NCP1393B ON Semiconductor, NCP1393B Datasheet - Page 14

• Manufacturer Part Number: NCP1393B
• Description: High-Voltage Half-Bridge Driver
• Manufacturer: ON Semiconductor

www.DataSheet4U.com
controller restart to let the BO input voltage stabilize (there
can be connected big capacitor to the BO input and the I
is only 18.2 mA so it will take some time to discharge). Once
the 50 ms one shoot pulse ends the BO comparator is
supposed to either hold the I
voltage level is not sufficient) or let it turned OFF (if the bulk
voltage is higher than V
better understanding on how the BO input works.
measurement as long as the NTC and the optocoupler are not
activated. As soon as the secondary optocoupler senses an
The High−Voltage Driver
high−voltage section. The device incorporates an upper
The I
On Figure 29, Q1 is blocked and does not bother the BO
Figure 30 shows the internal architecture of the
V
BO
out
current sink is turned ON for 50 ms after any
Figure 29. Adding a Comparator on the BO Pin Offers a Way to Latch−Off the Controller
bulk1
Figure 28. BO Input Functionality − V
). See Figures 25 through 28 for
BO
sink turned ON (if the bulk
NTC
V
Q1
CC
V
bulk
R
R
upper
lower
http://onsemi.com
BO
14
BO
bulk
Latched−Off Protection
fully turned−off and stay latched. This can happen in
presence of an overvoltage (the feedback loop is drifting) or
when an overtemperature is detected. Due to the addition of
a comparator on the BO Pin, a simple external circuit can lift
up this pin above V
disable pulses. The V
6.5 V typically to reset the controller.
OVP condition, or the NTC reacts to a high ambient
temperature, Q1 base is brought to ground and the BO Pin
goes up, permanently latching off the controller.
UVLO circuitry that makes sure enough V
the upper side MOSFET. The V
I
BO
There are some situations where the converter shall be
SW
< V
bulk2
, PFC Start Follows
+
−
+
−
V
V
ref
refBO
+
latch
−
+
−
latch
CC
High Level for 50 ms After V
needs to be cycled down below
(2 V typical) and permanently
20ms
Filter
20ms
Filter
CC
for floating driver section
To PFC Delay
gs
to Permanent Latch
BO_OK
CC
is available for
On