ST Life.augmented


Stepper Motor Driver for Bipolar Motors with microstepping & programmable current profile
  • active Active

The L9942 is an integrated stepper motor driver for bipolar stepper motors with microstepping and programmable current profile look-up-table to allow a flexible adaptation of the stepper motor characteristics and intended operating conditions. It is possible to use different current profiles depending on target criteria: audible noise, vibrations, rotation speed or torque. The decay mode used in PWM-current control circuit can be programmed to slow-, fast-, mixed-and auto-decay. In autodecay mode device will use slow decay mode if the current for the next step will increase and the fast decay or mixed decay mode if the current will decrease. The programmable stall detection is useful in case of head lamp leveling and bending light application, by preventing to run the motor too long time in stall for position alignment. If a stall is detected, the alignment process is closed and the noise is minimized.

pdf Please read
Errata Sheet
pdf Download

Key Features

  • Two full bridges for max. 1.3 A load(RDSON= 500 mΩ)
  • Programmable current waveform with look-up table: 9 entries with 5 bit resolution
  • Current regulation by integrated PWM controller and internal current sensing
  • Programmable stepping mode: full, half, mini and microstepping
  • Programmable slew rate for EMC and power dissipation optimization
  • Programmable Fast-, Slow-, Mixed- and Auto-Decay Mode
  • Full-scale current programmable with 3 bit resolution
  • Programmable stall detection
  • Step clock input for reduced μController requirements
  • Very low current consumption in standby mode IS< 3 μA, typ. Tj≤ 85 °C
  • All outputs short circuit protected with openload, overload current, temperature warning and thermal shutdown
  • The PWM signal of the internal PWM controller is available as digital output.
  • All parameters are guaranteed for 3 V < Vcc < 5.3 V and for 7 V < Vs < 20 V

Circuit Diagram

Design Resources


Technical Documentation

Product Specifications

Description Version Size
DS4480: Integrated stepper motor driver for bipolar stepper motors with microstepping and programmable current profile
7.0 519 KB

Application Notes

Description Version Size
AN2650: L9942 stepper motor driver for bipolar stepper motors
3.1 642 KB
AN3327: L9942 back EMF stall detection algorithm
3.0 762 KB

User Manual

Description Version Size
UM0839: ST L9942 evaluation board
2.0 817 KB

Related Tools and Software

Related Tools and Software

Part Number Description
EVAL-L9942 Evaluation board for L9942XP microstepping fully integrated motor driver

Publications and Collaterals


Description Version Size
L9942 stepper motor driver
1.0 489 KB
VIPower M0-5: the smart power device
1.0.0 540 KB

Sample & Buy

Part Number Marketing StatusPackagePacking TypeOperating Temperature (min) Operating Temperature (max) Automotive GradeOrder From STUnit Price (US$)*
@ 1000
Distributor AvailabilityRoHS Compliance GradeDownload
Material Declaration**
L9942XP1ActivePowerSSO 24TubeYes-3.18No availability reported, please contact our Sales officeEcopack2PDF
L9942XP1TRActivePowerSSO 24Tape And ReelYesFree Samples3.18Distributor reported inventory date: 2016-02-12
Distributor NameRegionStockMin. order
ARROWOrder NowEUROPE250000

(*) Suggested Resale Price per unit (USD) for BUDGETARY USE ONLY. For quotes, prices in local currency, please contact your local ST Sales Office or our Distributors
(**) The Material Declaration forms available on may be generic documents based on the most commonly used package within a package family. For this reason, they may not be 100% accurate for a specific device. Please contact our sales support for information on specific devices.
Feedback Form
Customer Feedback