NCP1028 ON Semiconductor, NCP1028 Datasheet - Page 2

• Manufacturer Part Number: NCP1028
• Description: High?voltage Switcher For Medium Power Offline Smps
• Manufacturer: ON Semiconductor

85-265 VAC
PIN FUNCTION DESCRIPTION
*Optional component
Pin No.
1
2
3
4
5
-
7
8
Ramp Comp.
Brown-Out
Symbol
Drain
GND
OPP
V
FB
CC
-
Over Power Protection
Feedback Signal Input
Ramp Compensation
Powers the Internal
Drain Connection
+
Brown-Out and
The IC Ground
Latchoff Input
Function
Circuitry
in CCM
BO
-
Comp.*
Ramp
Figure 1. Typical Application
+
http://onsemi.com
This pin is connected to an external capacitor of typically 22 mF.
To extend the duty cycle operation in Continuous Conduction Mode (CCM),
pin 3 offers the ability to inject ramp compensation in the controller. If unused,
short this pin to V
By monitoring the bulk level via a resistive network, the circuit protects itself
from low mains conditions. If an external event brings this pin above 4.0 V,
the part fully latches off.
By connecting an optocoupler to this pin, the peak current setpoint is adjusted
accordingly to the output power demand.
The internal drain power switch circuit connection.
This unconnected pin ensures adequate creepage distance.
Driving this pin reduces the power supply capability in high line conditions. If
no Over Power Protection is needed, short this pin to ground.
-
NCP1028
+
2
1
2
3
4
NCP1028
CC
.
8
7
5
OPP*
Description
+
GND
V
out