tea1733t NXP Semiconductors, tea1733t Datasheet - Page 13

• Manufacturer Part Number: tea1733t
• Description: Greenchip Smps Control Ic
• Manufacturer: NXP Semiconductors

NXP Semiconductors
11. Application information
TEA1733T_TEA1733LT_1
Objective data sheet
Fig 10. Typical application
1 M
R3
A power supply with the TEA1733(L) is a flyback converter operating in Continuous
conduction mode. See
Capacitor C5 buffers the IC supply voltage, which is powered via R3 for start-up and via
the auxiliary winding during normal operation. Sense resistor R9 converts the current
through the MOSFET S1 into a voltage at pin 4 (ISENSE). The values of R9 defines the
maximum primary peak current in MOSFETs S1.
In the example given, the PROTECT pin (pin 6) is used for OVP and OTP. The OVP level is
set by Z1 to V
(NTC) resistor R4. The VINSENSE pin (pin 5) is used for mains voltage detection and R1
and R2 set the start voltage to about 80 V (AC). The overpower protection time, defined
by C4, is set to 60 ms.
The restart time, defined by C4 and R8, is set to 0.5 s.
R6 and C6 define the soft start time. R5 is added to prevent the soft start capacitor from
being charged during normal operation due to negative voltage spikes across the current
sense resistor R9.
C3 is added to reduce the noise on the CTRL pin. R7 reduces the peak current to C5.
25 V
C1
68 F
Z1
100 nF
82 k
C2
R2
R4
200 k
R1
10 M
CC
C3
10 nF
= 25.8 V. The OTP level is set by Negative Temperature Coefficient
220 nF
C4
Rev. 01 — 26 October 2009
Figure
R8
2.2 M
5
6
7
8
TEA1733T
10.
4.7 F
4
3
2
1
C5
TEA1733T; TEA1733LT
470
R5
10
R10
220 nF
22 k
0.25
R6
C6
10
R7
R9
S1
GreenChip SMPS control IC
© NXP B.V. 2009. All rights reserved.
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