NCP1336 ONSEMI [ON Semiconductor], NCP1336 Datasheet - Page 12

• Manufacturer Part Number: NCP1336
• Description: Quasi-Resonant Current Mode Controller for High Power Universal Off-Line Supplies
• Manufacturer: ONSEMI [ON Semiconductor]

circuitry, the controller is locked in this valley until the FB
voltage decreases of 0.6 V (“n+1” valley activates) or
increases of 0.8 V (“n−1” valley activates). The peak current
When an “n” valley is asserted by the valley selection
Laux
ZCD
FB
Ct
10 V
ESD
Rpullup
VDD
ICt
Figure 6. Valley Selection and VCO Internal Schematic
Figure 7. Peak Current Setpoint and Selected Valley
Setpoint
DRV
Ct
Discharge
vs. FB Voltage when FB Voltage Decreases
VDD
Ct
Vth
V
FBth
Tblank
http://onsemi.com
+
−
+
−
+
−
+
−
−
+
+
−
Leakage
Blanking
12
adjusts to deliver the necessary output power (See Figure 7
and Figure 8). Each comparator has a hysteresis of 600 mV
that helps to stabilize the valley selection in case of
oscillations on FB voltage.
VCO
Time
Out
Demag
CS Comparator
Decimal Counter
1st
4th
2nd
3rd
1
2 3 4
CLK
rst
S
R
Q
Q
DRV