AMIS-30621 LIN Micro-stepping Motor Driver
Data Sheet
14.2 Main Control and Register, OTP Memory + ROM
14.2.1. Power-up Phase
Power up phase of the AMIS-30621 will not exceed 10ms. After this phase, the AMIS-30621 is in shutdown mode, ready to receive LIN
messages and execute the associated commands. After power-up, the registers and flags are in the reset state; some of them being
loaded with the OTP memory content (see Table 18).
14.2.2. Reset State
After power-up or after a reset occurrence (e.g. a micro cut on pin VBB has made Vdd to go below VddReset level), the H-bridges will
be in high impedance mode, and the registers and flags will be in a predetermined position. This is documented in Table 18 and Table
19.
14.2.3. Soft Stop
A soft stop is an immediate interruption of a motion, but with a deceleration phase. At the end of this action, the register TagPos is
loaded with the value contained in register ActPosto avoid an attempt of the circuit to achieve the motion (see Table 18). The circuit is
then ready to execute a new positioning command, provided thermal and electrical conditions allow for it.
14.2.4. Sleep Mode
When entering sleep mode the stepper motor can be driven to its secure position. After which, the circuit is completely powered down,
apart from the LIN receiver, which remains active to detect dominant state on the bus. In case sleep mode is entered while a motion is
ongoing, a transition will occur towards secure position as described in Positioning and Motion Control provided SecPos is enabled.
Otherwise, SoftStopis performed.
Sleep mode can be entered in the following cases:
• The circuit receives a LIN frame with identifier 0x3C and first data byte containing 0x00 as required by LIN specification rev. 1.3. See
Sleepcommand.
• The LIN bus remains inactive (or is lost) during more than 25000 time slots (1.30s at 19.2kbit/s) after which a time-out signal switches
the circuit of sleep mode. See LIN Lost Behavior.
The circuit will return to normal mode if a valid LIN frame is received while entering the sleep mode (this valid frame can be addressed
to another slave).
14.2.5. Thermal Shutdown Mode
When thermal shutdown occurs, the circuit performs a SoftStopand goes to motor shutdown mode (see below).
14.2.6. Temperature Management
The AMIS-30621 monitors temperature by means of two thresholds and one shutdown level, as illustrated in Figure 16. The only
condition to reset flags <TW> and <TSD> (respectively thermal warning and thermal shutdown) is to be at a temperature lower than Ttw
and to get the occurrence of a GetStatusor a GetFullStatusLIN frame.
AMI Semiconductor – Sept. 2007, Rev 1.5
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