AN1625 STMicroelectronics, AN1625 Datasheet - Page 18

• Manufacturer Part Number: AN1625
• Description: L6235 THREE PHASE BRUSHLESS DC MOTOR DRIVER
• Manufacturer: STMicroelectronics

AN1625 APPLICATION NOTE
The total intervention time is
where
t
applied to R
The external RC network, C
t
at least 100µs for t
The internal open drain can also be turned on if the device experiences an over temperature (OVT) condition.
The OVT will cause the device to shut down when the die temperature exceeds the OVT threshold (T
typ.).
Since the OVT is also connected directly to the gate drive circuit (see Figure 1), all the Power DMOS will shut
down, even if EN pin voltage is still over V
threshold (150 °C typ.), the open drain turns off, C
turned on back.
18/39
OCD(OFF)
DELAY
) and a safe disable time (long t
, t
OCD(ON)
EN
.
DISABLE
, t
D(ON)EN
are recommended, keeping the delay time below 1÷2µs at the same time.
EN
, t
in particular, must be chosen obtaining a reasonable fast OCD intervention (short
D(OFF)EN
t
DE LAY
V
t
E N F ALL
EN LO W
DISABLE
, and R
=
th(OFF)
t
OCD O N
=
). Figure 19 shows both t
=
OPDR
R
V
. When the junction temperature falls below the OVT turn-off
T H O FF
O PDR
EN
are device intrinsic parameters, V
is recharged up to V
+
t
E N F ALL
C
E N
e


t
------------------------------------------------- -
D O FF
ln
R


O PD R
+
------------------------ -
V
+
T H OF F
t
D O FF EN
t
V
O CD O FF
DD
C
E N
DISABLE
TH(ON)




and t
and then the PowerDMOS are
DELAY
DD
is the pull-up voltage
as a function of C
J
>165 °C
EN
: