NCP1203GEVB ON Semiconductor, NCP1203GEVB Datasheet - Page 6

• Manufacturer Part Number: NCP1203GEVB
• Description: EVAL BOARD FOR NCP1203G
• Manufacturer: ON Semiconductor

Specifications of NCP1203GEVB

• Design Resources: NCP1203GEVB BOM NCP1203GEVB Gerber Files NCP1203 EVB Schematic
• Main Purpose: AC/DC, Primary Side
• Outputs And Type: 1, Isolated
• Voltage - Output: 19V
• Current - Output: 4A
• Voltage - Input: 85 ~ 230VAC
• Regulator Topology: Flyback
• Frequency - Switching: 60kHz
• Board Type: Fully Populated
• Utilized Ic / Part: NPC1200
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: NCP1203G
• Other names: NCP1203GEVBOS

corresponding time constant of 18 s gives a ramp maximum
peak voltage of:
with t = 0.45 1/61 k. This provides an available ramp level
of 677 mV/ s (S). By setting Radd2 to 1 k , Radd1 can be
computed using the following formula:
for m = 60%. Final tweak gives an 18k resistor for Radd1.
hv
+
Vinput
120
Vadj
Figure 8. The Simplified Simulation Schematic Helps to Determine All the Component Key Parameters
21
Istartup
Radd1 + 1 k @
Vcc + Vdrv @ 1 * e
1
2
3
4
NCP1200
NCP1200
Fs = 65 k
1.0 k
18 k
R8
R9
IC = 14
+
12
47 F
Cvcc
Vclamp
100
S @ m
8
7
6
5
R5
m
S
5
23
Drv
+ 22.5 kW
1
t
18 k
R10
Vcc
+ 5 V
drv
24
18
R2
4.7 k
D4
MUR160
C6
1.0 nF
200 m
Rg
10
Iprim
R3
D1
1N4148
20
C3
100 nF
700 H
Iclp
http://onsemi.com
7
d
AND8076/D
(21)
Lp
X1
XFMR
RATIO = -0.166
10
16
+
Rsense
0.33
Lleak
12 H
6
Vdrain
Vsense
Component Constraints
precisely determine all the component constraints and thus
calculate the necessary amount of heatsink they need. The
simulation schematic we adopted is given on Figure 8 and
shows the NCP1200 wired as recommended in the data
sheet. Please note that the simulation fixture has been
simplified to allow faster simulation time. For instance, the
TL431 and its network usually hamper the simulation time
to find out the right operating point. A Zener diode and a
resistor help finding it in a much quicker way.
Idrain
In this section, we will see how Spice can help us to
4
Iripple1
Isec
IC = 16.5
15
X6
MBR20100
3.3 mF
Resr1
11 m
8
C1
VFB
1
9
Vsec
19
14
R15
1.0 k
100 H
X5
SFH610A
D3
1N963
L1
Iripple2
31
IC = 16.5
10 m
220 F
R10
300 m
Resr2
C2
17
Iout
32
Vout
Rload
3.7
Vout