DM115B

點晶科技股份有限公司

SILICON TOUCH TECHNOLOGY INC.

8-BIT CONSTANT CURRENT LED DRIVERS with 3.3V~5V supply voltage

Version:A.001

Page 11

Note

As the power dissipation of a semiconductor chip is limited its package and ambient temperature,

this device requires a maximum output current be calculated for a given operating condition. The

maximum allowable power consumption (Pd (max)) of this device is calculated as follows:

)

/

(

Rth

)

)(

)

emperature

(ambient t

Ta

-

(max)

e)

temperatur

(junction

(Tj

)

(max)(

Watt

C

C

Watt

Pd

°

°

=

Based on the Pd (max), the maximum allowable current can be calculated as follows:

Imax - Ta ( DM115 )

0

10

20

30

40

50

60

70

0

20

40

60

80

100

120

140

160

Ta

Pd - Ta

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

0

20

40

60

80

100

120

140

160

Ta

DIP

SOP

SSOP

DIP

SOP

SSOP