AMIS30623C623BRG Datasheet, PDF (23/61 Pages) ON Semiconductor – Micro-stepping Motor Driver

T shutdown level
T
T warning level
AMIS−30623
t
T <tw> bit
T <tsd> bit
T < T_tw and
getstatus or
getfullstatus
T > Ttsd, motor
stops and
shutdown
T < T_tw and
getstatus or
getfullstatus
Figure 15. Illustration of Thermal Management Situation
Autarkic Functionality in Under−Voltage
Condition
Battery Voltage Management
The AMIS−30623 monitors the battery voltage by means
of one threshold and one shutdown level. The only condition
to reset flags <UV2> and <StepLoss> is to recover by a
battery voltage higher than UV1 and to receive a
GetStatus or a GetFullStatus command.
Autarkic Function
The device enters states <HardUnder> (see Figure 16),
followed by <ShutUnder> when V_BB is below the UV2
level or <CPFail> = 1. The motion is stopped immediately
and Target Position (TagPos) is kept and not overwritten by
Actual Position (ActPos). The motor is in HiZ state and the
flags <UV2> and <Steploss> are set to inform the master
that the voltage has dropped below UV2 or the charge pump
voltage has dropped below the level of the charge pump
comparator and loss of steps is possible.
• If in this state V_BB becomes > UV1 within 15 seconds,
then AMIS−30623 returns to <Stopped> state. From
there, it resumes the interrupted motion and accepts
updates of the target position by means of the
commands SetPosition, SetPositionShort,
SetPosParam and GotoSecurePosition, even
if the <UV2> flag, the <CPFail> flag and
<Steploss> flags are NOT cleared.
• If however the V_BB voltage remains below UV2 level
or the charge pump voltage level is below the charge
pump comparator for more than 15 seconds, then the
device will enter <Shutdown> state and the target
position is overwritten by Actual Position. This state
can be exited only if V_BB is > UV1, the charge pump
voltage is above the charge pump comparator voltage
and an incoming command GetStatus or
GetFullStatus is received.
Important Notes:
1. In the case of Autarkic positioning, care needs to
be taken because accumulated steploss can cause a
significant deviation between physical and stored
actual position.
2. The SetDualPosition command will only be
executed after clearing the <UV2>, CPFail and
<Steploss> flags.
3. RAM reset occurs when Vdd < VddReset (digital
Power−On−Reset level).
4. The Autarkic function remains active as long as
V_DD > VddReset.
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