STMicroelectronics TEA3718DP

Overview

TEA3718DP 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 half-step and full-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 industrial motion control systems requiring precise open-loop positioning.

For engineers reviewing the TEA3718DP datasheet, TEA3718DP pinout, TEA3718DP application, or TEA3718DP equivalent, key selection considerations include its 1.5 A continuous output capability, programmable current levels via two logic inputs, monostable pulse timing (toff = 0.69·RT·CT), H-bridge output stage with integrated Darlington transistors and flyback diodes, and alarm-triggered current reduction behavior at junction temperature thresholds.

Technical Context

The TEA3718DP implements a current-regulated chopper drive using three selectable comparator thresholds (VCH = 390 mV, VCM = 230 mV, VCL = 65 mV) controlled by IN0/IN1 logic states, enabling no-current, low-, medium-, and maximum-current modes. Its monostable pulse generator disables the lower power transistors for a fixed off-time (toff) determined by external RC components, allowing precise decay control during current regulation.

The output stage integrates four Darlington transistors and four protection diodes in an H-bridge configuration, with separate VS(A)/VS(B) supply pins for each half-bridge and dedicated SENSE RESISTOR connection for emitter-based current sensing. The ALARM output asserts low when junction temperature reaches T1 ≈ 150 °C, triggering current reduction or shutdown depending on external RC network values.

Key Specifications

Pinout & Package

TEA3718DP uses the Power DIP 12+2+2 package (12 main pins + 2 heat-sink tabs + 2 auxiliary pins), optimized for high-power dissipation in motor drive applications. Thermal resistance R_th(j-c) = 11 °C/W enables reliable operation at 1.5 A with adequate PCB copper area.

Key Features

Applications

Equivalent & Alternatives

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

Compared with L297+L298N and TB6600HG, TEA3718DP offers simpler implementation for single-winding bipolar drive with integrated thermal safety and minimal external parts-ideal for cost-sensitive, space-constrained industrial motion modules where full-step/half-step suffices.

Availability

TEA3718DP is available at Aetrix Electronics and suitable for industrial CNC positioning, printer paper feed mechanisms, HVAC valve actuation, and lab automation sample carousels requiring stable component supply and long-term obsolescence support.

Supply support for TEA3718DP 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, designing and manufacturing analog, mixed-signal, power, and microcontroller products for industrial, automotive, and consumer markets.

The TEA3718DP belongs to ST's legacy motor driver IC family, engineered specifically for robust, cost-effective bipolar stepper motor control in industrial equipment where reliability, thermal resilience, and minimal external component count are prioritized.

FAQ

What is the maximum continuous output current supported by the TEA3718DP?

The TEA3718DP supports ±1.5 A continuous output current per winding, verified under recommended operating conditions (VS = 10–45 V, Tamb = 0–70 °C, with adequate PCB copper area for thermal dissipation). This rating assumes proper heatsinking via the Power DIP 12+2+2 package's thermal tabs and adherence to R_th(j-a) = 45 °C/W limits.

How does the ALARM output function during thermal overload?

The ALARM output goes low when junction temperature reaches approximately 150 °C. This signal can trigger MCU interrupts or external latch circuits. Depending on the RC network connected to the ALARM pin, it may reduce motor current (if RC > 60 Ω) or fully disable the output stage (if RC > 80 Ω), providing scalable thermal response without requiring additional supervision circuitry.

Can the TEA3718DP drive both windings of a bipolar stepper motor?

No-the TEA3718DP controls only one motor winding. A complete two-phase bipolar stepper driver requires two TEA3718DP ICs, one per winding, coordinated via shared PHASE, IN0, and IN1 signals from a microcontroller or LS-TTL source. Each IC manages independent current regulation and thermal monitoring for its respective phase.

What external components are mandatory for basic TEA3718DP operation?

Mandatory components include: (1) a sense resistor (RS) between SENSE RESISTOR pin and GND to set current scale; (2) a reference voltage source (typically 5 V) on REFERENCE pin; (3) RC network on PULSE TIME pin to define off-time; (4) decoupling capacitors on VSS and VS rails; and (5) flyback diodes are already integrated-no external diodes required for standard operation.