NCP1631DR2G ON Semiconductor, NCP1631DR2G Datasheet - Page 14

• Manufacturer Part Number: NCP1631DR2G
• Description: IC CTLR PFC INTERLEAVED 16SOIC
• Manufacturer: ON Semiconductor

Specifications of NCP1631DR2G

• Mode: Critical Conduction (CRM), Discontinuous Conduction (DCM)
• Frequency - Switching: 130kHz
• Current - Startup: 100µA
• Voltage - Supply: 10 V ~ 15 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

depending on the presence or absence of an effective
in−rush limiting circuitry. If the MOSFET turns on during
this severe transient, it may be over−stressed and finally
damaged. That is why, the NCP1631 permanently monitors
the input current and delays the MOSFET turn on until the
in−rush current has vanished. This is the function of the I
comparison to the I
I
high and prevents the PWM latches from setting (see block
diagram). Hence, the two drivers cannot turn high and the
MOSFETs cannot switch on. This is to guarantee that the
MOSFETs remain off as long as if the input current exceeds
10% of its maximum value. This feature protects the
Over−Voltage Protection
Over−Voltage Protection (OVP) and the feed−back, the
NCP1631 dedicates one specific pin for the under−voltage
and over−voltage protections. The NCP1631 configuration
CS
While PFC circuits often use one single pin for both the
exceeds I
Filter
EMI
The pin voltage
is maintained
to 0 V
Figure 14. Configuration with One Feed−back
R
V
Network for Both OVP and Regulation
in−rush
IN
OCP
I
CS
Rout1
Rout3
Rout2
C
CS
IN
Vout (bulk voltage)
in−rush
, the comparator output (“In−rush”) is
R
9
CS
I
IN
The CS block performs the over−current protection and the in−rush current detection.
Negative clamp
threshold (14 mA typical). When
I
CS
OVP
FB
Curr e nt
1
3
4
5
6
7
Mirror
8
2
I
IN
I
CS
Figure 13. Current Sense Block
(I
I
I
CS
in−rush
ILIM1
16
15
14
13
12
11
10
9
is proportional to the coil current)
= 210 mA
http://onsemi.com
= 14 mA
CS
I
I
CS
CS
14
MOSFETs from the possible excessive stress it could suffer
from if it was allowed to turn on while a huge current
flowed through the coil as it can be the case at start−up or
during an over−load transient.
high) is in the range of few ms.
disables this protection to avoid that the current produced
by one phase and sensed by the circuit prevents the other
branch from operating. Practically, some logic grounds the
In−rush protection output when it detects the presence of
current cycles with a zero current detection signal provided
by the auxiliary winding (Figure 13).
allows the implementation of two separate feed−back
networks (see Figure 15):
The propagation delay (I
However when the circuit starts to operate, the NCP1631
In−rush
1. One for regulation applied to pin 2.
2. Another one for the OVP function (pin 8).
OC P
Figure 15. Configuration with Two
Separate Feed−back Networks
Rovp2
Rovp1
Q
Q
ZCD1
ZCD2
(from ZCD
block)
DRV 1
DRV 2
Vout (bulk voltage)
Rout2
Rout1
OVP
CS
FB
V
DRV 1
aux1
< I
M
L
1
3
4
5
6
7
1
8
2
in−rush
1
V
DRV 2
D
aux2
) to (drive outputs
1
M
2
L
2
C
D
BULK
2
16
15
14
13
12
11
10
9
V
OUT