TEA1750 NXP Semiconductors, TEA1750 Datasheet - Page 24

• Manufacturer Part Number: TEA1750
• Description: GreenChip III SMPS control IC
• Manufacturer: NXP Semiconductors

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NXP Semiconductors
Table 5.
T
the IC; unless otherwise specified.
[1]
[2]
[3]
[4]
[5]
11. Application information
TEA1750_2
Product data sheet
Symbol
Temperature protection
T
T
amb
pl(IC)
pl(IC)hys
For a typical application with a compensation network on pin PFCCOMP, like the example in
Typically 120 mV above V
Minimum required voltage change time for valley recognition on pin PFCAUX.
Minimum required time between demagnetization recognition and V/ t end.
Guaranteed by design.
= 25 C; V
Characteristics
CC
= 20 V; all voltages are measured with respect to ground (pin 2); currents are positive when flowing into
Parameter
IC protection level
temperature
hysteresis of IC protection
level temperature
A power supply with the TEA1750 consists of a power factor correction circuit followed by
a flyback converter. See
Capacitor C
rectified mains during start-up and via the auxiliary winding of the flyback converter during
operation. Sense resistors R
MOSFETs S1 and S2 into a voltage at pins PFCSENSE and FBSENSE. The values of
R
In the example given, the LATCH pin is connected to a Negative Temperature Coefficient
(NTC) resistor. When the resistance drops below
protection is activated.
A capacitor C
after 10 ms the time-out protection is activated. R
capacitor does not interfere with the normal regulation loop.
R
normal operation due to negative voltage spikes across the sense resistors.
Resistor R
applications with high transformer ringing frequencies (after the secondary stroke), the
PFCAUX pin should be connected via a capacitor and a resistor to the auxiliary winding. A
diode must than be placed from the ground connection to the PFCAUX pin.
SENSE1
S1
stop(fb)
…continued
and R
.
and R
S2
AUX1
VCC
are added to prevent the soft-start capacitors from being charged during
TIMEOUT
SENSE2
is added to protect the IC from damage during lightning events. For
buffers the IC supply voltage, which is powered via the high voltage
Rev. 02 — 15 December 2008
is connected to the FBCTRL pin. For a 120 nF capacitor, typically
define the maximum primary peak current in MOSFETs S1 and S2.
Figure
Conditions
SENSE1
14.
and R
SENSE2
convert the current through the
LOOP
V
--------------------------------
I
prot LATCH
O LATCH
is added so that the time-out
Figure
GreenChip III SMPS control IC
3.
Min
130
-
=
15.6 k
Typ
140
10
TEA1750
© NXP B.V. 2008. All rights reserved.
(typ), the
Max
150
-
24 of 29
Unit
C
C