Application Examples; A High Efficiency, 65 W Universal Input Power Supply (Innoswitch3-Ce) - Power integrations InnoSwitch3 Application Note

AN-72

Application Examples

BR1
GBU4J-BP
49.9 kΩ
600 V
1/8 W
1.80 MΩ
1 4
L1
15 mH
2 3
1.80 MΩ
R1 R2
C2
1.5 MΩ 2 MΩ
120 µF
400 V
C1
220 nF
275 VAC
t
RT1
F1 O
3.15 A 2.5 Ω
90 - 265
VAC
L N
TP1 TP2
Figure 26. Schematic of DER-535 65 W, 19 V Power Supply using INN3168C.
A High Efficiency, 65 W Universal Input Power Supply
(InnoSwitch3-CE)
The circuit shown in Figure 26 delivers 65 W (19 V at 3.4 A) at higher
than 90% average efficiency from 90 VAC to 265 VAC input using
INN3168C.
The bleeding resistors, R1 and R2, are used to discharge the stored
energy in C1 to meet safety requirement. The input capacitor C2 is
sufficient to maintain full output power delivery at 90 VAC input, and
Resistors R6, R7, and R8 provide line voltage sensing. At
approximately 100 V DC, the current through these resistors exceeds
the line undervoltage threshold, which enables U1. At approximately
420 V DC, the current through these resistors exceeds the line
overvoltage threshold, disabling U1. A low cost RCD clamp formed by
D1, R3, R4, and C3 limits the peak drain voltage due to the interaction
of transformer leakage reactance with output trace inductance.
www.power.com
C6
680 pF
250 VAC
1 FL1
C3
6
R3
2.2 nF
100 kΩ
630 V
R6
2
1%
R4
NC
47 Ω
2 W
D1
R7
FR107G
9
1%
4
3
R8
5
1%
T1
PQ26/20
D2
DFLR1200-7
200 V
D D V
CONTROL
R5
5.1 kΩ
1/10 W
S S BPP
InnoSwitch3-CE
C4 C5
INN3168C-H101
22 µF 4.7 µF
50 V
50 V
R13
143 kΩ
1%
1/8 W
C11
560 µF
35 V
C10
R11 2.2 nF
12 Ω 250 V
Q1
AO4294
C8
10 nF
R9
47 Ω
1/10 W
C7
2.2 µF
25 V
FB
IS
U1
The secondary-side of the INN3168C provides output voltage and
output current sensing, and provides drive to a synchronous
rectification MOSFET. Output rectification for the 19 V output is
provided by SR FET Q1. Very low ESR capacitors, C11 and C12,
provide filtering. RC snubber network comprising R11 and C10 for Q1
damps high frequency ringing across the SR FET, which results from
leakage of the transformer windings and the secondary trace.
Capacitor C8 protects U1 from ESD. Adding a small SMD ceramic
capacitor between the OUTPUT VOLTAGE pin and the GROUND pin
improves ESD and surge protection. The OVP sensing Zener diode,
VR1, provides secondary-side output over voltage protection via R12.
Output common mode choke L2 reduces high frequency common
mode noise and protects U1 from common mode surge.
A heat spreader is required to keep the InnoSwitch3 device below
110 °C when operating under full load, low-line, while at maximum
ambient temperature.
Application Note
L2
C12 155 µH
1 4
560 µF
D3
35 V
DFLR1200-7
200 V
2 3
R14
R12
10 kΩ
100 Ω
1%
1/10 W
1/16 W
C9
330 pF
50 V
VR1
MMSZ5232B-7-F
R10
0.007 Ω
1%
1/2 W
PI-8430-082018
19 V, 3.4 A
TP3
C14
1 µF
100 V
RTN
33
Rev. A 10/18