點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路9號7樓之1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
DM634
Tel：886-3-5645656
Fax：886-3-5645626
Output to Output Delay
DM634 has build-in output to output delay with a special arrangement. This arrangement help
chip avoid noise cause by large current during channels switching. The arrangement details are
shown as following table.
Channel 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Delay units 0 4 1 5 2 6 3 7 3 7 2 4 1 5 0 4
Power Dissipation
The power dissipation of a semiconductor chip is limited to its package and ambient
temperature, in which the device requires the maximum output current calculated for given
operating conditions. The maximum allowable power consumption can be calculated by the
following equation:
Tj(junction temperature)(max)(°C)– Ta(ambient temperature)(°C)
Pd(max)(Watt) =
Rth(junction-to-air thermal resistance)(°C/Watt)
The relationship between power dissipation and operating temperature can be referred to the
figure below:
5
4.5
4
TSSOP24E
Tj(max)=150°C
Rth(TSSOP24E)=29°C/Watt
Rth(SOP24)=50°C/Watt
Rth(SSOP24)=69°C/Watt
3.5
3
SOP24
2.5
2
SSOP24
1.5
1
0.5
0
0
20
40
60
80
100
120
140
160
Ambient Temperature Ta ( ℃ )
The power consumption of IC can be determined by the following equation and should be less
than the maximum allowable power dissipation:
16-channel 16-bit PWM Constant Current LED Driver
Version : A.003
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