STMicroelectronics EVAL6474PD

Overview

EVAL6474PD from STMicroelectronics is a fully functional evaluation board for the L6474 POWERSO36-packaged microstepping motor driver IC, designed to validate bipolar stepper motor control up to 45 V and 7.0 A peak current. It implements adaptive decay current control, SPI-configurable 1/16 microstepping, non-dissipative overcurrent protection, and dual-level thermal shutdown - enabling rapid prototyping of precision motion systems in industrial automation and medical devices.

For engineers reviewing the EVAL6474PD datasheet, EVAL6474PD pinout, EVAL6474PD application, or EVAL6474PD equivalent, this board provides verified hardware reference for L6474PD integration, SPI register configuration (e.g., STEP_MODE, OCD_TH, TVAL), thermal management validation on four-layer FR4 with 22 thermal vias, and real-world assessment of adaptive decay performance under dynamic load conditions.

Technical Context

The EVAL6474PD implements the full signal chain of the L6474PD IC: motor supply (8–45 V) routed through POWERSO36 power terminals, logic-level SPI interface (SCK, SDI, SDO, SYNC, CS) connected to standard headers, and integrated charge pump driving high-side MOSFETs. All protections - UVLO (7.2 V turn-on), thermal warning (130 °C), shutdown (160 °C), and per-bridge non-dissipative overcurrent detection - are electrically validated on-board.

It supports both internal oscillator (16 MHz) and external clock input via OSCIN/OSCOUT pins, enables daisy-chained SPI configuration across multiple drivers, and exposes all critical analog monitoring points: ADCIN for external torque regulation, FLAG for alarm status, and STBY/RESET for system-level control sequencing.

Key Specifications

Availability

EVAL6474PD is available at Aetrix Electronics and suitable for industrial CNC positioning, laboratory automation instrumentation, and medical infusion pump development requiring stable component supply and pre-validated motor control reference designs.

Supply support for EVAL6474PD 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, delivering automotive-grade, industrial, and power management solutions with vertical manufacturing and broad IP portfolio.

The EVAL6474PD belongs to ST's dedicated motor control evaluation platform family, engineered to accelerate adoption of intelligent, SPI-programmable stepper drivers in space-constrained, thermally demanding applications.

FAQ

What motor types and voltage levels does EVAL6474PD support?

EVAL6474PD is configured for bipolar stepper motors only, with motor supply voltage range of 8–45 V DC. It supports rated continuous current up to 3.0 A RMS (7.0 A peak) and requires external power supply decoupling per ST's layout guidelines. The board does not support unipolar or servo motor topologies.

How is SPI communication implemented on EVAL6474PD?

EVAL6474PD exposes the full L6474PD SPI interface: SCK, SDI, SDO, CS, and SYNC pins on 0.1″ headers. It operates at up to 5 Mbit/s with standard mode timing, supports daisy-chaining via SDO-to-SDI routing, and includes pull-up resistors on CS and SYNC for robust initialization. No firmware or bootloader is embedded - host MCU handles all register writes.

Does EVAL6474PD include thermal measurement capability?

Yes - EVAL6474PD integrates the L6474PD's on-die temperature sensor, with thermal warning (130 °C) and shutdown (160 °C) thresholds directly accessible via STATUS register bits. The board's PCB layout uses 22 thermal vias beneath the POWERSO36 footprint and 40 cm² copper pour per layer to replicate production thermal resistance (R_thJA = 12 °C/W).

Can EVAL6474PD be used for closed-loop current control verification?

Yes - EVAL6474PD enables full validation of the L6474PD's non-dissipative current sensing architecture. The TVAL register sets peak current amplitude, while adaptive decay mode (controlled by STEP_MODE and ALARM_EN) dynamically adjusts off-time to maintain precise current waveform fidelity - measurable via OUTA/OUTB differential probes and confirmed using the ADC_OUT register readback.