AMIS-30622 Datasheet, PDF (21/42 Pages) AMI SEMICONDUCTOR – I2C Microstepping Motordriver

AMIS-30622
VBB
UV1 9.8 V
After GetFullStatus1
<UV2> = '0'
UV2 ^{8.5 V}
<UV2> = '1'
no motion: <StepLoss> = '0'
motion: <StepLoss> = '1'
t
9.2.2.7. Motor shutdown mode
A motor shutdown occurs when:
1. The chip temperature rises above the thermal shutdown threshold Ttsd (see § 5 DC-Parameters)
2. The battery voltage goes below UV2 (see § 5 DC-Parameters)
3. Flag <ElDef> = ‘1’, meaning an electrical problem is detected on one or both coils
4. Flag <CPFail> = ‘1’, meaning there is a charge pump failure
A motor shutdown leads to the followings:
• H-bridges in high impedance mode
• The TagPos register is loaded with the ActPos (to avoid any motion after leaving the motor shutdown
mode)
The I²C interface remains active, being able to receive orders or send status.
The conditions to get out of a motor shutdown mode are:
• Reception of a GetFullStatus1 command AND
• The four above causes are no more detected
Which leads to H-bridges in Ihold mode. Hence the circuit is ready to execute any positioning command.
This can be illustrated in the following sequence given as an application tip. The Master can check whether there
is a problem or not and decide which application strategy to adopt.
Tj ≥ Tsd or
Vbb ≤ UV2 or
<ElDef> = ‘1’ or
<CpFail> = ‘1’
SetPosition
frame
GetFullStatus1
GetFullStatus1
↓
↑
↑
↑…
- The circuit is driven in
motor shutdown
mode
- The application is not
aware of this
- The position set-point
is updated by the I²C
Master
- Motor shutdown
mode ⇒ no motion
- The application is still
unaware
- The application is
aware of a problem
- Possible confirmation
of the problem
- Reset <TW> or <TSD> or <UV2> or <StepLoss>
or <ElDef> or <CPFail> by the application
- Possible new detection of over temperature or
low voltage or electrical problem ⇒ Circuit sets
<TW> or <TSD> or <UV2> or <StepLoss> or
<ElDef> or <CPFail> again at ‘1’
Important
While in shutdown mode, since there is no hold current in the coils, the mechanical load can cause a step
loss, which indeed cannot be flagged by the AMIS-30622.
Warning
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