MC33260DG ON Semiconductor, MC33260DG Datasheet - Page 15

• Manufacturer Part Number: MC33260DG
• Description: IC PFC CONTROLLER DCM 8SOIC
• Manufacturer: ON Semiconductor
• Series: GreenLine™r

Specifications of MC33260DG

• Mode: Discontinuous Conduction (DCM)
• Current - Startup: 100µA
• Voltage - Supply: 11 V ~ 16 V
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Maximum Operating Temperature: + 105 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Frequency - Switching: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

dictates the on- -time necessary to deliver the required power:
where:
Follower Boost equation:
voltage to the ac line amplitude at a given input power.
Figures 34 and 35. In particular, Figure 35 illustrates how
the output voltage converges to a stable equilibrium level.
First, at a given ac line voltage, the on- -time is dictated by the
power demand. Then, the follower boost characteristic
makes correspond one output voltage level to this on- -time.
Combining these two laws, it appears that the power level
forces the output voltage.
On the other hand, the boost topology has its own rule that
Combining the two equations, one can obtain the
Consequently, a linear dependency links the output
The behavior of the output voltage is depicted in
One can notice that the system is fully stable:
V
L
P
 If an output voltage increase makes it move away from
 In the same way, if the output voltage decreases, more
in
p
pk
V
its equilibrium value, the on- -time will immediately
diminish according to the follower boost law. This will
result in a delivered power decrease. Consequently,
the supplied power being too low, the output voltage
will decrease back,
power will be transferred and then the output voltage
will increase back.
o
is the inductor value,
is the input power.
Figure 34. Follower Boost Characteristics
is the peak ac line voltage,
V o =
P
in
R o
(V
2
ac
The Regulation Block is Active
)max
×
t on =

t
on
K osc × L p × P in
4 × L p × P
V
ac
V 2
C
pk
pin3
(V
ac
Pin Numbers are Relevant to the PDIP- -8 Version
)min
in
t
on--time
on
= k/V
Output Voltage
Input Power
× V
o
2
pk
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15
Mode Selection
oscillator capacitor value. As shown in Figure 35, the output
voltage first has an increasing linear characteristic versus the
ac line magnitude and then is clamped down to the
regulation value. In the traditional mode, the linear area
must be rejected. This is achieved by dimensioning the
oscillator capacitor so that the boost can deliver the
maximum power while the output voltage equals its
regulation level and this, whatever the given input voltage.
Practically, that means that whatever the power and input
voltage conditions are, the follower boost would generate
output voltages values higher than the regulation level, if
there was no regulation block.
level:
equation can be simplified as follows:
be chosen so that the wished characteristics are obtained.
capacitor enables the mode selection.
C
The operation mode is simply selected by adjusting the
In other words, if (V

Consequently,
T
Using I
In the Follower Boost case, the oscillator capacitor must
Consequently, the simple choice of the oscillator
V o
C T ≥ --C int +
(P
V
≥ --C
o
in

regL
)min
Figure 35. Follower Boost Output Voltage
int
regL
≤
+
V
acLL
R o
(regulation block current reference), this
2
4 × K osc × L p ×
×
4 × K osc × L p ×
Regulation Block is Active
P

in
V
o
ac
)
K osc × L p ×
regL
is the low output regulation
R 2 o × V 2
(P
C
in
T
)max

V 2
P in
+ C
pk

P

pk
non usable area

in
max ×
int
P

V
in
acHL
max × I 2

V
max
o
= V

V o
pk
× V
regL

V
2
regL
ac
pk