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September 2013 Doc ID 11778 Rev 7 1/40
1
L9942
Integrated stepper motor driver for bipolar stepper motors
with microstepping and programmable current profile
Features
■ Two full bridges for max. 1.3 A load
(R
DSON
= 500 m)
■ 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
I
S
< 3 µA, typ. T
j
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
Applications
Stepper motor driver for bipolar stepper motors in
automotive applications like light levelling,
Bending light and Throttle control.
Description
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.
PowerSSO24
Table 1. Device summary
Order code Junction temp. range, CPackage Packing
L9942XP1 -40 to 150 PowerSSO24 Tube
L9942XP1TR -40 to 150 PowerSSO24 Tape and reel
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