L6472 STMICROELECTRONICS [STMicroelectronics], L6472 Datasheet - Page 36

• Manufacturer Part Number: L6472
• Description: dSPIN fully integrated microstepping motor driver
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Phase current control
7.3
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Auto-adjusted fast decay during the falling steps
When the target current is decreased by a microstep change (falling step), the device
performs a fast decay in order to reach the new value as fast as possible. Anyway,
exceeding the fast duration may cause a strong ripple on the step change. The L6472
automatically adjusts these fast decays reducing the current ripple.
At reset, the fast decay value (t
value is doubled every time, within the same falling step, an extra fast decay is necessary to
obtain an ON time greater than TON_MIN. The maximum t
FALL_STEP.
At the next falling step, the system uses the last t
Stopping the motor or reaching the current sinewave zero crossing causes the current
control system to return to the reset state.
Figure 18. Adaptive decay switch from normal to slow+fast decay mode and
viceversa
Doc ID 022729 Rev 1
FALL
) is set to FALL_STEP/4 (T_FAST register). The t
FALL
value of the previous falling step.
FALL
value is equal to
FALL
L6472