STMicroelectronics L6228D

Overview

L6228D 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 freewheeling diodes. It operates from 8–52 V supply, delivers 2.8 A peak (1.4 A RMS) output current per bridge, and supports up to 100 kHz switching frequency - used in precision motion control systems requiring compact, thermally robust motor drive solutions.

For engineers reviewing the L6228D datasheet, L6228D pinout, L6228D application, or L6228D equivalent, this page provides verified technical context on its dual-bridge architecture, half/full-step decoding logic, fast/slow decay mode selection, thermal shutdown behavior, and SO24/PowerSO36 package implementation details - all critical for embedded motion control design validation.

Technical Context

The L6228D integrates two independent DMOS full bridges with R_DS(ON) = 0.73 Ω (typ, T_j = 25 °C), each driven by a dedicated constant-off-time PWM current controller using external RC networks (RCA/RCB) to set t_OFF between 6.6 µs and 6 ms. Its phase sequence generator implements full-step (two-phase-on and one-phase-on) and half-step modes via dedicated logic inputs (HALF/FULL, CW/CCW, CLOCK).

It employs non-dissipative overcurrent protection triggered at 2.8 A (typ), cross-conduction prevention via 1 µs deadtime, and quasi-synchronous rectification during fast decay. The charge pump (VCP output, 600 kHz typ) generates V_BOOT to drive high-side N-MOSFETs, while internal blanking (1 µs) suppresses sense comparator false triggering from diode reverse recovery spikes.

Key Specifications

Pinout & Package

Available in SO24 (20 + 2 + 2 lead count) and PowerSO36 packages. Both feature exposed thermal slugs internally connected to multiple GND pins (SO24: pins 6,7,18,19; PowerSO36: pins 1,18,19,36) for enhanced PCB heat 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 L6228D uniquely combines non-dissipative overcurrent protection, on-chip half/full-step sequencing, and dual independent PWM controllers in a single SO24/PowerSO36 package - making it optimal for space-constrained, safety-critical motion systems where reliability and minimal external components are prioritized over ultra-fine microstepping or extreme current headroom.

Availability

L6228D 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 across multi-year production cycles.

Supply support for L6228D 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 medical markets.

The L6228D belongs to ST's high-voltage DMOS stepper driver product line, designed specifically for compact, thermally efficient bipolar stepper motor control in space- and reliability-constrained embedded systems.

FAQ

What is the maximum allowable motor inductance for stable L6228D operation?

The L6228D supports motor inductances from 0.5 mH to over 20 mH, determined by the t_OFF setting range (6.6 µs–6 ms). For a given supply voltage and target current, inductance must satisfy L ≥ (V_S × t_OFF(min)) / I_peak. At 48 V and 2.8 A peak, minimum usable inductance is ~0.11 mH - well below typical stepper values (1.5–10 mH), ensuring robust operation across standard NEMA frame sizes.

How does the L6228D implement non-dissipative overcurrent protection?

It monitors high-side MOSFET conduction via internal current mirrors, triggering a latch that disables the affected bridge without dissipating excess energy in external resistors or Zener clamps. The protection threshold is fixed at 2.8 A (typ), with 100 ns response time and automatic reset after fault clearance - eliminating thermal runaway risk during stall or short-circuit events.

Can the L6228D drive unipolar stepper motors?

No - the L6228D is designed exclusively for two-phase bipolar stepper motors with center-tapped windings not required. Its dual full-bridge topology delivers bidirectional current through each coil pair (A and B), which is incompatible with unipolar motor wiring that relies on single-polarity drive per phase and center-tap switching.

What thermal management is required for continuous 1.4 A RMS operation in SO24 package?

With 1.4 A RMS per bridge and R_DS(ON) = 0.73 Ω, total conduction loss is ~2.8 W. In SO24 on a 6 cm² copper pour (bottom side), R_th-j-amb = 55 °C/W yields ~154 °C rise above ambient - exceeding 150 °C max T_j. A minimum 10 cm² copper area with thermal vias or use of PowerSO36 (R_th-j-case = 2 °C/W) is required for safe continuous operation at rated current.