STMicroelectronics L6227 DMOS Evaluation Board EVAL6227PD EVAL6227PD Datenbogen
Produktcode
EVAL6227PD
DocID9453 Rev 2
19/32
L6227
Slow decay mode
32
Figure 14. Overcurrent protection simplified schematic
shows the overcurrent detection operation. The disable time t
DISABLE
before
recovering normal operation can be easily programmed by means of the accurate
thresholds of the logic inputs. It is affected whether by C
thresholds of the logic inputs. It is affected whether by C
EN
and R
EN
values and its
magnitude is reported in
. The delay time t
DELAY
before turning off the bridge when
an overcurrent has been detected depends only by C
EN
value. Its magnitude is reported in
.
C
EN
is also used for providing immunity to pin EN against fast transient noises. Therefore
the value of C
EN
should be chosen as big as possible according to the maximum tolerable
delay time and the R
EN
value should be chosen according to the desired disable time.
The resistor R
EN
should be chosen in the range from 2.2 K
to 180 K. Recommended
values for R
EN
and C
EN
are respectively 100 K
and 5.6 nF that allow obtaining 200 s
disable time.
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