Forced Quasi Resonant ZVS flyback controller
Functional Description
VBULK
VAC = 85 ... 264
CBulk
Vrms
RHV = 100kW
CVCC
VCC
HV
HV Startup-
cell
Startup-Cell
Driver
Closed/Open
D1
Brown-in &
Brown-out
Protection
QM
&
I
I
HVBI = 1.15 mA
HVBO = 0.442mA
PWM
Logic
RM
VCC Brown-in
Protection
Power Supply
Management
VVCCBI = 9.1 V
UVLO
VVCCon = 20.5 V
HW Reset
VVCCoffx = 7.2 V / 9.6 V
Figure 5
High voltage brown-in sensing and VCC startup at HV pin
4.1.3
Brown-out protection
In case of brown-out (see Chapter 4.3.5), the IC stops gate driver switching. Brown-out detection is also performed via the
HV pin as for brown-in detection. Here an under-voltage detection of the bulk voltage VBulk is provided to support brown-out
protection. The measured current IHV is compared with the bulk under-voltage detection threshold IHVBO = 0.443 mA.
4.1.4
During burst mode operation
After the control IC enters quiet burst mode, the IC enters repeatedly a sleep mode, in which the IC current consumption is
reduced to IVCCquBM2 = 460 µA. Waking up from and entering this sleep mode (pause) is controlled by the feedback voltage at
MFIO pin VMFIO via the internal comparators C5 and C6 (see Figure 6 and Chapter 4.2.910).
Data Sheet
9
Revision 2.0
2020-08-20
INFINEON [ Infineon ]
