PDF《DD231》

DD231 Version : A.

003 Issue Date : 2009/8/19 File Name : SP-DD231-A.003.doc Total Pages :

7 3-CHANNEL CONSTANT CURRENT LED DRIVERS 新竹市科学园区展业一?

9 号7?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 DD231 点晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. 3-CHANNEL CONSTANT CURRENT LED DRIVERS Version: A.003 Page

1 未经授权而迳予重制、复制、使用或公开本文件,?为人得被追究侵权之相关民刑事责任 Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement. DD231 3-CHANNEL CONSTANT CURRENT LED DRIVERS DESCRIPTION The DD231 is a 3-channel constant current LED driver. It's designed to operate as a constant-current sink to drive the LEDs with an external resistance in low power environment. Because the DD231 directly determines output current by each channel in low Bit-to-Bit skew, it is ideal for driving LED whose light intensity is proportional to the current passing through them, not the voltage across their terminals. This configuration eliminates the need of external capacitors and inductances. With an input voltage range of 3V to 5V, so the device can work in general battery system. The value of constant current can be varied using an external resistor (Iout =

5 ~30mA). GENERAL FEATURES ?Constant Current Output, 5~30mA. ?Supply Voltage VDD is 3V to 5V. ?Bit-to-Bit : ± 3.0% (Max) @ IOUT =

5 ~ 30mA. ?Only Need One External Resistor, No Other External Parts. ?Small 6-Pin SOT26 Package. APPLICATIONS ?White LED Display Backlighting ?Cellular Telephones ?Handheld Computers ?Digital Cameras ?Portable MP3 Players ?Pagers ?Personal Digital Assistant ?E-Books and Sub Notebooks DD231 点晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. 3-CHANNEL CONSTANT CURRENT LED DRIVERS Version: A.003 Page

2 未经授权而迳予重制、复制、使用或公开本文件,?为人得被追究侵权之相关民刑事责任 Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement. Pin Description PIN NAME DESCRIPTION VDD Power supply terminal Rext Input terminal of an external resistor GND Ground terminal Out0 to Out2 Output terminal Maximum Ratings (Ta = 25°C, Tj(max) = 140°C) CHARACTERISTIC SYMBOL RATING UNIT Supply Voltage VDD

7 V Output Current IOUT

30 mA Output Voltage VOUT ~17 V GND Terminal Current IGND

90 mA Power Dissipation PD 0.35 W Operating Temperature Top -40 ~

85 °C Storage Temperature Tstg -55 ~

150 °C Recommended Operating Condition CHARACTERISTIC SYMBOL CONDITION MIN. TYP. MAX. UNIT Supply Voltage VDD ? 2.7 3.3

6 V Output Voltage VOUT ? 0.2 0.6 5.0 V Output Current IO Outn

5 ?

30 mA Operating temperature TOPR ? -40 ?

85 °C Out0 Out1 Out2 Rext GND VDD DD231 点晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. 3-CHANNEL CONSTANT CURRENT LED DRIVERS Version: A.003 Page

3 未经授权而迳予重制、复制、使用或公开本文件,?为人得被追究侵权之相关民刑事责任 Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement. Electrical Characteristics (Typ:VDD = 3.3 V, Ta = 25°C unless otherwise noted) CHARACTERISTIC SYMBOL CONDITION MIN. TYP. MAX. UNIT IOL1 VOUT =

1 V REXT = 12kΩ ? ±1.5 ±3 % Output Current (Bit-Bit) IOL2 VOUT = 0.5 REXT = 60kΩ ? ±1.5 ±3 % Output Current (Chip-Chip) IOL3 VOUT = 1.0V, REXT = 12kΩ 26.3 29.2 32.1 mA Detailed Description 1) Constant Current Output Value Setting The output current is determined by the resistance connected between REXT pin and GND. The approximate relation between the resistance value and the base current value is shown in Fig1, the approximate equation presented in (Eq.1). Iout-Rext 0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00