ICE3BR1065J_11 INFINEON [Infineon Technologies AG], ICE3BR1065J_11 Datasheet - Page 14

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

3.6.1
Figure 18
Whenever the integrated CoolMOS
leading edge spike is generated due to the primary-
side capacitances and reverse recovery time of the
secondary-side rectifier. This spike can cause the gate
drive to switch off unintentionally. In order to avoid a
premature termination of the switching pulse, this spike
is blanked out with a time constant of t
3.6.2
In case of over-current detection, there is always
propagation delay to switch off the integrated
CoolMOS
induced to the delay, which depends on the ratio of dI/
dt of the peak current (see Figure 19).
Figure 19
The overshoot of Signal2 is larger than of Signal1 due
to the steeper rising waveform. This change in the
slope depends on the AC input voltage. Propagation
Delay Compensation is integrated to reduce the
overshoot due to dI/dt of the rising primary current.
Thus the propagation delay time between exceeding
the current sense threshold V
of the integrated CoolMOS
temperature within a wide range. Current Limiting is
then very accurate.
Version 2.0
I
I
I
V
peak2
peak1
Limit
csth
I
V
Sense
Sense
®
. An overshoot of the peak current I
Propagation Delay Compensation
Leading Edge Blanking
Leading Edge Blanking
Current Limiting
I
Overshoot2
Signal2
t
LEB
= 220ns
®
csth
is compensated over
and the switching off
Signal1
®
t
is switched on, a
Propagation Delay
LEB
= 220ns.
I
Overshoot1
t
peak
t
is
14
For example, I
sense threshold is set to a static voltage level V
without Propagation Delay Compensation. A current
ramp of dI/dt = 0.4A/µs, or dV
propagation delay time of t
to an I
delay compensation, the overshoot is only around 2%
(see Figure 20).
Figure 20
The Propagation Delay Compensation is realized by
means of a dynamic threshold voltage V
21). In case of a steeper slope the switch off of the
driver is earlier to compensate the delay.
Figure 21
V
V
OSC
csth
1,25
1,15
1,05
0,95
V
1,3
1,2
1,1
0,9
V
1
Sense
peak
0
max. Duty Cycle
overshoot of 14.4%. With the propagation
0,2
Overcurrent Shutdown
Signal1
Dynamic Voltage Threshold V
peak
0,4
= 0.5A with R
0,6
with compensation
0,8
Functional Description
1
dV
off time
Propagation Delay
dt
Propagation Delay
Sense
Sense
1,2
CoolSET
without compensation
Sense
ICE3BR1065J
1,4
/dt = 0.8V/µs, and a
Signal2
= 2. The current
1,6
csth
28 Dec 2011
=180ns leads
1,8
(see Figure
csth
®
2
-F3R
csth
t
t

V
s
=1V