User Manual

AND8399/D
http://onsemi.com
10
Figure 12. Voltage Measured on the Coil and SLA−pin for ‘Not Transparent’ Mode
t
I
coil
I
coil
t
Coil Current
Zero Crossing
Previous
Microstep
Next
Microstep
V
coil
t
V
BB
+0.6V
V
BEMF
Next step Next step
V
SLA
t
Transparent Mode
V
SLA
t
Not Transparent Mode
PWM Rate
Transient
behavior
Last sample before leaving
zero crossing is retained.
SLA voltage is only updated after
current−less state is left+ a certain
delay (50us at room temp).
Bemf of previous
zero crossing.
Current Decay