ICE3A1065 Datasheet, PDF(18/32 Page) Infineon Technologies AG – Off-Line SMPS Current Mode Controller with integrated 650V Startup Cell/ Depletion CoolMOS™

English

English German Russian Spanish Italian Polish Chinese Japanese Korean French Portuguese	Language :

ICE3A1065 Datasheet, PDF (18/32 Pages) Infineon Technologies AG – Off-Line SMPS Current Mode Controller with integrated 650V Startup Cell/ Depletion CoolMOS™

◁

Once the Auto Restart Mode is entered, the internal

Voltage Reference is switched off in order to reduce the

current consumption of the IC as much as possible. In

this mode, the average current consumption is only

300mA as the only working block is the Undervoltage

Lockout(UVLO) which controls the Startup Cell by

switching on/off at VVCCon/VVCCoff.

As there is no longer a self supply by the auxiliary

winding, VCC starts to drop. The UVLO switches on the

integrated Startup Cell when VCC falls below 8.5V. It

will continue to charge VCC up to 15V whereby it is

switched off again and the IC enters into the Start Up

Phase.

As long as all fault conditions have been removed, the

IC will automatically power up as usual with switching

cycle at the GATE output after Soft Start duration. Thus

the name Auto Restart Mode.

Other fault detections which are active in normal

operation is the sensing for Overload, Open Loop and

VCC undervoltage conditions. In the first 2 cases, FB

will rise above 4.8V which will be observed by C4. At

this time, S1 is released such that VSoftS can rise from

its earlier clamp voltage of 4.4V. If VSoftS exceeds 5.4V

which is observed by C3, Auto Restart Mode is entered

as both inputs of the gate G5 are high.

This charging of the Soft Start capacitor from 4.4V to

5.4V defines a blanking window which prevents the

system from entering into Auto Restart Mode un-

intentionally during large load jumps. In this event, FB

will rise close to 6.5V for a short duration before the

loop regulates with FB less than 4.8V. This is the same

blanking time window as for the Active Burst Mode and

can therefore be adjusted by the external CSoftS.

In the case of VCC undervoltage, ie. VCC falls below

8.5V, the IC will be turn off with the Startup Cell

charging VCC as described earlier in this section. Once

VCC is charged above 15V, the IC will start a new

startup cycle. The same procedure applies when the

system is under Short Optocoupler fault condition, as it

will lead to VCC undervoltage.

CoolSETâ¢-F3

Functional Description

Version 2.3

02 Apr 2013

▷