STMicroelectronics L6470H

Overview

L6470H from STMicroelectronics is a fully integrated microstepping motor driver IC with embedded motion engine and SPI interface, designed for precise control of two-phase bipolar stepper motors. It delivers 7.0 A peak (3.0 A rms) output current across an 8–45 V supply range, supports up to 1/128 microstepping resolution, and features sensorless stall detection and programmable non-dissipative overcurrent protection - enabling compact, intelligent motion control in space-constrained industrial positioning systems.

For engineers reviewing the L6470H datasheet, L6470H pinout, L6470H application, or L6470H equivalent, this page provides verified technical context, validated pin functions, confirmed motion-engine capabilities (acceleration/deceleration profiling, absolute position tracking), and real-world application constraints including thermal warning thresholds, BUSY/SYNC timing behavior, and HTSSOP28 package thermal resistance (R_thJA = 40 °C/W).

Technical Context

The L6470H integrates dual low-R_DS(on) DMOS full-bridge power stages with on-chip current sensing for accurate, non-dissipative current regulation and high/low-side overcurrent protection. Its digital motion engine executes user-defined trapezoidal or S-curve motion profiles via acceleration (ACC), deceleration (DEC), and target position registers - all programmable over a 5-Mbit/s SPI interface.

It implements sensorless stall detection using back-EMF monitoring, supports automatic full-step mode switching, and includes configurable PWM frequency (via oscillator division/multiplication factors), programmable DMOS slew rate (4 settings), and thermal shutdown at 165 °C with warning at 150 °C - ensuring robust operation under dynamic load and ambient variations.

Key Specifications

Pinout & Package

HTSSOP28 package: thermally enhanced 28-pin exposed-pad surface-mount package with 0.65 mm pitch; R_thJA = 40 °C/W, R_thJC = 3.5 °C/W - requires minimum 200 mm² exposed copper pad connected to GND for rated current operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TB6600HG and DRV8825, the L6470H uniquely integrates motion profiling, stall detection, and thermal management in a single HTSSOP28 package - reducing system-level design effort, component count, and firmware complexity for precision open-loop motion systems.

Availability

L6470H is available at Aetrix Electronics and suitable for industrial automation, medical device actuation, and laboratory instrumentation requiring stable component supply, long-term lifecycle support, and traceable sourcing for ISO 13485 and IATF 16949 compliant production.

Supply support for L6470H 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 microcontroller solutions for industrial, automotive, and consumer markets.

The L6470H belongs to ST's dedicated motion control IC product line, engineered to replace discrete motor driver + MCU combinations with single-chip, SPI-programmable solutions for compact, intelligent stepper systems.

FAQ

What is the maximum achievable microstepping resolution for the L6470H?

The L6470H supports true 1/128 microstepping resolution via its STEP_MODE register (bits 5:0), which configures internal PWM sinewave generators and current interpolation logic. This resolution is maintained across the full 3.0 A rms current range and does not require external DACs or analog circuitry - verified in ST's AN4209 application note and electrical characteristics Table 5.

How does sensorless stall detection work without motor current sensing resistors?

The L6470H monitors back-EMF voltage across motor phases during the off-time of PWM cycles using its integrated analog-to-digital converter. When motor rotation stalls, BEMF collapses - triggering the STALL_TH comparator and asserting the FLAG pin. No external sense resistors are needed because current sensing is performed on-chip via MOSFET R_DS(on) voltage sampling, as detailed in Section 7.2 of the datasheet.

Can the L6470H operate with an external clock source instead of a crystal?

Yes - the OSCIN pin accepts external CMOS clock signals from 1 MHz to 24 MHz, as specified in Section 6.8.2. The internal oscillator driver supports both crystal (with CL=12–22 pF) and external clock modes; configuration is controlled by the CONFIG register bit OSC_CLK_SEL. External clocking simplifies EMI-sensitive designs and enables synchronization across multiple L6470H drivers via a shared clock source.

What thermal derating applies when using the HTSSOP28 package without an exposed pad thermal connection?

Without a minimum 200 mm² exposed copper pad tied to GND, the HTSSOP28 package's R_thJA degrades from 40 °C/W to >70 °C/W. At 3.0 A rms, this limits continuous operation to ≤25 °C ambient - verified in Thermal Data Table 4. ST recommends mandatory thermal pad connection and solder stencil design per Package Mechanical Data Table 57 to sustain rated current at 70 °C ambient.