NCP1607BDR2G ON Semiconductor, NCP1607BDR2G Datasheet - Page 11

• Manufacturer Part Number: NCP1607BDR2G
• Description: IC PFC CONTROLLER CRM 8SOIC
• Manufacturer: ON Semiconductor

Specifications of NCP1607BDR2G

• Mode: Critical Conduction (CRM)
• Current - Startup: 23.5µA
• Voltage - Supply: 9.5 V ~ 20 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Switching Frequency: 70 KHz
• Maximum Power Dissipation: 450 mW
• Maximum Operating Temperature: + 125 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

linearly to its peak value. When the switch opens, the
inductor current linearly decreases to zero. At this point,
the drain voltage of the switch (V
and begins to drop. If the next switching cycle does not
start, then the voltage will ring with a dampened frequency
around V
in AND8123), leads to the result that good power factor
correction in CRM operation is achieved when the on time
is constant across an ac cycle and is equal to:
illustrated in Figure 24. The off time varies based on the
instantaneous line voltage, but the on time is kept constant.
This naturally causes the peak inductor current (I
follow the ac line voltage.
this constant on time CRM control in a cost effective and
robust solution. The device incorporates an accurate
regulation circuit, a low power startup circuit, and
advanced protection features.
EA sets the FB level. If the output voltage is too low, then
the FB level will drop and the EA will cause the control
voltage to increase. This increases the on time of the driver,
which increases the power delivered and brings the output
back into regulation. Alternatively, if the output voltage
(and hence FB voltage) is too high, then the control level
decreases and the driver on times are shortened. In this way,
the circuit regulates the output voltage (V
V
R
R
OUT
When the switch is closed, the inductor current increases
A simple plot of this switching over an ac line cycle is
The NCP1607 represents an ideal method to implement
A resistor divider from the boost output to the input of the
OUT2
OUT1
V
OUT
portion that is applied to FB through the resistor
in
. A simple derivation of equations (such as found
C
COMP
Control
t on +
FB
2 @ P
R
h @ Vac
FB
Figure 25. Error Amplifier and On Time Regulation Circuits
OUT
@ L
d
2
) is essentially floating
+
V
CONTROL
EA
V
+
−
REF
OUT
) so that the
L(pk)
http://onsemi.com
(eq. 1)
t
on
) to
t
on(MAX)
t
PWM
11
ERROR AMPLIFIER REGULATION
voltage based on its built in error amplifier (EA). The error
amplifier ’s negative terminal is pinned out to FB, the
positive terminal is tied to a 2.5 V ± 1.6% reference, and the
output is pinned out to Control (Figure 25).
divider R
(2.5 V). The output voltage is set using Equation 2:
Where R
R
Figure 24. Inductor Waveform During CRM Operation
EQ
The NCP1607 is configured to regulate the boost output
MOSFET
Slope +
is calculated using Equation 3:
V
PWM BLOCK
EAL
V
EQ
I
OUT1
IN(pk)
IN(pk)
I
L(pk)
OFF
ON
is the parallel combination of R
I
V
CHARGE
and R
OUT
Ct
V
R
CONTROL
+ V
EQ
OUT2
+
REF
R
R
is equal to the internal reference
OUT2
OUT2
@
R
) R
@ R
OUT1
V
EAH
R
FB
FB
EQ
) R
EQ
V
IN
OUT2
(t)
I
L
(t)
I
IN
(t)
and R
(eq. 2)
(eq. 3)
FB
.