UM10406

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User manual

Rev. 01 — 3 August 2010

8 of 21

NXP Semiconductors

UM10406

SSL1523 5 W LED driver

The constant power output occurs at output voltages above 23 V combined with an output

power exceeding 5 W, see also Section 9, Figure 9. In this area, constant output power

becomes the dominant control mechanism. At very low output voltages, the feedback loop

will become non-functional, resulting again in constant output power mode. An output

short-circuit will cause an output current of about 1 A, resulting in increased stress on the

transformer TX1, shunt resistor R10, the output diode D10, and the snubber diode D3.