ICE3AR1580VJZ Datasheet, PDF (21/43 Pages) Infineon Technologies AG – Of f -Line SMPS Cur rent Mode Cont rol ler wi th integrated 800V

CoolSET™ F3R80
ICE3AR1580VJZ
Functional Description
comparator C11, the counter will increase the counter by 1. Then it switches off the switch S1 and turns on the
switch S2. The voltage at BV pin will be discharged through a 500Ω resistor. When the voltage drops to 0.9V which
is sensed by comparator C3, the switch S2 will be turned off and the switch S1 will be turned on. Then the constant
current I_{chg_EB} will charge the CBK capacitor again. When the voltage at BV hits 4.5V which is sensed by comparator
C11, the counter will increase the count to 2. The process repeats until it reaches total count of 256 (Figure 24).
Then the counter will release a high output signal. When the AND gate G5 detects both high signals at the inputs, it
will activate the 30µs spike blanking circuit and finally the auto-restart mode will be activated.
Figure 24: Waveform at extended blanking time
For example, if C_BK=0.1µF, I_{chg_EB}=720µA_, R_OV2=15KΩ,
I_{chg_EB}’=I_{chg_EB}-(4.5V+0.9V)/(2*R_OV2)=540 µA
Extended blanking time = 256*(C_BK*(4.5V-0.9V)/ I_{chg_EB}’+ C_BK*500*ln(4.5/0.9)) = 192ms
Total blanking time = 20ms+192 = 212ms
where I_{chg_EB}’=net charging current to C_BK
Note: The above calculation does not include the effect of the input OVP circuit where there is extra biasing
current flowing from the input. That means the extended blanking time will be shortened with the line voltage
change if input OVP circuit is implemented.
3.7.2 Active Burst Mode (patented)
To increase the efficiency of the system at light load, the most effective way is to operate at burst mode. Starting from
CoolSET™™ F3, the IC has been employing the active burst mode and it can achieve the lowest standby power.
ICE3AR1580VJZ adopts the same concept with some more innovative improvements to the feature. It includes the
adjustable entry burst level, close power control between high line and low line and the smaller output ripple during
burst mode.
Most of the burst mode design in the market will provide a fixed entry burst mode level which is a ratio to the
maximum power of the design. ICE3AR1580VJZ provides a more flexible level which can be selected externally. The
provision also includes not entering burst mode.
Propagation delay is the major contributor for the power control variation for DCM flyback converter. It is proved to
be effective in the maximum power control. ICE3AR1580VJZ also apply the same concept in the burst mode.
Therefore, the entry and exit burst mode power is also finely controlled during burst mode.
The feedback control swing during burst mode will affect the output ripple voltage directly. ICE3AR1580VJZ
reduces the swing from 0.5V to 0.3V. Therefore, it would have around 40% improvement for the output ripple.
Data Sheet
21
V2.0, 2014-01-20