power management, motor control, and embedded processing solutions for industrial, automotive, and consumer markets.

The L6235N belongs to ST's MultiPower-BCD analog power IC product line - designed specifically for highly integrated, thermally efficient motor driver solutions targeting cost-sensitive, high-reliability BLDC applications.

FAQ

What is the minimum recommended value for the RCOFF/COFF network to achieve stable PWM current regulation?

The minimum recommended RCOFF/COFF combination is ROFF = 20kΩ and COFF = 0.47nF, yielding tOFF ≈ 6.6µs. This ensures sufficient off-time for current decay in low-inductance motors while maintaining constant tOFF behavior. Using smaller COFF values risks incomplete capacitor charging before the next monostable trigger, causing variable off-time and current ripple instability.

How does the L6235N implement synchronous rectification during slow-decay mode?

During the tOFF period, after initial high-side turn-off and dead time, the L6235N actively drives the upper MOSFETs as low-impedance switches instead of relying on intrinsic body diodes. This reduces conduction losses by replacing ~1.2V diode drop with <0.3V RDS(ON) × ILOAD, improving efficiency by up to 15% at 2.8A compared to passive freewheeling.

Can the L6235N operate with Hall sensors spaced at 240° or 300° electrical angles?

Yes - the L6235N decodes 240° and 300° Hall configurations by reversing the commutation sequence via the FWD/REV input. The internal logic treats 240° as inverted 120° and 300° as inverted 60°, enabling universal support for all standard BLDC Hall spacings without hardware modification or firmware update.

What thermal derating applies when using the PowerDIP24 package without heatsinking?

In free-air conditions (Rth(j-amb) = 58°C/W), the L6235N's 125°C max junction temperature limits continuous DC output current to ~1.8A per phase at Tamb = 25°C. With 6cm² copper pour (Rth(j-amb) = 43°C/W), it supports full 2.8A DC - confirming that PCB copper area directly governs usable current capacity in this package.