ICE2QR0665G Datasheet, PDF (11/21 Pages) Infineon Technologies AG – Off-Line SMPS Quasi-Resonant PWM Controller with integrated 650V CoolMOS® and startup cell in DSO-16/12

CoolSET^® - Q1
ICE2QR0665G
Functional Description
Mode. This is helpful to decrease the output voltage
undershoot.
VFB
VFBLB
VFBBOn
VFBBOff
Entering
Active Burst
Mode
Leaving
Active Burst
Mode
VFBEB
time to 7^th zero and
t
V_CS
blanking Window (tBEB)
1.0V
VCSB
Current limit level
during Active Burst
Mode
VVCC
t
VVCCoff
V_O
t
Max. Ripple < 1%
reset and the main power switch is then kept off. After the
VCC voltage falls below the threshold 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 24ms, the
IC enters auto-restart mode. The blanking time here enables
the converter to provide a max. power in case the increase in
V_FB is due to a sudden load increase. 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. This latch off mode can only
be reset if the Vcc <6.23V.
If the junction temperature of IC exceeds 140 °C, the IC
enters into autorestart mode (OTP).
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.
During latch-off protection mode, the VCC voltage drops to
10.5V and then the startup cell is activated. The VCC voltage
is then charged to 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 ICE2QR0665G. Once the gate voltage is high and
longer than t_OnMAx, the switch is turned off immediately.
t
Figure 8
Signals in Active Burst Mode
3.6
Protection Functions
The IC provides full protection functions. The following
table summarizes these protection functions.
Table 2
Protection features
VCC Overvoltage
VCC Undervoltage
Overload/Open Loop
Over temperature
Output Overvoltage
Short Winding
Auto Restart Mode
Auto Restart Mode
Auto Restart Mode
Auto Restart Mode
Latched Off Mode
Latched Off Mode
During operation, the VCC voltage is continuously
monitored. In case of an under- or an over-voltage, the IC is
Version 2.0
11
July 4, 2011