STMicroelectronics EVAL6474H

Overview

EVAL6474H from STMicroelectronics is an evaluation board designed to demonstrate and validate the L6474 fully integrated microstepping motor driver IC in bipolar stepper motor control applications. It supports 8–45 V motor supply, delivers up to 7.0 A peak (3.0 A r.m.s.) output current, enables 1/16 microstepping via adaptive decay, and features SPI interface, non-dissipative current sensing, and dual-level thermal protection.

For engineers reviewing the EVAL6474H datasheet, EVAL6474H pinout, EVAL6474H application, or EVAL6474H equivalent, this board provides full hardware access to the L6474's registers, real-time current monitoring (ADCIN), configurable slew rate (POW_SR), thermal warning/SD pins (FLAG), and synchronous multi-axis daisy-chaining capability via SYNC.

Technical Context

The EVAL6474H implements the L6474 IC in HTSSOP28 package with dedicated PCB layout optimized for thermal performance: four-layer FR4 board with ~40 cm² copper pour per layer and 15 thermal vias under the IC. It integrates all required passive components-including charge pump capacitors, decoupling networks, and current-sense resistors-for immediate functional validation of the DMOS full-bridge driver.

Board-level design supports both internal oscillator (16 MHz) and external clock input (OSCIN/OSCOUT), configurable deadtime and blanking time (via CONFIG register), and dual-mode overcurrent detection (OCD_TH programmable threshold + hardware fast-trip). The FLAG pin signals thermal warning, overcurrent, UVLO, and standby status in real time.

Key Specifications

Availability

EVAL6474H is available at Aetrix Electronics and suitable for industrial automation, laboratory motion control, and medical device prototyping requiring stable component supply and rapid motor driver validation.

Supply support for EVAL6474H 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, motor control, and embedded processing solutions for industrial, automotive, and consumer applications.

The EVAL6474H belongs to ST's motor control evaluation platform family, engineered to accelerate development of precise, high-current stepper systems using their integrated drivers-emphasizing ease of register configuration, thermal robustness, and system-level fault diagnostics.

FAQ

What motor types does EVAL6474H support?

EVAL6474H is configured exclusively for bipolar stepper motors with two-phase, four-wire topology. It drives each phase through a dedicated DMOS full bridge (OUT1A/OUT2A and OUT1B/OUT2B), supporting phase currents up to 3.0 A r.m.s. It does not support unipolar, servo, or DC brush motors without hardware modification.

Does EVAL6474H include firmware or software tools?

No-EVAL6474H is a hardware-only evaluation board. It requires external host MCU or PC-based SPI controller (e.g., STM32 Nucleo with X-NUCLEO-IHM01A1 expansion) and ST's SPIMaster GUI or custom SPI commands to configure registers like TVAL (torque), STEP_MODE (microstep resolution), and ALARM_EN (protection enable).

Can multiple EVAL6474H boards be synchronized?

Yes-via the SYNC pin, which supports daisy-chain operation. One board acts as master (SYNC output), driving the SYNC input of downstream boards to align step clocks and ensure deterministic multi-axis motion timing without jitter or skew.

Is heatsinking required for continuous 3 A operation?

The EVAL6474H PCB layout includes thermal vias and copper planes sufficient for 3 A r.m.s. at ambient ≤40 °C with natural convection. For sustained >2.5 A or ambient >50 °C, ST recommends adding a low-profile heatsink to the L6474's exposed pad (PGND-connected thermal pad in HTSSOP28).