M5480

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POWER DISSIPATION OF THE IC

The power dissipation of the IC can be limited us-

ing different configurations.

Figure 7.

In this application R must be chosen taking into ac-

count the worst operating conditions.

R is determined by the maximum number of seg-

ments activated.

The worst case condition for the device is when

roughly half of the maximum number of segments

are activated.

It must be checked that the total power dissipation

does not exceed the absolute maximum ratings of

the device.

In critical cases more resistors can be used in con-

junction with groups of segments.

In this case the current variation in the single resis-

Figure 8.

In this configuration the drop on the serial connect-

ed diodes is quite stable if the diodes are properly

chosen.

The total power dissipation of the IC depends, in a

first approximation, only on the number of seg-

ments activated.

Figure 9.

tal power dissipation of the IC depends only on the

number of segments activated.

R

R

V

C

V

DMAX

–

V

OMIN

–

N

MAX

L

D

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