AN10881
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© NXP B.V. 2011. All rights reserved.
Application note
Rev. 2 — 26 September 2011
57 of 102
NXP Semiconductors
AN10881
TEA1713 resonant power supply control IC with PFC
The (dis)charge current can have a high value
160
A or a low value
40
A. The
two-speed soft-start sweep of the TEA1713 allows a combination of a short start-up time
of the resonant converter and stable regulation loops such as overcurrent regulation.
In some cases there can be a situation where overcurrent regulation is activated during
the soft-start sequence. This results in a feedback controlled or corrected soft-start.
The fast (dis)charge speed is used for the upper frequency range where VSSHBC/EN is
below 5.6 V. In the upper frequency range the current and power in the converter do not
react strongly to frequency variations.
The slow (dis)charge speed is used for the lower frequency range where VSSHBC/EN is
above 5.6 V. In the lower frequency range the current in the converter reacts strongly to
frequency variations.
Burst mode
The soft-start capacitor is not charged or discharged during the non-operation time in
Burst mode operation. The soft-start voltage does not change during this time.
Fig 34. OverCurrent Regulation (OCR) during start-up
500 mV
−
500 mV
V
SNSCURHBC
160
μ
A
40
μ
A
−
40
μ
A
−
160
μ
A
I
SSHBC/EN
V
SSHBC/EN
8 V
5.6 V
3.2 V
V
Output
V
regulate
0
0
0
t
t
t
t
Fast soft-start sweep (charge and discharge)
Slow soft-start sweep (charge and discharge)
001aal044
