NCP1237 ONSEMI [ON Semiconductor], NCP1237 Datasheet - Page 10

• Manufacturer Part Number: NCP1237
• Description: Fixed Frequency Current Mode Controller for Flyback Converters
• Manufacturer: ONSEMI [ON Semiconductor]

High−Voltage Current Source (Dynamic Self−Supply)
with Built−in Brown−out Detection
The NCP1237 HV pin can be connected either to the
rectified bulk voltage, or to the ac line through a rectifier.
Startup
VCC
HV
Figure 4. HV Startup Current Source Functional Schematic
I
start
DETAILED DESCRIPTION
http://onsemi.com
Control
+
+
+
+
V
V
V
V
CC(on)
CC(min)
CC(off )
CC(reset)
+
+
+
+
−
−
−
−
10
t
blanking
UVLO(blank)
IC Start
Reset
R
S
Q
UVLO
TSD