lv8740v ON Semiconductor, lv8740v Datasheet - Page 16

• Manufacturer Part Number: lv8740v
• Description: Pwm Current Control Stepping Motor Driver
• Manufacturer: ON Semiconductor

(11) Current control operation specification
In each current mode, the operation sequence is as described below :
Above operations are repeated. Normally, the SLOW (+FAST) DECAY mode continues in the sine wave increasing
direction, then entering the FAST DECAY mode till the current is attenuated to the set level and followed by the SLOW
DECAY mode.
• At rise of chopping frequency, the CHARGE mode begins.(The section in which the CHARGE mode is forced
• The coil current (ICOIL) and set current (IREF) are compared in this forced CHARGE section.
(Sine wave decreasing direction)
(Sine wave increasing direction)
STEP
Coil current
fchop
Current mode
STEP
Coil current
fchop
Current mode
regardless of the magnitude of the coil current (ICOIL) and set current (IREF) exists for 1/16 of one chopping cycle.)
When (ICOIL<IREF) state exists in the forced CHARGE section ;
When (ICOIL<IREF) state does not exist in the forced CHARGE section;
Set current
CHARGE mode up to ICOIL ≥ IREF, then followed by changeover to the SLOW DECAY mode, and finally
by the FAST DECAY mode for the 1/16 portion of one chopping cycle.
The FAST DECAY mode begins. The coil current is attenuated in the FAST DECAY mode till one cycle of
chopping is over.
CHARGE
CHARGE
Forced CHARGE
section
Forced CHARGE
section
SLOW
SLOW
Set current
FAST
FAST
LV8740V
Set current
Set current
Forced CHARGE
section
CHARGE
SLOW
FAST
FAST
CHARGE
SLOW
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