TEA1713T_11 NXP [NXP Semiconductors], TEA1713T_11 Datasheet - Page 18

• Manufacturer Part Number: TEA1713T_11
• Description: Resonant power supply control IC with PFC
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
TEA1713T
Product data sheet
7.7.7 PFC overcurrent regulation, OCR-PFC (pin SNSCURPFC)
7.7.8 PFC mains undervoltage protection/brownout protection, UVP-mains
7.7.9 PFC boost overvoltage protection, OVP-boost (pin SNSBOOST)
This is achieved by connecting a resistor R
pin SNSCURPFC and the current sense resistor R
source I
voltage is limited to the maximum PFC soft start clamp voltage, V
additional voltage across the charged capacitor results in a reduced peak current. After
start-up, the internal current source is switched-off, capacitor C
R
The start level and the time constant of the rising primary current can be adjusted
externally by changing the values of R
Soft stop is achieved by switching on the internal current source I
charges C
charge current will flow as long as the voltage on pin SNSCURPFC is below the maximum
PFC soft start voltage (typ. 0.5 V). If V
voltage, the soft start current source will start limiting the charge current. To accurately
determine if the capacitor is charged, the voltage is only measured during the off-time of
the PFC power switch. The operation of the PFC is stopped when V
V
The maximum peak current is limited cycle-by-cycle by sensing the voltage across an
external sense resistor (R
voltage is measured via the SNSCURPFC pin and is limited to V
A voltage peak will appear on V
the discharging of the drain capacitance. The leading edge blanking time, t
ensures that the overcurrent sensing block will not react to this transitory peak.
(pin SNSMAINS)
The voltage on the SNSMAINS pin is sensed continuously to prevent the PFC trying to
operate at very low mains input voltages. PFC switching stops as soon as V
drops below V
protection.
V
mains input voltage recovers after a mains-dropout. The PFC (re)starts once V
exceeds the start level V
An overvoltage protection circuit has been built in to prevent boost overvoltages during
load steps and mains transients.
I
τ
Cur PFC
stop(ss)(PFC)
SNSMAINS
ss(PFC)
=
(
R
ss PFC
(
ch(ss)(PFC)
and the peak current increases.
) pk
(
ss(PFC)
is clamped to a minimum value of V
.
)
)
×
=
uvp(SNSMAINS)
C
All information provided in this document is subject to legal disclaimers.
V
---------------------------------------------------------------------------------------------
ss PFC
and the increasing capacitor voltage reduces the peak current. The
charges the capacitor to V
ocr PFC
(
(
Rev. 2 — 9 February 2011
)
start(SNSMAINS)
)
cur(PFC)
–
. Mains undervoltage protection is also called brownout
(
I
R
ch ss
cur PFC
SNSCURPFC
( ) PFC
) connected to the source of the external MOSFET. The
(
(
.
SNSCURPFC
ss(PFC)
)
)
×
Resonant power supply control IC with PFC
R
when the PFC MOSFET is switched on due to
ss(PFC)
SNSCURPFC
ss PFC
and C
(
pu(SNSMAINS)
exceeds the maximum PFC soft start
and a capacitor C
)
cur(PFC)
ss(PFC)
)
= I
.
. At start-up, an internal current
ch(ss)(PFC)
for fast restart as soon as the
ss(PFC)
ocr(PFC)
clamp(ss)PFC
ch(ss)(PFC)
TEA1713T
ss(PFC)
× R
SNSCURPFC
discharges across
© NXP B.V. 2011. All rights reserved.
ss(PFC)
.
.This current
between
leb(PFC)
SNSMAINS
. The
. The
SNSMAINS
>
,
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