STMicroelectronics L6208Q

Overview

L6208Q from STMicroelectronics is a fully integrated DMOS dual full-bridge stepper motor driver for bipolar stepper motors, featuring non-dissipative overcurrent protection, dual independent constant t_OFF PWM current controllers, and built-in fast/slow decay synchronous rectification. It operates from 8–52 V supply, delivers up to 5.6 A peak output current per bridge, and supports up to 100 kHz switching frequency - enabling precise microstepping control in industrial motion systems.

For engineers reviewing the L6208Q datasheet, L6208Q pinout, L6208Q application, or L6208Q equivalent, this device is selected for high-current bipolar stepper drive where thermal robustness, integrated freewheeling diodes, and programmable current regulation via external RC networks are required - especially in closed-loop positioning, CNC axes, and automated valve actuation.

Technical Context

The L6208Q integrates two independent DMOS full bridges with R_DS(on) = 0.34 Ω (typ) at T_j = 25 °C, each controlled by a dedicated constant-off-time PWM current regulator using external RC timing networks on RCA/RCB pins. Its phase sequence generator handles full-step (two-phase-on and one-phase-on) and half-step modes via dedicated logic inputs (HALF/FULL, CW/CCW, CLOCK).

It implements cross-conduction protection with 1 µs internal deadtime, non-dissipative overcurrent detection triggering shutdown at 5.6 A (typ), and thermal shutdown at 165 °C. The charge pump (VCP output, 600 kHz typ) enables N-channel high-side drive, and integrated fast freewheeling diodes eliminate need for external catch diodes.

Key Specifications

Pinout & Package

Package: VFQFPN48 (7 × 7 × 1.0 mm), thermally enhanced with exposed EPAD connected to GND for improved power dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bipolar stepper motor driver applications.

Compared with TB6600HG and DRV8825, the L6208Q uniquely combines 5.6 A peak drive, 52 V operation, non-dissipative OCP, and integrated diodes - making it the only option among the three qualified for continuous-duty 48 V industrial stepper applications with minimal external components.

Availability

L6208Q is available at Aetrix Electronics and suitable for industrial CNC axis drive, automated fluid control valve, medical infusion pump actuator, and lab automation sample carousel requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for L6208Q 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, motion control, and automotive-grade ICs with vertical manufacturing capability.

The L6208Q belongs to ST's "Motor Control & Power" product line, engineered specifically for high-reliability, high-current stepper motor drive in industrial automation and precision motion systems - emphasizing thermal resilience, integration density, and functional safety readiness.

FAQ

What is the minimum external sense resistor value supported for 5.6 A peak current?

The L6208Q's current sense comparator has ±5 mV offset. To maintain ≤1% current error at 5.6 A, the sense resistor must generate ≥56 mV at peak - requiring R_SENSE ≥ 0.01 Ω. ST recommends 0.01 Ω ±1% metal foil resistors with 2 W derating for continuous operation.

Can the L6208Q drive unipolar stepper motors?

No - the L6208Q is designed exclusively for two-phase bipolar stepper motors with center-tapped windings unsupported. Its dual full-bridge topology requires four-wire (A+, A−, B+, B−) connection and cannot configure phases as unipolar taps.

How is thermal performance affected by EPAD soldering quality?

Thermal resistance R_θJA drops from 45 °C/W (reflow only) to 28 °C/W when the EPAD is fully soldered to a 4-layer PCB with ≥4 thermal vias (0.3 mm diameter, filled). Inadequate EPAD connection increases junction temperature by >35 °C at 3 A RMS, risking premature thermal shutdown.

Does the charge pump require specific capacitor ESR limits?

Yes - the CP capacitor (10 nF) must have ESR < 2 Ω at 600 kHz. Ceramic C0G/NP0 types are mandatory; X7R ceramics introduce excessive loss and voltage droop, degrading VBOOT stability and causing high-side drive failure above 30 V supply.