ice3ar4780jz Infineon Technologies Corporation, ice3ar4780jz Datasheet - Page 17

• Manufacturer Part Number: ice3ar4780jz
• Description: Off-line Smps Current Mode Controller With Integrated 800v Coolmos And Startup Cell Brownout & Frequency Jitter In Dip- 7
• Manufacturer: Infineon Technologies Corporation

Figure 26
3.7.3
The IC provides Auto Restart mode as the major protection
feature. Auto Restart mode can prevent the SMPS from
destructive states. There are 2 kinds of auto restart mode; odd
skip auto restart mode and non switch auto restart mode. Odd
skip auto restart mode is that there is no detect of fault and
no switching pulse for the odd number restart cycle. At the
even number of restart cycle the fault detect and soft start
switching pulses maintained. If the fault persists, it would
Version 2.0
V
V
csth_burst
V
10.5V
3.4mA
620uA
FB_burst
3.2V
3.5V
Blanking Timer
V
4.0V
V
I
V
V
FBB
VCC
csth
OUT
CS
VCC
20ms Blanking Time
Current limit level
during Active Burst
Mode
Protection Modes
Signals in Active Burst Mode
Entering
Active Burst
Mode
Leaving
Active Burst
Mode
t
t
t
t
t
t
17
continue the auto-restart mode. However, if the fault is
removed, it can release to normal operation only at the even
number auto restart cycle (Figure 27).
Figure 27
Non switch auto restart mode is similar to odd skip auto
restart mode except the start up switching pulses are also
suppressed at the even number of the restart cycle. The
detection of fault still remains at the even number of the
restart cycle. When the fault is removed, the IC will resume
to normal operation at the even number of the restart cycle
(Figure 28).
Figure 28
The main purpose of the odd skip auto restart is to extend the
restart time such that the power loss during auto restart
protection can be reduced. This feature is particularly good
for smaller Vcc capacitor where the restart time is shorter.
The following table lists the possible system failures and the
corresponding protection modes.
VCC Over voltage (1)
VCC Over voltage (2)
Over load
Open Loop
VCC Undervoltage
Short Optocoupler
10.5V
V
10.5V
V
17V
V
17V
V
VCC
VCC
CS
CS
detected
detected
Fault
Fault
Odd skip auto restart waveform
non switch auto restart waveform
No detect
No detect
Odd skip Auto Restart Mode
Odd skip Auto Restart Mode
Odd skip Auto Restart Mode
Odd skip Auto Restart Mode
Non switch Auto Restart Mode
Non switch Auto Restart Mode
Functional Description
Startup and detect
Startup and detect
CoolSET
No switching
No detect
No detect
ICE3AR4780JZ
26 Aug 2010
®
-F3R80
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