CoolSET™-F2
ICE2A165/265/365
ICE2A180/280
Functional Description
ca. t = 130ns
VG ate
Overload & Open loop/normal load
5µs Blanking
FB
4.8V
Failure
Detection
5V
t
SoftS
5.3V
t
Figure 17 Gate Rising Slope
Soft-Start Phase
3.8
Protection Unit (Auto Restart Mode)
An overload, open loop and overvoltage detection is
integrated within the Protection Unit. These three
failure modes are latched by an Error-Latch. Additional
thermal shutdown is latched by the Error-Latch. In case
of those failure modes the Error-Latch is set after a
blanking time of 5µs and the CoolMOS™ is shut down.
That blanking prevents the Error-Latch from distortions
caused by spikes during operation mode.
t
TBurst1
Driver
TRestart
t
3.8.1
Overload & Open loop with normal
load
VCC
13.5V
Figure 18 shows the Auto Restart Mode in case of
overload or open loop with normal load. The detection
of open loop or overload is provided by the Comparator
C3, C4 and the AND-gate G2 (see Figure19). The
detection is activated by C4 when the voltage at pin
SoftS exceeds 5.3V. Till this time the IC operates in the
Soft-Start Phase. After this phase the comparator C3
can set the Error-Latch in case of open loop or overload
which leads the feedback voltage VFB to exceed the
threshold of 4.8V. After latching VCC decreases till
8.5V and inactivates the IC. At this time the external
Soft-Start capacitor is discharged by the internal
transistor T1 due to Power Down Reset. When the IC
is inactive VVCC increases till VCCon = 13.5V by charging
the Capacitor CVCC by means of the Start-Up Resistor
8.5V
t
Figure 18 Auto Restart Mode
6.5V
Power Up Reset
RSoft-Start
SoftS
RStart-Up. Then the Error-Latch is reset by Power Up
Reset and the external Soft-Start capacitor CSoft-Start is
charged by the internal pullup resistor RSoft-Start . During
the Soft-Start Phase which ends when the voltage at
pin SoftS exceeds 5.3V the detection of overload and
open loop by C3 and G2 is inactive. In this way the Start
Up Phase is not detected as an overload.
CSoft-Start
C4
Error-Latch
5.3V
G 2
T1
4.8V
C3
FB
R FB
6.5V
Figure 19 FB-Detection
Datasheet
12
September 2001
INFINEON [ Infineon ]
