ICE3BR2565JF Datasheet, PDF (18/36 Pages) Infineon Technologies AG – Off-Line SMPS Current Mode Controller with integrated 650V CoolMOS and Startup cell (frequency jitter Mode) in FullPak

CoolSET^®-F3R
ICE3BR2565JF
Functional Description
3.7.3.2
Auto Restart without extended blanking
time
Auto-restart BA
Enable
Signal
0.33V C9
1ms
counter
T_AE
25.5V
120us
VCC ^C2
Blanking
Time
UVLO
Auto Restart
Mode Reset
VVCC < 10.5V
Stop
gate
drive ^AutoRestart
mode
a trigger signal to the base of the externally added
transistor, T_AE at the BA pin. When the function is
enabled, the gate drive switching will be stopped and
then the IC will enter auto-restart mode if the signal
persists. To ensure this auto-restart function will not be
mis-triggered during start up, a 1ms delay time is
implemented to blank the unstable signal.
VCC undervoltage is the Vcc voltage drop below Vcc
turn off threshold. Then the IC will turn off and the start
up cell will turn on automatically. And this leads to Auto
Restart Mode.
Short Optocoupler also leads to VCC undervoltage.
When the FB pin is pulled low, there is no switching
pulse. Then the Vcc will drop to Vcc turn off threshold.
And it leads to Auto Restart Mode.
VCC
C1
20.7V
softs_period
Spike
&
Blanking
G1
30us
4.5V
C4
FB
Thermal Shutdown
T_j >130°C
Voltage
Reference
Control Unit
Figure 26 Auto Restart mode
There are 2 modes of V_CC overvoltage protection; one
is during soft start and the other is at all conditions.
The first one is V_VCC voltage is > 20.7V and FB is > 4.5V
and during soft_start period and the IC enters Auto
Restart Mode. The VCC voltage is observed by
comparator C1. The fault conditions are to detect the
abnormal operating during start up such as open loop
during light load start up, etc. The logic can eliminate
the possible of entering Auto Restart mode if there is a
small voltage overshoots of V_VCC during normal
operating.
The 2nd one is V_VCC >25.5V and last for 120us and the
IC enters Auto Restart Mode. This 25.5V Vcc OVP
protection is inactivated during burst mode.
The Thermal Shutdown block monitors the junction
temperature of the IC. After detecting a junction
temperature higher than 130°C, the Auto Restart Mode
is entered.
In case the pre-defined auto-restart features are not
sufficient, there is a customer defined external Auto-
restart Enable feature. This function can be triggered
by pulling down the BA pin to < 0.33V. It can simply add
Version 2.0
18
11 Sep 2008