STMicroelectronics TEA3718SDP

Overview

TEA3718SDP from STMicroelectronics is a bipolar stepper motor driver IC designed to regulate constant current in one winding of a bipolar stepper motor using switch-mode chopper control. It supports full-step and half-step modes, delivers up to 1.5 A output current, operates from 10–45 V motor supply (VS), features built-in protection diodes, thermal overload protection with ALARM output, and accepts LS-TTL-compatible logic inputs (IN0, IN1, PHASE). It is used in open-loop motion control for industrial automation actuators.

For engineers reviewing the TEA3718SDP datasheet, TEA3718SDP pinout, TEA3718SDP application, or TEA3718SDP equivalent, key selection considerations include its 1.5 A continuous output capability, integrated H-bridge output stage with Darlington transistors and clamping diodes, programmable current levels via two logic inputs, thermal alarm behavior at junction temperature ≥150 °C, and compatibility with unstabilized motor supplies in Power DIP 12+2+2 packaging.

Technical Context

The TEA3718SDP implements a current-regulated chopper drive using a monostable pulse generator triggered by comparator outputs. Three selectable current thresholds (no current, low, medium, max) are set via IN0/IN1 logic states and a reference voltage applied to REFERENCE, with sensing performed across an external SENSE RESISTOR. The output stage is a four-transistor H-bridge with integrated protection diodes.

Phase direction is controlled by the PHASE input, which passes through a Schmitt trigger and delay circuit to prevent shoot-through during polarity reversal. The ALARM output goes low when junction temperature reaches ~150 °C, initiating current reduction or shutdown depending on RC network configuration at the ALARM pin - a feature specific to TEA3718SDP, TEA3718SP, and TEA3718DP variants.

Key Specifications

Pinout & Package

TEA3718SDP uses the Power DIP 12+2+2 package (12 main pins + 2 VS(A) + 2 VS(B)), optimized for high-current motor drive with enhanced thermal conduction through extended leadframe tabs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bipolar stepper motor driver applications.

Compared with L298N and TB6600HG, TEA3718SDP offers the lowest component count for basic bipolar chopper drive, integrates all protection functions in a thermally robust Power DIP package, and delivers deterministic current regulation without microcontroller intervention - ideal for cost-sensitive, thermally constrained industrial motion nodes.

Availability

TEA3718SDP is available at Aetrix Electronics and suitable for industrial CNC axis drivers, printer paper feed mechanisms, valve actuator positioners, and lab equipment sample carousels requiring stable component supply and long-term obsolescence management.

Supply support for TEA3718SDP 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 automotive-grade ICs with strong industrial market focus.

The TEA3718 series belongs to ST's dedicated stepper motor driver product line, engineered for robust open-loop motion control in harsh environments where reliability, thermal resilience, and minimal external components are essential.

FAQ

What is the maximum allowable motor supply voltage for TEA3718SDP?

The absolute maximum VS rating is 50 V, but the recommended operating range is 10–45 V per datasheet Table 5. Operation above 45 V risks exceeding safe junction temperature under full load due to increased power dissipation in the Darlington output stage and reduced thermal headroom in the Power DIP package.

Can TEA3718SDP drive a unipolar stepper motor?

No - TEA3718SDP is strictly a bipolar driver requiring two leads per winding and H-bridge switching. It cannot energize center-tapped unipolar windings or perform phase sequencing for unipolar configurations. Its architecture assumes bidirectional current flow through a single winding.

How does the ALARM output behave during thermal overload?

When junction temperature reaches ~150 °C, the ALARM pin pulls low (open-collector). If an external RC network is connected, current is reduced per the formula Im = VTH × RS / (R + RC); with RC > 80 Ω, the output stage disables completely. No internal latching occurs - recovery is automatic upon cooling.

Is a heatsink required for continuous 1.5 A operation?

A dedicated heatsink is not required if the PCB provides ≥4 cm² of 35 µm copper connected to GND and VS pins. With that layout, thermal resistance drops to Rth(j-a) ≈ 45 °C/W, allowing 1.5 A at Tamb = 70 °C without exceeding TJ(max) = 150 °C. Forced air or heatsink further extends margin.