ICE3AR10080CJZ Datasheet, PDF (15/33 Pages) Infineon Technologies AG – Off-Line SMPS Current Mode Controller with integrated 800V CoolMOS® and Startup cell (brownout & CCM) in DIP-7

CoolSET^®-F3R80
ICE3AR10080CJZ
Functional Description
Similarly, the same concept of propagation delay
compensation is also implemented in burst mode with
reduced level, V_{csth_burst} (Figure 18). With this
implementation, the entry and exit burst mode power
can be close between low line and high line input
voltage.
3.7
Control Unit
CS
V_{csth_burst} C12
Burst detect
and adjust
G6 & FF1
Current
Limiting
Internal
Bias
The Control Unit contains the functions for Active Burst
Mode, Auto Restart Mode and Latch Mode. The Active
Burst Mode, Latch Mode and the Auto Restart Mode
both have internal blanking time. With the blanking
time, the IC avoids entering into those two modes
accidentally. Those buffer time is very useful for the
application which works in short duration of peak power
occasionally.
V_{FB_burst C5}
FBB
C13
4.0V
R_sel
3.5V
C6a
20 ms
Blanking Time
Active Burst
Mode
3.7.1
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. ICE3ARxx80CJZ 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. ICE3ARxx80CJZ
provides a more flexible level which can be selected
externally.
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.
ICE3ARxx80CJZ 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.
ICE3ARxx80CJZ reduces the swing to 0.3V (from
0.5V). Therefore, it would have around 40%
improvement for the output ripple.
C6b
3.2V
&
G11
Control Unit
Figure 23 Active Burst Mode
The Active Burst Mode is located in the Control Unit.
Figure 23 shows the related components.
3.7.1.1 Selectable burst entry level
The burst mode entry level can be selected by
changing the different Resistor R_sel at FBB pin. There
are 3 levels to be selected with different resistor which
are targeted for 15%, 10% and 5% of the maximum
input power. At the same time, the exit burst level are
targeted to 27%, 20% and 11% of the maximum power
accordingly. The below table is the control logic for the
entry and exit level with the FBB voltage.
Level
V_FBB
1 V_FBB< V_ref1 (1.8V)
2 V_ref1 (1.8V) <V_FBB<V_ref2 (4.0V)
3 V_FBB > V_ref2 (4.0V)
R_sel
< 405kW
685kW ~ 900kW
> 1530kW
Level
1
2
3
Entry level
Exit level
% of P_{in_max}
5%
V_{FB_burst}
1.29V
% of P_{in_max} V_{csth_burst}
11%
0.21V
10%
1.61V
20%
0.29V
15%
1.84V
27%
0.34V
Version 2.0
15
11 Jan 2012