Datasheet

NCL30082
http://onsemi.com
27
Brown−out
In order to protect the supply against a very low input
voltage, the NCL30082 features a brown−out circuit with a
fixed ON/OFF threshold. The controller is allowed to start
if a voltage higher than 1 V is applied to the VIN pin and
shuts−down if the VIN pin voltage decreases and stays
below 0.9 V for 50 ms nominal. Exiting a brown−out
condition overrides the hiccup on V
CC
(V
CC
does not wait
to reach V
CC(off)
) and the IC immediately goes into startup
mode (I
CC
= I
CC(start)
).
+
−
Vbulk
VIN
BO_NOK
50−ms blanking time
1 V if BONOK high
0.9 V if BONOK low
Figure 60. Brown−out Circuit
Figure 61. Brown−Out Chronograms (Valley Fill circuit is used)
0
40.0
80.0
120
160
1
10.0
12.0
14.0
16.0
18.0
2
300m
500m
700m
900m
1.10
3
46.1m 138m 231m 323m 415m
time in seconds
0
2.00
4.00
6.00
8.00
4
V
CC
V
Bulk
V
pinVIN
BO_NOK
(V) (V)(V) (V)
BO_NOK low
=> Startup mode
50−ms Timer
V
BO(on)
V
BO(off)
V
CC(on)
V
CC(off)