NCP1205 ON Semiconductor, NCP1205 Datasheet - Page 4

• Manufacturer Part Number: NCP1205
• Description: Single Ended Pwm Controller Featuring Qr Operation And Soft Frequency Foldback
• Manufacturer: ON Semiconductor

Demag
HV
FB
Ct
1
2
3
4
Ri
Lasts more than 128 ms?
−−> Protection Circuitry
Last Pulse of Demag
Protection (OCP)
−
+
Over Current
V(−) < 1.5 V
+
DEMAG ?
−
after 4 ms
Rf
2.5 V
Figure 3. Internal Circuit Architecture for PDIP−8 Version
V
V
err
err
1/3
Max = 3 V
Min = 10 mV
−
+
http://onsemi.com
Internal V
4
1 V
Current Comparator
CC
V
Startup
err
Internal Regulator
Max T
R
V
T
CO
off
Flip−Flop
Clock
Feedback
= f (V
off
D
= f (Ct)
err
OVP
)
Q
UVLO
Internal Clamp
UVLO
200 ns L.E.B
Driver
2.8 V
L
H
= 7.2 V
= 15 V
+
−
+
−
18 k
8
7
6
5
V
DRV
I
GND
sense
CC