NCP1654BD200R2G ON Semiconductor, NCP1654BD200R2G Datasheet - Page 16

• Manufacturer Part Number: NCP1654BD200R2G
• Description: IC PFC CCM 200KHZ 8-SOIC
• Manufacturer: ON Semiconductor

Specifications of NCP1654BD200R2G

• Mode: Continuous Conduction (CCM)
• Frequency - Switching: 200kHz
• Current - Startup: 75µA
• Voltage - Supply: 10.5 V ~ 20 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The variable V
Follower Boost
pre−converter output voltage stabilizes at a level that varies
linearly versus the ac line amplitude. This technique aims
at reducing the gap between the output and input voltages
to optimize the boost efficiency and minimize the cost of
the PFC stage (refer to MC33260 data sheet for more
details at
V
where
V
DV
V
It is illustrated in Figure 39.
Follower Boost Benefits
reduce the output voltage V
voltage V
Because of the step−up characteristics of boost converter,
control
CONTROL(max)
CONTROL(min)
Input and output power (P
The “Follower Boost” is an operation mode where the
The NCP1654 operates in follower boost mode when
The follower boost circuit offers and opportunity to
CONTROL
Figure 39. Follower Boost Characteristics
is constant, i.e. V
ac
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V
V
P
is lower or the power demand P
out
in
out
is the gap between V
ac
.
(Traditional Boost)
is the maximum control voltage.
stands for the rms input voltage.
V
control
out
in
(Follower Boost)
out
P
T
P
T
P
+ h
V
and P
raises to its maximum value
in
out
out
out
(V
(V
whenever the rms input
+
).
2pR
+ h P
+ h
+ h
control
control
out
V
Z
ac
) are derived in (Equation 15) when the circuit efficiency η is obtained or assumed.
in
CS
CONTROL(max)
2pR
2pR
2
* V
in
* V
@ DV
2 R
+
+ h
CS
CS
2pR
M
CONTROL(min)
CONTROL(min)
out
V
V
2 R
@ (V
@ DV
CONTROL
R
out
out
2pR
SENSE
Time
Time
CS
M
is higher.
R
CONTROL(max)
CONTROL
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@ (V
SENSE
CS
V
and
@ (V
out
@ V
control
2 R
)V
)V
K
K
2 R
REF
control
BO
BO
ac
ac
16
@ V
M
* V
R
M
2 R
@ V
R
REF
SENSE
* V
V
(Equation 17) and (Equation 18) by replace V
V
(Equation 15), for a constant load or power demand the
output voltage V
rms input voltage V
becomes lower when the rms input voltage V
lower. On the other hand, the output voltage V
lower when the load or power demand becomes higher.
the output voltage V
voltage V
operation. As a result, the on time t
of on time makes the loss of the inductor and power
MOSFET smaller. Hence, it allows cheaper cost in the
inductor and power MOSFET or allows the circuit
components to operate at a lower stress condition in most
of the time.
Reference Section
±2% accurate over the temperature range (the typical value
is 2.5 V). V
V
response, Overvoltage (OVP), brown out (BO), and
Undervoltage protections (UVP).
Output Feedback
V
Figure 38. V
* V
SENSE
M
CONTROL(min)
CONTROL(max)
CONTROL(max)
REF
fb
ac
The internal reference voltage (V
The output voltage V
R
@
CONTROL(min)
SENSE
pin via the resistor divider (R
CONTROL(min)
P
V
V
also serves to build the thresholds of the fast transient
V
out
out
ac
out
K
in
V
K
BO
out
even though V
BO
REF
out
) @ V
K
BO
is regulated as described in (Equation 19).
. Re−formulate (Equation 16) to become
. If V
) @ V
V
out
) @ V
is the reference used for the regulation.
out
REF
out
of the converter is proportional to the
ac
REF
+ V
REF
@ V
. It means the output voltage V
will always be higher than the input
out
control
@ V
ac
@ V
REF
out
of the PFC circuits is sensed at
ac
ac
R
is reduced in follower boost
fbU
is constant based on
fbL
R
) R
1
fbL
REF
is reduced. Reduction
and R
fbL
) is trimmed to be
fbU
) as shown in
out
ac
control
becomes
becomes
(eq. 15)
(eq. 16)
(eq. 17)
(eq. 18)
(eq. 19)
by
out