ICE2QS03G Infineon Technologies, ICE2QS03G Datasheet - Page 11

• Manufacturer Part Number: ICE2QS03G
• Description: IC CTRLR PWM QUASI-RESON DSO8
• Manufacturer: Infineon Technologies

Specifications of ICE2QS03G

• Output Isolation: Isolated
• Frequency Range: 52kHz
• Voltage - Input: 11.2 V ~ 27 V
• Operating Temperature: -25°C ~ 130°C
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

the output flip-flop will be reset by one of these signals
which come first.
If the output load is still low, the feedback signal
decreases as the PWM section is operating. When
feedback signal reaches the low threshold V
the internal bias is reset again and the PWM section is
disabled until next time regultaion siganl increases
beyond the V
Mode the feedback signal is changing like a saw tooth
between 3.0V and 3.6V shown in
3.5.3
The feedback voltage immediately increases if there is
a high load jump. This is observed by one comparator.
As the current limit is 34% during Active Burst Mode a
certain load is needed so that feedback voltage can
exceed V
maximum current can now be provided to stabilize V
In addition, the up/down counter will be set to 1
immediately after leaving Active Burst Mode. This is
helpful to decrease the output voltage undershoot.
Figure 9
Version 2.1
V
V
V
V
V
V
V
1.0V
V
V
FBBOn
FBBOff
V
VCCoff
FB
CSB
FBLB
FBEB
O
VCC
CS
LB
Current limit level
during Active Burst
Mode
Leaving Active Burst Mode Operation
Blanking Window (t
(4.5V). After leaving active busrt mode,
Signals in Active Burst Mode
BH
Max. Ripple < 1%
threshold. If working in Active Burst
Entering
Active Burst
Mode
BEB
)
Leaving
Active Burst
Mode
Figure
9.
BL
(3.0V),
t
t
t
t
O
.
11
3.6
The IC provides full protection functions. The following
table summarizes these protection functions.
Table 2
During operation, the VCC voltage is continuously
monitored. In case of an under- or an over-voltage, the
IC is reset and the main power switch is then kept off.
After the VCC voltage falls below the threshold V
the startup cell is activated. The VCC capacitor is then
charged up. Once the voltage exceeds the threshold
V
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
high power in case the increase in V
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
IC is latched off after the preset blanking time.
If the junction temperature of IC exceeds 140
enter into autorestart mode.
If the voltage at the current sensing pin is higher than
the preset threshold v
switch, the IC is latched off. This is short-winding
protection.
During latch-off protection mode, when the VCC
voltage drops to 10.5V,the startup cell is activated and
the VCC voltage is charged to 18V then the startup cell
is shut down again and repeats the previous procedure.
There is also a maximum on time limitation inside
ICE2QS03G. Once the gate voltage is high longer than
t
OnMAx
VCCon
VCC Overvoltage
VCC Undervoltage
Overload/Open Loop
Over temperature
Output Overvoltage
Short Winding
Quasi-Resonant PWM Controller
, it is turned off immediately.
, the IC begins to operate with a new soft-start.
Protection Functions
Protection features
CSSW
Functional Description
during on-time of the power
Auto Restart Mode
Auto Restart Mode
Auto Restart Mode
Auto Restart Mode
Latched Off Mode
Latched Off Mode
February 5, 2010
ICE2QS03G
FB
is due to a
ZCOVP
0
C, the IC
VCCoff
, the
,