NCP1230GEVB ON Semiconductor, NCP1230GEVB Datasheet - Page 18

• Manufacturer Part Number: NCP1230GEVB
• Description: EVAL BOARD FOR NCP1230G
• Manufacturer: ON Semiconductor

Specifications of NCP1230GEVB

• Design Resources: NCP1230 EVB BOM NCP1230GEVB Gerber Files NCP1230 EVB Schematic
• Main Purpose: AC/DC, Primary Side
• Outputs And Type: 1, Isolated
• Power - Output: 90W
• Voltage - Output: 18.6V
• Current - Output: 4.74A
• Voltage - Input: 85 ~ 265VAC
• Regulator Topology: Flyback
• Frequency - Switching: 47kHz
• Board Type: Fully Populated
• Utilized Ic / Part: NCP1230
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: NCP1230G
• Other names: NCP1230GEVBOS

Frequency Jittering
signature by spreading out the average switching energy
around the controller operating switching frequency. The
Thermal Protection
integrated circuit in the event that the maximum junction
temperature is exceeded. When activated (165°C typically)
the controller turns off the PWM Drive Output. When this
occurs, Vcc will drop (the rate is dependent on the NCP1230
loading and the size of the Vcc capacitor) because the
controller is no longer delivering drive pulses to the
auxiliary winding charging up the Vcc capacitor. When Vcc
Frequency jittering is a method used to soften the EMI
An internal Thermal Shutdown is provided to protect the
Figure 41. An Internal Ramp is used to Introduce Frequency Jittering on the Oscillator Saw Tooth
62.4 kHz
Internal Ramp
65 kHz
http://onsemi.com
5 ms
18
67.6 kHz
NCP1230 offers a nominal ±6.4% deviation of the nominal
switching frequency. The sweep sawtooth is internally
generated and modulates the clock up and down with a 5 ms
period. Figure 41 illustrates the NCP1230 behavior:
drops below 4.0 volts and the Vccreset circuit is activated,
the controller will restart. If the user is using a fixed bias
supply (the bias supply is provided from a source other than
from an auxiliary winding, refer to the typical application )
and Vcc is not allow to drop below 4.0 volts under a thermal
shutdown condition, the NCP1230 will not restart. This
feature is provided to prevent catastrophic failure from
accidentally overheating the device.
Internal Sawtooth