ICE3BR1065J_11 INFINEON [Infineon Technologies AG], ICE3BR1065J_11 Datasheet - Page 12

• Manufacturer Part Number: ICE3BR1065J_11
• Manufacturer: INFINEON [Infineon Technologies AG]

Within the soft start period, the duty cycle is increasing
from zero to maximum gradually (see Figure 12).
In addition to Start-Up, Soft-Start is also activated at
each restart attempt during Auto Restart.
Figure 13
The Start-Up time t
voltage V
Start Phase t
By means of Soft-Start there is an effective
minimization of current and voltage stresses on the
integrated CoolMOS
overshoot and it helps to prevent saturation of the
transformer during Start-Up.
Version 2.0
V
SOFTS32
4.0V
V
OUT
OUT
V
V
V
FB
Start Up Phase
SoftS
OUT
Soft-Start
is settled, must be shorter than the Soft-
t
t
Soft-Start
Start-Up
Start-Up
(see Figure 13).
®
, the clamp circuit and the output
before the converter output
t
t
t
12
3.5
Figure 14
3.5.1
The oscillator generates a fixed frequency of 65KHz
with frequency jittering of ±4% (which is ±2.6KHz) at a
jittering period of 4ms.
A capacitor, a current source and current sink which
determine the frequency are integrated. In order to
achieve a very accurate switching frequency, the
charging and discharging current of the implemented
oscillator capacitor are internally trimmed. The ratio of
controlled charge to discharge current is adjusted to
reach a maximum duty cycle limitation of D
Once the Soft Start period is over and when the IC goes
into normal operating mode, the switching frequency of
the clock is varied by the control signal from the Soft
Start block. Then the switching frequency is varied in
range of 65KHz ± 2.6KHz at period of 4ms.
3.5.2
The output of the oscillator block provides continuous
pulse to the PWM-Latch which turns on/off the
integrated CoolMOS
reset by the PWM comparator, the Soft Start
comparator or the Current -Limit comparator. When it is
in reset mode, the output of the driver is shut down
immediately.
Comparator
Comparator
Soft Start
Limiting
Current
PWM
Soft Start
Frequency
Duty Cycle
Oscillator
Block
Jitter
Clock
max
PWM Section
Oscillator
PWM-Latch FF1
PWM Section Block
®
0.75
. After the PWM-Latch is set, it is
Functional Description
G8
1
R
S
CoolSET
FF1
ICE3BR1065J
Q
PWM Section
Gate Driver
28 Dec 2011
CoolMOS
G9
&
Gate
max
®
=0.75.
-F3R
®