STMicroelectronics L6226QTR

Overview

L6226QTR from STMicroelectronics is a DMOS dual full-bridge motor driver IC designed for bipolar stepper and dual/quad DC motor control, featuring 8–52 V supply range, 2.8 A peak output current per bridge, 0.73 Ω typical R_DS(on) at 25 °C, programmable high-side overcurrent detection, and integrated fast freewheeling diodes. It operates up to 100 kHz switching frequency and delivers real-time diagnostic feedback via open-drain OCDA/OCDB pins.

For engineers reviewing the L6226QTR datasheet, L6226QTR pinout, L6226QTR application, or L6226QTR equivalent, this device supports precise current-limited motor actuation in space-constrained industrial motion systems where thermal shutdown, cross-conduction protection, and bootstrap charge-pump gate drive are critical design requirements.

Technical Context

The L6226QTR integrates two independent full-bridge power stages using BCDmultipower technology, combining isolated DMOS transistors with CMOS/bipolar logic on a single die. Each bridge includes non-dissipative high-side current sensing, dead-time-controlled gate drivers (1 µs typical), and internal 600 kHz charge pump oscillator (VCP output) for N-channel high-side MOSFET drive.

Logic inputs (IN1A/IN2A/IN1B/IN2B, ENA/ENB) are TTL/CMOS compatible with 1.8 V turn-on and 1.3 V turn-off thresholds and 0.5 V hysteresis. Overcurrent detection thresholds are set by external resistors (PROGCLA/PROGCLB) and yield ±10% accuracy across –25 to +125 °C when using 5–40 kΩ programming resistors.

Key Specifications

Pinout & Package

Package: QFN32 (5 × 5 mm, 0.5 mm pitch), thermally enhanced with exposed die pad connected to GND (pins 2–8 internally tied to die PAD).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual full-bridge motor driver applications.

Compared with TB6600HG and DRV8876PWPR, the L6226QTR uniquely combines dual-bridge integration, wide 8–52 V operation, resistor-programmable OCD, and diagnostic outputs in a single QFN32 package-making it optimal for space- and thermal-constrained industrial motion systems requiring analog configurability and hardware fault resilience.

Availability

L6226QTR is available at Aetrix Electronics and suitable for industrial motion control, automated test equipment, and embedded robotics requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for L6226QTR 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, motion control, and embedded processing solutions for industrial, automotive, and consumer markets.

The L6226QTR belongs to ST's high-voltage motor driver product line, engineered specifically for robust, thermally efficient full-bridge control of stepper and DC motors in harsh industrial environments.

FAQ

What is the minimum recommended bootstrap capacitor value for stable VBOOT operation?

The datasheet specifies C_BOOT = 220 nF as the standard value for reliable high-side gate drive across the full 8–52 V supply range and 100 kHz switching. Using <100 nF risks insufficient charge hold-up during high-duty-cycle operation, leading to high-side FET dropout and increased R_DS(on) heating. Ceramic X7R dielectric is required for low ESR and stable capacitance over temperature.

How does the L6226QTR handle simultaneous overcurrent events on both bridges?

Each bridge has independent OCD circuits feeding OCDA and OCDB pins. If both detect overcurrent, both open-drain outputs pull low simultaneously. When ENA and ENB are tied to their respective OCD pins (standard configuration), both bridges disable within <200 ns of the first fault, ensuring coordinated shutdown without race conditions or partial activation.

Can unused logic inputs (e.g., IN2B) be left floating?

No - all logic inputs must be actively driven to valid TTL/CMOS levels. Floating inputs risk metastability, unintended bridge activation, or increased EMI susceptibility. The datasheet explicitly recommends tying unused IN/EN pins to either GND (low) or 5 V (high) via ≤10 kΩ resistors to ensure deterministic state and noise immunity.

What is the thermal resistance impact of connecting NC pins to GND?

Pins 2–8 are internally connected to the exposed die pad. Connecting them to a large GND copper pour (≥6 cm² with ≥18 thermal vias) reduces R_th(JA) from 42 °C/W to ~28 °C/W per the thermal characterization data. This 33% improvement enables 1.4 A RMS operation at +85 °C ambient without derating, versus forced-air cooling requirements for unconnected pads.