MP4034 – OFFLINE LED DRIVER

MP4034 Rev. 1.02

www.MonolithicPower.com

12

12/4/2013

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will restart.

1

2

N-1

N

Figure 8: LED String

and the total number of LEDs on the string is N.

So the output voltage can be calculated as

output voltage when OVP occurs. So the

voltage reflected on the FB pin should be:

P_ AU

DOWN

FB

F

D

FBOVP1

SDOWN

UP

N

R

V

(N V

V ) 0.85V

NR

R

=×

×

×

+

=

+

Open-Circuit Protection (OCkP)

The

MP4034

has

open-circuit

protection

not be monitored—which means the feedback

loop is open—the MP4034 immediately shuts

off the driving signals and enters hiccup mode.

The MP4034 resumes normal operation when

the fault has been removed.

Thermal Shutdown (TSD)

When the temperature of the IC exceeds 150°C,

the over-temperature protection is enacted and

the IC enters auto-recovery mode. When the

temperature falls below 120°C, the IC resumes

working.