AMIS-30622_13 Datasheet, PDF (15/50 Pages) ON Semiconductor – I2C Micro-Stepping Motor Driver

AMIS−30622
reporting of an electrical problem that could occur on the
coils or the charge pump.
Control Logic (Position Controller and Main Control)
The control logic block stores the information provided by
the I²C interface (in a RAM or an OTP memory) and
digitally controls the positioning of the stepper motor in
terms of speed and acceleration, by feeding the right signals
to the motordriver state machine.
It will take into account the successive positioning
commands to properly initiate or stop the stepper motor in
order to reach the set point in a minimum time.
It also receives feedback from the motordriver part in
order to manage possible problems and decide on internal
actions and reporting to the I²C interface.
Miscellaneous
The AMIS−30622 also contains the following:
• An internal oscillator, needed for the control logic
handler as well as the control logic and the PWM
control of the motordriver.
• An internal trimmed voltage source for precise
referencing.
• A protection block featuring a thermal shutdown and a
power−on−reset circuit.
• A 5 V regulator (from the battery supply) to supply the
internal logic circuitry.
FUNCTIONS DESCRIPTION
This chapter describes the following functional blocks in Position Controller
more detail:
• Position controller
• Main control and register, OTP memory + ROM
• Motordriver
Positioning and Motion Control
A positioning command will produce a motion as
illustrated in Figure 7. A motion starts with an acceleration
phase from minimum velocity (Vmin) to maximum velocity
(Vmax) and ends with a symmetrical deceleration. This is
defined by the control logic according to the position
required by the application and the parameters programmed
Ì _Acceleration
Ì ^range
ÌÌ _{Zero Speed}
Hold Current
ÌÌÌÌÌÌ _Pstart
Pmin
by the application during the configuration phase. The
current in the coils is also programmable.
ÌÌÌÌ _Velocity
Deceleration
range
ÌÌÌÌ _Vmax
Zero Speed
Hold Current
ÌÌÌÌ _Vmin
ÌÌÌÌÌÌÌÌ _P=0
Pstop
Position
Pmax
Figure 7. Positioning and Motion Control
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