STMicroelectronics L6228PDTR

Overview

L6228PDTR from STMicroelectronics is a DMOS dual full-bridge stepper motor driver IC designed for bipolar stepper motor control in industrial motion systems. It delivers 2.8 A peak (1.4 A RMS) output current per bridge, operates from 8–52 V supply, features non-dissipative overcurrent protection, and supports full/half-step excitation with fast/slow decay mode selection.

For engineers reviewing the L6228PDTR datasheet, L6228PDTR pinout, L6228PDTR application, or L6228PDTR equivalent, key selection criteria include its constant t_OFF PWM current control architecture, bootstrap gate drive requirement (V_BOOT), dual independent RC-timed off-time configuration, and thermal shutdown at 165 °C - all critical for precision open-loop stepper positioning in CNC, robotics, and automated instrumentation.

Technical Context

The L6228PDTR integrates two independent DMOS full bridges with R_DS(ON) = 0.73 Ω (typ, T_j = 25 °C), intrinsic fast freewheeling diodes, and cross-conduction protection via 1 µs deadtime. Its phase sequence generator implements full-step (two-phase-on/wave-drive) and half-step modes using CLOCK, CW/CCW, and HALF/FULL logic inputs.

PWM current regulation uses external sense resistors on SENSEA/SENSEB pins, with reference voltages applied to VREFA/VREFB (0–5 V range). Off-time is set by RC networks on RCA/RCB (20–100 kΩ + 0.47–100 nF), yielding t_OFF from 6.6 µs to 6 ms; blanking time (1 µs) suppresses diode reverse-recovery spikes during turn-on.

Key Specifications

Pinout & Package

Available in PowerSO-36 package with exposed thermal slug (internally connected to pins 1, 18, 19, 36 - GND). Pin layout optimized for dual-bridge motor drive with separate power, sense, and control domains.

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 L6228PDTR uniquely combines non-dissipative overcurrent protection, integrated freewheeling diodes, and bootstrap gate drive in a thermally enhanced PowerSO-36 package - making it optimal for industrial stepper systems demanding reliability, efficiency, and simplified layout.

Availability

L6228PDTR is available at Aetrix Electronics and suitable for industrial CNC positioning, medical infusion pumps, automated laboratory analyzers, and 3D printer extruder control requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for L6228PDTR 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, Switzerland, specializing in power management, motion control, and industrial interface ICs.

The L6228PDTR belongs to ST's L62xx family of intelligent motor drivers, engineered specifically for robust, integrated bipolar stepper motor control in harsh industrial and medical environments - emphasizing thermal resilience, fault tolerance, and minimal external component count.

FAQ

What is the minimum recommended external RC network for t_OFF configuration?

The minimum recommended RC values are R_OFF = 20 kΩ and C_OFF = 0.47 nF, yielding t_OFF(MIN) ≈ 6.6 µs. This setting supports high switching frequencies (>50 kHz) and low-inductance motors, but requires careful PCB layout to minimize noise coupling on RCA/RCB pins due to reduced filtering.

How does the L6228PDTR handle motor stall conditions?

During stall, the device triggers non-dissipative overcurrent protection when sensed current exceeds 2.8 A (typ), disabling high-side MOSFETs without external sensing resistors or power-wasting foldback circuits. Thermal shutdown activates at 165 °C if prolonged stall causes excessive junction heating - providing dual-layer fault coverage.

Can the L6228PDTR drive unipolar stepper motors?

No - the L6228PDTR is designed exclusively for two-phase bipolar stepper motors with center-tapped windings. Its dual full-bridge topology requires four-wire (A+, A−, B+, B−) connection and cannot interface with five- or six-wire unipolar configurations that rely on single-ended switching or series/parallel winding reconfiguration.

What is the role of the VCP pin and how is it used?

VCP (Pin 22 / 7) outputs a 600 kHz square wave (10 V amplitude) that drives the external charge pump circuit (C_BOOT, D₁, D₂) to generate V_BOOT. This bootstrap voltage enables gate drive for the high-side N-MOSFETs in both bridges - eliminating need for isolated supplies while maintaining efficient 100% duty-cycle capability for low-speed torque hold.