STMicroelectronics L6258EX

Overview

L6258EX from STMicroelectronics is a dual full-bridge DMOS motor driver IC designed for bipolar stepper and dual DC motor control, featuring 1.5A continuous output current per bridge, 12–40V supply range, four-quadrant PWM current control, and integrated recirculation diodes. It enables microstepping via precision DAC-based current regulation and supports TTL/CMOS logic inputs with cross-conduction protection.

For engineers reviewing the L6258EX datasheet, L6258EX pinout, L6258EX application, or L6258EX equivalent, this device is selected for high-efficiency, thermally robust motor drive in industrial automation, CNC positioning systems, and precision motion control where low-current-ripple chopping and bidirectional torque control are required.

Technical Context

The L6258EX implements two independent PWM current control loops using transconductance amplifiers, each comparing a DAC-programmed reference voltage against a sense-resistor feedback signal. Chopping frequency (up to 37 kHz) is set by an external capacitor on the TRI_CAP pin, and phase-shifted triangular waveforms (TRI_0/TRI_180) drive comparators to generate complementary PWM outputs.

Its BCD process power stage integrates high-side and low-side DMOS transistors with bootstrap gate driving (VBOOT up to 60V), enabling full-bridge operation without external flyback diodes. Thermal shutdown activates at 150°C with 25°C hysteresis, and disable functionality halts both bridges independently of logic state.

Key Specifications

Pinout & Package

Package: PowerSO-36 - thermally enhanced exposed-pad surface-mount package with 4 internal PWR_GND pins (1, 18, 19, 36) for direct die-to-PCB heat transfer and low-inductance grounding.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual full-bridge motor driver applications.

Compared with TB6600HG and DRV8825, the L6258EX uniquely combines integrated diodes, programmable microstepping via DAC, and 40V operation in a thermally optimized package - making it optimal for industrial-grade, low-noise, dual-motor systems where BOM reduction and thermal reliability are prioritized over raw peak current.

Availability

L6258EX is available at Aetrix Electronics and suitable for industrial CNC positioning, medical infusion pump drive, automated laboratory stage, and printed circuit board router applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for L6258EX 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 automotive-grade ICs, with manufacturing facilities certified to ISO 9001 and IATF 16949 standards.

The L6258EX belongs to ST's "Motor Control & Power" product line, engineered specifically for high-efficiency, thermally resilient motor drive in industrial automation and precision instrumentation where reliability under continuous load is non-negotiable.

FAQ

What is the minimum sense resistor value recommended for L6258EX at 1.5A continuous output?

The L6258EX senses current via a differential voltage across an external sense resistor (Rs), with full-scale sense voltage fixed at 1.25V. To achieve 1.5A continuous current, Rs must be ≤0.83Ω (1.25V ÷ 1.5A). ST recommends 0.5Ω metal-film resistors for optimal accuracy and thermal stability, yielding 0.75V drop at 1.5A and sufficient headroom below the 1.25V limit.

Can L6258EX operate without external charge pump capacitors?

No. The L6258EX requires two external capacitors: a 10nF pump capacitor (CP) between VCP1 and VCP2, and a 100nF storage capacitor (Cboot) between VBOOT and VS. These are mandatory for generating the boosted gate voltage needed to fully enhance the high-side DMOS transistors. Omitting either capacitor results in incomplete high-side turn-on, excessive conduction loss, and potential thermal shutdown.

How does the PH input interact with the I0–I3 DAC inputs during microstepping?

The PH input sets winding current direction (positive/negative), while I0–I3 select the magnitude percentage (0–100%) of full-scale current defined by VREF and Rs. During microstepping, PH toggles per step to reverse polarity, and I0–I3 are sequenced to ramp current magnitude smoothly between steps - e.g., PH high + I0–I3 = 0001 (9.5%) → PH high + 0010 (19.1%) → PH low + 0001 (9.5%), etc., forming sinusoidal current waveforms.

Is L6258EX compatible with 3.3V logic controllers?

Yes, but with caution. While the L6258EX inputs are TTL/CMOS compatible and accept logic-high down to 2.0V (V_IN(H) min), 3.3V microcontrollers must ensure clean, noise-immune signal routing. For robust operation, use series 100Ω resistors and local 0.1μF decoupling at each input pin. Avoid direct connection without impedance matching if the MCU has weak drive strength or operates near 3.3V VDD tolerance limits.