|
|
Teilenummer | DD311 |
|
Beschreibung | HIGH CONSTANT CURRENT LED DRIVER | |
Hersteller | SiTi | |
Logo | ||
Gesamt 20 Seiten DD311
Version : A.002
Issue Date : 2008/12/09
File Name : SP-DD311-A.002.doc
Total Pages: 19
HIGH CONSTANT CURRENT LED DRIVER
新竹市科學園區展業一路 9 號 7 樓之 1
SILICON TOUCH TECHNOLOGY INC.
9-7F-1, Prosperity Road I, Science Based Industrial Park,
Hsin-Chu, Taiwan 300, R.O.C.
Tel:886-3-5645656 Fax:886-3-5645626
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.
Tel:886-3-5645656 Fax:886-3-5645626
Optional
R
C
IREF
REXT
EN
OUT
VSS
GND
DD311
VL
RL
CLED
Optional
CL
Switching Characteristics Test Circuit
Transient Characteristics
In order to reduce the overshoot or undershoot(Vout) during switching large current, it is
recommended adding a large enough capacitor between VLED and GND to keep LED supply
voltage(VLED) stable. The longer rise time and fall time of the EN dimming signal, adjustable by
RC filter, produce the smooth transient response of output current. The two output waveforms
illustrating the EN dimming signal with and without RC filter are given below:
without RC filter
HIGH CONSTANT CURRENT LED DRIVER
with RC filter
Version:A.002
Page 5
6 Page 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.
Tel:886-3-5645656 Fax:886-3-5645626
Power Dissipation
DD311
Notice that 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 refer to the figure
below:
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0
Tj(max)=125 °C
Rth=23.38 °C/Watt
20 40 60 80 100 120 140
Ambient Temperature Ta(°C)
Based on the Pd(max), the maximum allowable voltage of output terminal can be calculated as
follows:
Pd(max)(Watt)– VREXT(Volt) × IREF(A)
Vout(max)(Volt) =
Iout(A) × Dimming Duty
HIGH CONSTANT CURRENT LED DRIVER
Version:A.002
Page 11
12 Page | ||
Seiten | Gesamt 20 Seiten | |
PDF Download | [ DD311 Schematic.PDF ] |
Teilenummer | Beschreibung | Hersteller |
DD311 | HIGH CONSTANT CURRENT LED DRIVER | SiTi |
DD312 | High Constant Current LED Drivers | SiTi |
DD313 | 3-Channel High Constant Current LED Driver | SiTi |
DD313-4 | 40V Adjustable Current Sink Linear LED Driver | SiTi |
Teilenummer | Beschreibung | Hersteller |
CD40175BC | Hex D-Type Flip-Flop / Quad D-Type Flip-Flop. |
Fairchild Semiconductor |
KTD1146 | EPITAXIAL PLANAR NPN TRANSISTOR. |
KEC |
www.Datenblatt-PDF.com | 2020 | Kontakt | Suche |