NCP1650EVB ON Semiconductor, NCP1650EVB Datasheet - Page 3

• Manufacturer Part Number: NCP1650EVB
• Description: Power Management IC Development Tools EVALUATION BOARD
• Manufacturer: ON Semiconductor
• Type: AC/DC Convertersr

Specifications of NCP1650EVB

• Product: Evaluation Boards
• Tool Is For Evaluation Of: NCP1650
• Input Voltage: 85 V to 265 V
• Output Voltage: 400 V

Voltage Regulation Loop
level by the resistive divider consisting of R27, R28 and
R29. The output voltage of this divider is sensed by the
non-inverting input of the error amplifier and compared to
the internal 4.0 V reference.
the voltage error signal will dominate the loop and be fed
through the OR’ing network to provide one of the inputs to
the reference multiplier. The other reference multiplier input
is the divided down rectified AC input signal.
accurate replica of the input AC signal. The current shaping
network compares the average current from the current
sense amplifier to the reference voltage and forces this
current to follow the AC reference voltage. The current out
of the current sense amplifier is filtered at a frequency that
is less than the switching frequency, but greater than the
rectified line frequency.
filter it to a DC level.
Power Regulation Loop
current (from the current sense amplifier) and the AC
rectified input voltage, to generate a signal that represents
the input power of the unit. This signal is filtered to a
frequency of less than the line frequency, so that it’s output
is a DC level.
The output voltage is sensed and reduced to the reference
Assuming that the unit in not in a power limit condition,
The output of this multiplier is a haversine signal that is an
This current is fed into the output filter capacitor(s) that
The power multiplier generates the product of the input
ON
Semiconductor
Q3
Gnd
R20
R22
R23
R21
Shutdown
C23
+
0 V/5 V
C25
http://onsemi.com
R27
R28
R29
AND8106/D
D7
3
maximum power limit of the circuit, the output of the power
multiplier will reach 2.5 V and the output of the power error
amplifier will go to some level above ground. This signal
will then override the signal from the voltage error amplifier
(labeled “error amp” on the schematic), and will dominate
the OR’ing network.
signal out of the reference multiplier, and determines the
input current to the power converter. It should be noted that
as this is a boost converter, the power limit circuit will only
fold back the output voltage until it reaches the level of the
peak line voltage. At this point the converter will shut down,
but the input voltage will continue to charge the output
capacitors through the rectifier.
Shutdown Circuit
power converter and put the NCP1650 into a low power
shutdown mode. To activate this circuit, apply 5.0 V to the
red test point, with the black jack being “ground”. Be aware
that the black jack is actually hot as it is connected to the
output of the input bridge rectifiers. An isolated 5.0 V
supply should be used.
open, as there is enough resistance built in to the circuit to
keep the transistor (Q2) in it’s off state.
PCB
ON Semiconductor website under the name NCP650- PCB1.
If the load is increased to a level that exceeds the
This signal then determines the level of the reference
The shutdown circuit will inhibit the operation of the
If this circuit is not being used, the terminals can be left
The printed circuit board Gerber files are located on the
Q1
L1
C21
R4
R6
R5
D2
D4
D1
D3
L3
L2
C20