STMicroelectronics L6208PD

Overview

L6208PD from STMicroelectronics is a DMOS dual full-bridge stepper motor driver IC designed for bipolar stepper motor control in industrial motion systems. It delivers 5.6 A peak (2.8 A RMS) output current per bridge, operates from 8–52 V supply, features non-dissipative overcurrent protection, and supports full/half-step sequencing with fast/slow decay modes - used in CNC positioning stages requiring precise microstepping-capable current regulation.

For engineers reviewing the L6208PD datasheet, L6208PD pinout, L6208PD application, or L6208PD equivalent, key selection criteria include its 100 kHz switching frequency, R_DS(ON) = 0.34 Ω (typ, T_j = 25 °C), integrated charge pump (VCP output), dual independent PWM current controllers, and PowerSO36 thermal performance (R_th-j-case = 1 °C/W).

Technical Context

The L6208PD integrates two independent DMOS full bridges with intrinsic fast freewheeling diodes and cross-conduction protection via 1 µs internal deadtime. Each bridge uses constant t_OFF PWM current control with external RC timing networks (RCA/RCB) and analog reference inputs (VREFA/VREFB) to regulate phase current by sensing voltage across external sense resistors.

It embeds a dedicated phase sequence generator for full-step (two-phase-on/wave-drive) and half-step operation, driven by TTL/CMOS-compatible logic inputs (CLOCK, CW/CCW, HALF/FULL). The charge pump (VCP oscillator at 600 kHz typ.) generates VBOOT to drive high-side N-MOSFETs, enabling efficient operation up to 52 V without external high-voltage gate drivers.

Key Specifications

Pinout & Package

Available in PowerSO36 package with exposed thermal slug (internally connected to pins 1, 18, 19, 36), optimized for high-power motor drive applications requiring low junction-to-case thermal resistance (1 °C/W).

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 L6208PD uniquely combines 5.6 A peak current, integrated charge pump, non-dissipative OCP, and programmable decay modes in a single PowerSO36 package - making it optimal for compact, thermally constrained industrial motion controllers requiring robust fault handling.

Availability

L6208PD is available at Aetrix Electronics and suitable for industrial CNC positioning, automated laboratory equipment, PCB drilling systems, and medical infusion pump actuation requiring stable component supply across multi-year production cycles.

Supply support for L6208PD 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 L6208PD belongs to ST's L62xx family of intelligent motor drivers, engineered specifically for high-current bipolar stepper applications demanding integrated protection, thermal resilience, and minimal external component count in industrial automation.

FAQ

What is the maximum allowable motor supply voltage for L6208PD?

The absolute maximum supply voltage is 60 V, but the recommended operating range is 8–52 V per the datasheet. Operation above 52 V risks exceeding safe operating area limits for the internal DMOS transistors, especially under transient conditions or elevated junction temperature. At 52 V, R_DS(ON) increases by ~15% versus 25 °C rating, requiring derating of continuous current to maintain thermal safety.

How does the non-dissipative overcurrent protection work without external components?

The L6208PD senses current via the voltage drop across the external sense resistor connected to SENSEA/SENSEB. When this voltage exceeds VREFA/VREFB, the internal comparator triggers an immediate, cycle-by-cycle shutdown of the affected bridge's power MOSFETs - without dissipating excess energy in external shunts or comparators. The EN pin reflects this fault state, allowing host MCU to detect and respond.

Can L6208PD drive unipolar stepper motors?

No - the L6208PD is designed exclusively for two-phase bipolar stepper motors with center-tapped windings not required. Its dual full-bridge topology applies bidirectional voltage to each phase, enabling full/half-step excitation. Unipolar motors require separate transistor arrays per phase and lack the current reversal capability needed for torque generation in this architecture.

What thermal interface is required for PowerSO36 mounting?

The PowerSO36 package requires soldering the exposed thermal slug (pins 1/18/19/36) to a minimum 6 cm² copper pour on the PCB's bottom layer, with ≥16 thermal vias (0.3 mm diameter) connecting to an internal ground plane. This achieves R_th-j-amb = 15 °C/W, enabling 5.6 A peak current operation at T_amb ≤ 70 °C without external heatsink.