NCP1605ADR2G ON Semiconductor, NCP1605ADR2G Datasheet - Page 23

• Manufacturer Part Number: NCP1605ADR2G
• Description: IC PFC CONTROLLER CCM/DCM 16SOIC
• Manufacturer: ON Semiconductor

Specifications of NCP1605ADR2G

• Mode: Continuous Conduction (CCM), Discontinuous Conduction (DCM)
• Frequency - Switching: 250kHz
• Current - Startup: 12mA
• Voltage - Supply: 10 V ~ 20 V
• Operating Temperature: 0°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Switching Frequency: 250 KHz
• Maximum Power Dissipation: 550 mW
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Overvoltage Protection
Overvoltage Protection (OVP) and the feedback, the
up−graded safety level as it protects the PFC stage even if
there is a failure of one of the two feedback arrangements.
possible as portrayed by Figure 61. The regulation and
OVP blocks having the same reference voltage, the
resistance ratio Rout2 over Rout3 adjusts the OVP
threshold. More specifically,
following constraint: (R
voltage exceeds the OVP level, the power switch is turned
off to stop the power delivery.
circuit” is “informed” when there is an OVP condition, not
to over−dimension V
OVP sequence would be viewed as a dead−time phase by
the circuit and V
compensate it (refer to Figure 56).
While PFC circuits often use one single pin for both the
The double feedback configuration offers some
However, if wished, one single feedback arrangement is
The bulk regulation voltage is:
The OVP level is:
The ratio OVP level over regulation level is:
For instance, (V
As soon and as long as the circuit detects that the output
Remark: Like in the NCP1601, the “V
3. Place a resistor R
Figure 61. Configuration with One Feedback
Pin 6 to ease the circuit detection by creating
some over−riding at the turn on instant. R
should be selected in the range of 3 times R
For instance, if R
can be used for R
Network for Both OVP and Regulation
R
R
R
V ovp +
V out +
out1
out3
out2
R out1 ) R out2 ) R out3
R out1 ) R out2 ) R out3
TON
V ovp
V out
OVP
TON
R out2 ) R out3
FB
would inappropriately increase to
out3
ZCD
DRV
DRV
+ 1 )
= 105% * V
in that conditions. Otherwise, an
Vout (bulk voltage)
R out2
= 5% * R
.
is 6.2 kW, a 22 kW resistor
between the drive pin and
R out3
R out2
1
2
3
4 13
5
6
7
8
16
15
14
12
10
11
9
out2
out
).
@ V ref
TON
@ V ref
) leads to the
OVP
HV
processing
DRV
http://onsemi.com
ZCD
.
23
− One for regulation applied to Pin 4.
− Another one for the OVP function.
− Incorrect feeding of the circuit (“UVLO” high when
− Excessive die temperature detected by the thermal
− Undervoltage Protection
NCP1605(A)
undervoltage
NCP1605(A) configuration allows the implementation of
two separate feedback networks (see Figure 62):
PfcOK / REF5V Signal
downstream converter. The signal “pfcOK/REF5V is high
(5 V) when the PFC stage is in normal operation (its output
voltage is stabilized at the nominal level) and low
otherwise.
More specifically, “pfcOK/REF5V” is low:
•
•
The
During the PFC stage startup, that is, as long as the
output voltage has not yet stabilized at the right level.
The startup phase is detected by the latch “L
block diagram. “L
that its output (“STUP”) is high when the circuit enters
an active phase. The latch is reset when the error
amplifier stops charging its output capacitor, that is,
when the output voltage of the PFC stage has reached its
desired regulation level. At that moment, “STUP” falls
down to indicate the end of the startup phase.
In case of a condition preventing the circuit from
operating properly, i.e., during the V
high voltage startup current source, in a Brown−out
case or when one of the following major faults turns
off the circuit:
R
R
V
shutdown.
out1
out2
CC
Figure 62. Configuration with Two Separate
<V
NCP1605(A)
CC
OFF, V
dedicates
FB
and
Feedback Networks
Vout (bulk voltage)
STUP
CC
OFF equating 9 V typically).
overvoltage
” is set during each “off” phase so
can
1
2
3
4 13
5
6
7
8
one
16
15
14
12
10
11
9
communicate
specific pin for the
OVP
protections.
HV
CC
charge by the
STUP
R
R
with
ovp1
ovp2
” of the
The
the