AMIS-30623 Datasheet, PDF (24/65 Pages) AMI SEMICONDUCTOR – LIN Microstepping Motordriver

AMIS-30623
14.2.7. Autarkic Functionality in Under-voltage Condition
14.2.7.1. Battery Voltage Management
The AMIS-30623 monitors the battery voltage by means of one threshold and one shutdown level, as illustrated in the state diagram
below. The only condition to reset flags <UV2> and <StepLoss> is to recover a battery voltage higher than UV1 and to receive a
GetStatus or a GetFullStatus command.
Normal voltage
- <UV2 > = ‘0’
- <StepLoss > = ‘0’
Vbb > UV1 &
LIN frame:
GetStatus or
GetFullStatus
Vbb < UV2
(no motion)
Stop mode 1
- <UV2 > = ‘ 1’
- <StepLoss > = ‘0’
- Motor shutdown
(motion disabled)
Vbb < UV2 &
motion ongoin g
Stop mode 2
- <UV2 > = ‘ 1’
- <StepLoss > = ‘ 1’
- HardStop
- Motor shutdown
(motion disabled)
Figure 17: State Diagram Battery Voltage Management
14.2.7.2. Autarkic Function
In Stop mode 1 the motor is put in shutdown state. The <UV2> flag is set. In case Vbb > UV1 AMIS-30623 accepts updates of the
target position by means of the reception of SetPosition, SetPositionShort, SetPosParam and GotoSecurePosition
commands, even if the <UV2> flag is NOT prior cleared.
In Stop mode 2 the motor is stopped immediately and put in shutdown state. The <UV2> and <Steploss> flags are set. In case Vbb
> UV1 AMIS-30623 autonomously resumes the motion to the original target position using the stored motor parameters (minimum and
maximum velocity, acceleration, step-mode, run- and hold current) in case no RAM reset occurred. The flags are only cleared after
receiving a GetStatus or GetFullStatus command. Updates of the target position by means of the reception of SetPosition,
SetPositionShort, SetPosParam and GotoSecurePosition commands is accepted, even if the <UV2> and <Steploss> flags
are NOT prior cleared.
Important notes:
1. In the case of Stop mode 2 care needs to be taken because the 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> and <Steploss> flags.
3. RAM reset occurs when Vdd < VddReset (digital Power On Reset level)
4. The Autarkic function remains active as long as Vdd > VddReset
14.2.7.3. Logical Implementation Autarkic Function
The logic uses the <UV2>, <CPFail> and <Steploss> signal NOT the state.
The state is set one clock after the signal and would therefore slow down the reaction time. Also the state can only be cleared after a
GetStatus or GetFullStatus command which prevents the autonomous function.
Only <UV2> and <CPFail> are applicable for finishing the motion to the original target position:
<UV2> needs to be cleared to leave the Shutdown State
<CPFail> needs to be cleared to avoid a new HardStop after entering the GotoPos state
The <StepLoss> signal is used to block successive motions. Also this signal will be cleared after Vbb > UV1, making updates of
TagPos possible.
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