Application Brief
Off-line isolated power supply 3 W 5 V
reference design
Extremely low standby power consumption based on
Key features
CoolSET™ current mode controller
Power conversion with solid
performance and more
››Input voltage range 180–265 V AC
››Efficiency > 75 percent
››Conducted EMI compliant with
EN55022 class B
››Stand-by power < 13 mW
››Vout ripple (peak-to-peak) < 100 mV
››Small form factor (board dimension):
50 mm x 23.5 mm x 14 mm (L x W x H)
››Auto-restart protection modes
––Vcc over/undervoltage
––IC overtemperature
––Overload
––Open loop
The fast growing market around the Internet of Things (IoT) covers a wide range of appli­
cations. All of them have one thing in common, namely the ability to collect and exchange
data with each other. The microcontrollers, sensors, actuators, etc. embedded in each of
the devices stay connected to the network at all times. They are supplied by an efficient
low-power low-standby power supply for which the Infineon CoolSET™ family of integrat­
ed off-line power supply ICs is ideally suited.
In this reference design, the Infineon CoolSET™ ICE3RBR4765JG is used as a current-mode
flyback controller. It has a built-in 650 V CoolMOS™. This application operates in Discontinuous Conduction Mode (DCM), running at 65 kHz switching frequency. The output is
single 5 V 600 mA. Active burst mode operation provides extremely low standby power
consumption, < 13 mW over the input voltage range 180–265 V AC. Low EMI is achieved by
built-in frequency jitter and soft start operation.
Target applications
››Applications related to the Internet of Things (IoT)
––Standby power supply
––Power supply for microcontrollers
––Power supply for standalone sensors operating on a wired/wireless interface bus
››USB-power supply embedded in a wall plug
››Intelligent wall plug switched by wireless (with relay)
››Metering application
››General applications with small form factor in the power range 1 W to 3 W
Top and bottom side of the reference design
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Application Brief
Off-line isolated power supply 3 W 5 V
reference design
With CoolSET™ ICE3RBR4765JG
L1
68 µH
R2
330 kΩ
VCC
C6
4.7 µF
50 V
F1
L
U
V1
300 V
C1
1 µF
450 V
AC1 DC+
AC2 DC­
C2
1 µF
450 V
C3
n.a.
C5
1 nF
50 V
R3
6.8 Ω
1%
5V
D3
7
C9
180 µF
6.3 V
SS26
R13
12 Ω
1%
C10
330 µF
6.3 V
C11
10 µF
25 V
8
D2
ES1D
VCC
BA
FB
CS
NC1
10 Ω
0.75 W
T1
4
U1
ICE3RBR4765JG
R1
N
C4
D1
2200 pF STTH1R06A
C7
33 µF
35 V
BR1
MB6S
500 mA
1
5
GND
SGND
C8
1000 pF
GND
Drain
Drain
Drain
Drain
NC2
NC3
R5
n.a.
U2
VOL618A­3T
GND
R4
C12
R6
3.3 kΩ
33 nF
1 MΩ
R7
102 kΩ
1%
Ref
Reference design schematic
R8
33 kΩ
1%
U3
LMV431
SGND
n.a. = not assembled
Order information
Type
Description
Ordering code
REF-3W-IOT-COOLSET
Power supply 3 W 5 V reference design
SP001642672
Published by
Infineon Technologies AG
81726 Munich, Germany
© 2016 Infineon Technologies AG.
All Rights Reserved.
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Order Number: B121-I0380-V1-7600-EU-EC-P
Date: 10 / 2016
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