Functional description
L6219DSA
2.4
Single-pulse generator
The pulse generator is a monostable triggered on the positive going edge of the comparator
output. The monostable output is high during the pulse time, toff, which is determined by the
time components R
t
and C
t
.
t
off
= 1.1 · R
t
C
t
The single pulse switches off the power feed to the motor winding, causing the winding
current to decrease during t
off
. If a new trigger signal should occur during t
off
, it is ignored.
2.5
Output stage
The output stage contains four Darlington transistors (source drivers) four saturated
transistors (sink drivers) and eight diodes, connected in two H bridge.
Figure 4.
Principle operating sequence
The source transistors are used to switch the power supplied to the motor winding, thus
driving a constant current through the winding. It should be noted however, that is not
permitted to short circuit the outputs.
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