TEA1751LT/N1 NXP Semiconductors, TEA1751LT/N1 Datasheet - Page 18

• Manufacturer Part Number: TEA1751LT/N1
• Description: AC-DC, PFC, FLYBACK, CNTRL, 16SOIC
• Manufacturer: NXP Semiconductors

Specifications of TEA1751LT/N1

• Input Voltage: 276V
• Output Current: 1.2A
• Output Voltage: 11V
• No. Of Outputs: 2
• Power Dissipation Pd: 600mW
• Voltage Regulator Case Style: SOIC
• No. Of Pins: 16
• Operating Temperature Range: -40°C To
• Supply Voltage Range: 21V To 23V
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

NXP Semiconductors
TEA1751T_LT_2
Product data sheet
7.3.10 Overpower protection
7.3.9 Overcurrent protection (FBSENSE pin)
subsequent OVP events are detected, the IC assumes a true OVP and the OVP circuit
switches the power MOSFET off. As the protection is latched, the converter only restarts
after the internal latch is reset. In a typical application the mains should be interrupted to
reset the internal latch.
The output voltage V
demagnetization resistor, R
where N
transformer. Current I
The value of R
accurate OVP detection possible.
The primary peak current in the transformer is measured accurately cycle-by-cycle using
the external sense resistor R
an internal level (see also
leading edge blanking period, t
During the primary stroke of the flyback converter the input voltage of the flyback
converter is measured by sensing the current that is drawn from the pin FBAUX.
The current information is used to adjust the peak drain current of the flyback converter,
which is measured via pin FBSENSE. The internal compensation is such that an almost
input voltage independent maximum output power can be realized.
The OPP curve is given in
V
Fig 15. OCP leading edge blanking
o OVP
(
)
s
=
is the number of secondary turns and N
----------- I
N
N s
aux
FBAUX
(
ovp FBaux
o(OVP)
(
can be adjusted to the turns ratio of the transformer, thus making an
Rev. 02 — 23 December 2009
ovp(FBAUX)
Section
Figure
at which the OVP function trips, can be set by the
)
FBAUX
OCP LEVEL
×
sense2
V
LEB (t
FBSENSE
R
leb
is internally trimmed.
FBaux
, to prevent false triggering caused by switch-on spikes.
:
16.
leb
. The OCP circuit limits the voltage on pin FBSENSE to
7.3.3). The OCP detection is suppressed during the
)
+
V
clamp FBAUX
TEA1751T; TEA1751LT
(
aux
is the number of auxiliary turns of the
)
)
014aaa022
GreenChip III SMPS control IC
t
© NXP B.V. 2009. All rights reserved.
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