NCP1012GEVB ON Semiconductor, NCP1012GEVB Datasheet - Page 12

• Manufacturer Part Number: NCP1012GEVB
• Description: EVAL BOARD FOR NCP1012G
• Manufacturer: ON Semiconductor

Specifications of NCP1012GEVB

• Design Resources: NCP1012 Eval Brd BOM NCP1012GEVB Gerber Files NCP1012 Eval Brd Schematic
• Main Purpose: AC/DC, Primary Side
• Outputs And Type: 1, Isolated
• Voltage - Output: 12V
• Voltage - Input: 230VAC
• Regulator Topology: Flyback
• Frequency - Switching: 100kHz
• Board Type: Fully Populated
• Utilized Ic / Part: NCP1012
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Power - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: NCP1012G
• Other names: NCP1012GEVBOS

Lowering the Standby Power with Skip- -Cycle
power by skipping unwanted cycles at light loads.
However, the recurrent frequency in skip often enters the
audible range and a high peak current obviously generates
acoustic noise in the transformer. The noise takes its origins
in the resonance of the transformer mechanical structure
Skip- -cycle offers an efficient way to reduce the standby
Figure 18. A more detailed view of the NCP101X offers better insight on how to
Permanent
Figure 19. The burst frequency becomes so low that it is difficult to keep
Latch
Vclamp = 8.7 V typ.
VCC
VCC
ON
OFF
= 8.5 V
= 7.5 V
an adequate level on the auxiliary V
+
+
properly wire an auxiliary winding.
+
--
--
+
>30 ms
--
+
http://onsemi.com
+
12
I > 7.4m
(Typ.)
Startup Source
Ground
which is excited by the skipping pulses. A possible
solution, successfully implemented in the NCP1200 series,
also authorizes skip- -cycle but only when the power
demand has dropped below a given level. At this time, the
peak current is reduced and no noise can be heard.
Figure 20 pictures the peak current evolution of the
NCP101X entering standby.
V
CC
Drain
+
CVcc
Rlimit
CC
. . .
+
Caux
D1
Laux