ICE2QS03G_16 Datasheet, PDF (13/28 Pages) Infineon Technologies AG – 45 W adapter demo board

45 W adapter demo board
Using the new 800 V CoolMOS™ P7 and ICE2QS03G quasi-resonant PWM controller
Demo board overview
Section
Output ratings
Parameter
Nominal output voltage
Tolerance
Output current
Output power
Line regulation
Load regulation
Output ripple
Quiescent power draw
Mechanical
Switching frequency
Dimensions
Environmental Ambient operating temperature
Specification
19.0 V
2%
2.4 A
45 W
0.5%
0.5%
100 mV_PP
42 mW @100 V_AC
94 mW @265 V_AC
25 – 60 kHz
Length: 10.0 cm (3.94 in.)
Width: 3.7 cm (1.46 in.)
Height: 2.6 cm (1.02 in.)
-25°C to 50°C
6.3
Demo board features
• Fold back point protection - For a quasi-resonant flyback converter, the maximum possible output power is
increased when a constant current limit value is used across the entire mains input voltage range. This is
usually not desired as this will increase the cost of the transformer and output diode in the case of output
over power conditions. The internal fold back protection is implemented to adjust the V_CS voltage limit
according to the bus voltage. Here, the input line voltage is sensed using the current flowing out of the ZC pin,
during the MOSFET on-time. As the result, the maximum current limit adjusts with the AC line voltage.
• V_CC over voltage and under voltage protection - During normal operation, the Vcc voltage is continuously
monitored. When the V_cc voltage increases to VVCC OVP or V_cc voltage falls below the under voltage lock out
level VVCC off, the IC will enter into auto restart mode.
• Over load/open loop protection - In the case of an open control loop, the feedback voltage is pulled up with
an internal block. After a fixed blanking time, the IC enters into auto restart mode. In case of a secondary
short-circuit or overload, the regulation voltage V_FB will also be pulled up, the same protection is applied and
the IC will auto restart.
• Adjustable output overvoltage protection - During the off-time of the power switch, the voltage at the zero-
crossing pin, ZC, is monitored for output overvoltage detection. If the voltage is higher than the preset
threshold 3.7 V for a preset period of 100 μs, the IC is latched off.
• Auto restart for over temperature protection - The IC has a built-in over temperature protection function.
When the controller’s temperature reaches 140 °C, the IC will shut down the switch and enters into auto
restart. This can protect the power MOSFET from overheating.
• Short winding protection - The source current of the MOSFET is sensed via external resistors, R15 and R16. If
the voltage at the current sensing pin is higher than the preset threshold VCSSW of 1.68 V during the on-time
of the power switch, the IC is latched off. This constitutes a short winding protection. To avoid an accidental
latch off, a spike blanking time of 190 ns is integrated in the output of internal comparator.
Application Note
13
Revision 1.0
2016-06-27