NCP1606BOOSTGEVB ON Semiconductor, NCP1606BOOSTGEVB Datasheet - Page 17

• Manufacturer Part Number: NCP1606BOOSTGEVB
• Description: EVAL BOARD FOR NCP1606BOOSTG
• Manufacturer: ON Semiconductor

Specifications of NCP1606BOOSTGEVB

• Design Resources: NCP1606BOOST EVB BOM NCP1606BOOSTGEVB Gerber Files NCP1606BOOST EVB Schematic
• Main Purpose: AC/DC, Primary and Secondary Side with PFC
• Outputs And Type: 1, Isolated
• Power - Output: 100W
• Voltage - Output: 400V
• Current - Output: 250mA
• Voltage - Input: 88 ~ 264VAC
• Regulator Topology: Boost
• Frequency - Switching: 250kHz
• Board Type: Fully Populated
• Utilized Ic / Part: NCP1606
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: NCP1606BOOSTG
• Other names: NCP1606BOOSTGEVBOS

STATIC OVERVOLTAGE PROTECTION
that the error amplifier output reaches its minimum level
(i.e. Control = V
current and maintain the OVP fault. Therefore, to avoid any
discontinuity in the OVP disabling effect, the circuit
incorporates a comparator which detects when the lower
level of the error amplifier is reached. This event, called
“static OVP”, disables the output drives. Once the OVP
event is over, and the output voltage has dropped to normal,
then Control rises above the lower limit and the driver is
re−enabled (Figure 35).
NCP1606 Undervoltage Protection (UVP)
forced to roughly equate the peak line voltage. The
NCP1606 detects an undervoltage fault when this output
voltage is unusually low, such that the feedback voltage is
below V
output and error amplifier (EA) are disabled. The latter is
done so that the EA does not source a current which would
increase the FB voltage and prevent the UVP event from
being accurately detected. The UVP feature helps to
protect the application if something is wrong with the
power path to the bulk capacitor (i.e. the capacitor cannot
charge up) or if the controller cannot sense the bulk voltage
(i.e. the feedback loop is open).
For the above example, this leads to:
If the OVP condition lasts for a long time, it may happen
When the PFC stage is plugged in, the output voltage is
Dynamic OVP
Static OVP
Icontrol
Vcontrol
Vout(nom)
R
Vout
Drive
OUT2
IovpH
UVP
IovpL
V
V
EAH
EAL
Figure 35. OVP Timing Diagram
(300 mV typ). In an UVP fault, the drive
+
EAL
400 V * 2.5 V
). It would then not be able to sink any
2.5 V
@ 1.9 MW + 12.0 kW.
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17
sequence which ensures that undervoltage conditions are
always detected at startup. It accomplishes this by waiting
approximately 180 ms after V
enabling the error amplifier (Figure 36). During this wait
time, it looks to see if the feedback (FB) voltage is greater
than the UVP threshold. If not, then the controller enters a
UVP fault and leaves the error amplifier disabled.
However, if the FB pin voltage increases and exceeds the
UVP level, then the controller will start the application up
normally.
given by:
UVP threshold is 48 V. This corresponds to an input voltage
of approximately 34 Vac.
Overcurrent Protection (OCP)
and limits the driver on time if this current exceeds
V
0.5 V (typ) on the NCP1606B. Therefore, the maximum
peak current can be adjusted by changing R
to:
of switching noise falsely triggering the OCP limit. This
filter blanks out the first 250 ns (typical) of the current
sense signal. If additional filtering is necessary, a small RC
filter can be added between R
V
V
V
OUT(nom)
CS(limit)
Furthermore, the NCP1606 incorporates a novel startup
The voltage on the output which exits a UVP fault is
If R
A dedicated pin on the NCP1606 senses the peak current
An internal LEB filter (Figure 37) reduces the likelihood
CC(on)
CC(off)
Figure 36. The NCP1606’s Startup Sequence with
2.5 V
V
V
V
UVP
EAH
EAL
OUT1
V
. This level is 1.7 V (typ) on the NCP1606A and
OUT
Control
V
FB
UVP
V
= 1.9 MW and R
OUT
CC
(UVP)
and without a UVP Fault
+
R
I
peak
OUT1
UVP Fault is “Removed”
R
+
OUT2
UVP Wait
) R
OUT2
V
R
SENSE
CS(limit)
CC
SENSE
OUT2
= 12.0 kW, then the V
reaches V
and the CS pin.
@ 300 mV
SENSE
CC(on)
according
UVP Wait
(eq. 13)
(eq. 14)
before
OUT