SSL4101T

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Product data sheet

Rev. 1 — 21 April 2011

17 of 29

NXP Semiconductors

SSL4101T

GreenChip III+ SMPS control IC

7.3.9 Overcurrent protection (FBSENSE pin)

The primary peak current in the transformer is measured accurately cycle-by-cycle using

an internal level (see also Section 7.3.3). The OCP detection is suppressed during the

7.3.10 Overpower protection

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 Figure 14.

7.3.11 Driver (FBDRIVER pin)

The driver circuit to the gate of the external power MOSFET has a current sourcing

capability of typically

−500 mA and a current sink capability of typically 1.2 A. This permits

fast turn-on and turn-off of the power MOSFET for efficient operation.

Fig 13. OCP leading edge blanking

OCP level

t

014aaa022

Fig 14. Overpower protection curve

−400

−360

0

−100

−300

−200

014aaa096

0.4

0.5

0.6

(V)

0.3

0.52

0.37