ICE2QR1765G_14 Datasheet, PDF (16/27 Pages) Infineon Technologies AG – Off-Line SMPS Quasi-Resonant PWM Controller with integrated 650V CoolMOS? and startup cell in DSO-16/12

CoolSET™Q1
ICE2QR1765G
Functional Description
V_VCCoff, the startup cell is activated. The VCC capacitor is then charged up. Once the voltage exceeds the
threshold V_VCCon, the IC begins to operate with a new soft-start.
In case of open control loop or output over load, the feedback voltage will be pulled up. After a blanking time of
t_{OLP_B} (30ms), the IC enters auto-restart mode. The blanking time here enables the converter to provide a peak
power in case the increase in V_FB is due to a sudden load increase. This output over load protection is disabled
during burst mode.
During off-time of the power switch, the voltage at the zero-crossing pin is monitored for output over-voltage
detection. If the voltage is higher than the preset threshold V_ZCOVP, the IC is latched off after the preset blanking
time t_ZCOVP. This latch off mode can only be reset if the Vcc < V_VCCPD.
If the junction temperature of IC controller exceeds T_jCon (130 °C), the IC enters into OTP auto restart mode.
This OTP is disabled during burst mode.
If the voltage at the current sensing pin is higher than the preset threshold V_CSSW during on-time of the power
switch, the IC is latched off. This is short-winding protection. The short winding protection is disabled during
burst mode.
During latch-off protection mode, the VCC voltage drops to V_VCCoff (10.5V) and then the startup cell is activated.
The VCC voltage is then charged to V_VCCon (18V). The startup cell is shut down again. This action repeats again
and again.
There is also a maximum on time limitation implemented inside the CoolSET^TM Q1. Once the gate voltage is
high and longer than t_OnMax, the switch is turned off immediately.
Data Sheet
16
V2.1, 2014-04-01