TEA1750T/N1,518 NXP Semiconductors, TEA1750T/N1,518 Datasheet - Page 17

IC PFC CONTROLLER DCM16SOIC

TEA1750T/N1,518

Manufacturer Part Number
TEA1750T/N1,518
Description
IC PFC CONTROLLER DCM16SOIC
Manufacturer
NXP Semiconductors
Series
GreenChip™ IIIr
Datasheet

Specifications of TEA1750T/N1,518

Mode
Discontinuous Conduction (DCM)
Frequency - Switching
125kHz
Current - Startup
60µA
Voltage - Supply
14 V ~ 22 V
Operating Temperature
-40°C ~ 150°C
Mounting Type
Surface Mount
Package / Case
16-SOIC (3.9mm Width)
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
935282967518
TEA1750T-T
TEA1750T-T
NXP Semiconductors
TEA1750_2
Product data sheet
7.3.7 Maximum on-time
7.3.8 Overvoltage protection (FBAUX pin)
The flyback controller limits the ‘on-time’ of the external MOSFET to 25 s (typ). When the
‘on-time’ is longer than 25 s, the IC stops switching and enters the safe restart mode.
An output overvoltage protection is implemented in the GreenChip III series. This works
for the TEA1750 by sensing the auxiliary voltage via the current flowing into pin FBAUX
during the secondary stroke. The auxiliary winding voltage is a well-defined replica of the
output voltage. Voltage spikes are averaged by an internal filter.
If the output voltage exceeds the OVP trip level, an internal counter starts counting
subsequent OVP events. The counter has been added to prevent incorrect OVP detection
which might occur during ElectroStatic Discharge (ESD) or lightning events. If the output
voltage exceeds the OVP trip level a few times and not again in a subsequent cycle, the
internal counter counts down at twice the speed it uses when counting up. However, when
typically 8 cycles of 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.
V
Fig 12. Soft start-up of flyback
o ovp
=
s
is the number of secondary turns and N
----------- - I
N
N s
aux
FBAUX
ovp FBAUX
ovp(FBAUX)
can be adjusted to the turns ratio of the transformer, thus making an
Rev. 02 — 15 December 2008
ovp(FBAUX)
R SENSE2
S2
R SS2
C SS2
FBAUX
at which the OVP function trips, can be set by the
R
is internally trimmed.
FBAUX
:
10
FBSENSE
I start(soft)fb
+
V
clamp FBAUX
60 A
+
0.5 V
aux
SOFT START
CONTROL
is the number of auxiliary turns of the
OCP
GreenChip III SMPS control IC
014aaa020
TEA1750
© NXP B.V. 2008. All rights reserved.
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