ncp1601a ON Semiconductor, ncp1601a Datasheet - Page 11

• Manufacturer Part Number: ncp1601a
• Description: Compact Fixed Frequency Discontinuous Or Critical Conduction Voltage Mode Power Factor Correction Controller
• Manufacturer: ON Semiconductor

V
from (eq.1)−(eq.5)
voltage V
bandwidth of V
inserting an external capacitor C
(Pin 2) in Figure 28. The internal 300 kW resistor and the
capacitor C
bandwidth f
limit the bandwidth below 20 Hz to achieve power factor
correction. Typical value of C
60 Hz line frequency, the input impedance Z
varying or roughly constant. Then, the power factor
correction is achieved in DCM and CRM.
Maximum Power
(eq.8) when the circuit efficiency h is obtained or assumed.
The variable V
of output power, input power, or input impedance. The
maximum value of the control voltage V
(i.e., V
power resistor R
and restricted to have a maximum ±10% variation
(i.e., 9.5 kW ≤ R
power in an application.
control
It is noted that V
In summary, the input impedance Z
Control voltage V
If the bandwidth of V
Input and output power (P
From (eq.8), control voltage V
Regulation Block
V
96%
reg
control(max)
Figure 30. V
(i.e., V
P in +
P out + h P in +
I
ref
out
control
control
I
ref
Z in +
C control u
which is a slowly varying signal. The
ac
V ton + V control
ton
power
V ac 2
power
Z in
control
stands for the RMS input voltage.
= 1.05 V). A parameter called maximum
I
in (eq.7). It is generally recommended to
≥ V
FB
create a low−pass filter which has a
ton
control
V in
≤ 11.5 kW) for defining the maximum
control
I in
+
(10.5 kW typical) is defined in (eq.9)
control
is always greater than or equal to
control
V ac 2 C ramp V control
can be additionally limited by
+
hV ac 2 C ramp V control
300k
2p300kW f control
V
Low−Pass Filtering
C ramp V control
).
control
comes from the PFC output
control
in
is much less than the 50 or
2LI ch
2 L I ch
control
and P
control
2LI ch
2
1
C
in
is 0.1 mF.
control
controls the amount
in (eq.6) is obtained
out
to the V
for CRM
) are derived in
V
Processing
Circuit
control
control
NCP1601A, NCP1601B
in
control
is 1.05 V
is slowly
(eq.5b)
(eq.8a)
(eq.8b)
http://onsemi.com
(eq.6)
(eq.7)
pin
11
(P
maximum input power P
The suffix ac stands for RMS value.
Output Feedback
feedback current I
device. The FB pin voltage V
referring to Figure 11. It is much lower than V
typically 400 V. Therefore, V
where R
FB pin (Pin 1) and the output voltage referring to Figure 2.
voltage V
regulation,
Overvoltage Protection (OVP).
Output Voltage Regulation
V
typical) as shown in Figure 31.
output of the regulation block is as high as V
(1.05 V typical) that gives the maximum value on V
a result, it gives the maximum MOSFET on time and V
increases. When I
V that gives no MOSFET on time and V
a result, the output voltage V
range between 96% and 100% of the nominal value of R
× I
is inversely proportional to V
condition V
R power +
out
It means that the maximum input and output power
in(max)
The maximum input current I
The output voltage V
Then, the feedback current I
Feedback current I
When I
Based on (eq.8) for a particular power level, the V
ref
I ac(max) +
, is regulated with a reference current (I
.
FB
and P
P in(max) +
P out(max) +
FB
out
is the feedback resistor connected between the
V control(max)
control
1.05 V
is lower than 96% of I
Undervoltage
Figure 31. Regulation Block
and will be used in the output voltage
I FB +
out(max)
P in(max)
I ch
FB
FB
V ac
is lower. It means that I
V
is higher than I
flowing into the FB pin (Pin 1) of the
V ac 2 C ramp R power
V out * V FB1
reg
) are limited to ±10% variation.
FB
96%
hV ac 2 C ramp R power
out
, which presents output voltage
in(max)
+
+
R FB
of the PFC circuit is sensed as a
I
ref
V acC ramp R power
100 mA
1.05 V
2 L
FB1
FB1
out
Protection
2 L
is also derived in (eq.11).
ac
FB
I
is typically less than 5 V
ref
is generally neglected.
2
is regulated around the
ref
. Hence, in high V
ac(max)
ref
[
2 L
represents the output
+ 10.5 kW
, the V
, the V
I
V out
R FB
FB
out
reg
to deliver the
(UVP),
reg
decreases. As
FB
ref
which is the
out
becomes 0
control(max)
= 203 mA
or output
which is
(eq.10a)
(eq.10b)
(eq.12)
(eq.11)
ton
(eq.9)
control
. As
and
out
FB
ac