数据搜索系统,热门电子元器件搜索 |
|
W-6237TD-G3 数据表(PDF) 10 Page - Copal Electronics |
|
W-6237TD-G3 数据表(HTML) 10 Page - Copal Electronics |
10 / 13 page W-6237 10 Dimming Control There are several methods available to control the LED brightness. PWM Signal on the SHDN Pin LED brightness dimming can be done by applying a PWM signal to the SHDN input. The LED current is repetitively turned on and off, so that the average current is proportional to the duty cycle. A 100% duty cycle, with SHDN always high, corresponds to the LEDs at nominal current. Figure 25 shows a 1 kHz signal with a 50% duty cycle applied to the SHDN pin. The recommended PWM frequency range is from 100 Hz to 2 kHz. Figure 25. Switching Waveform with 1 kHz PWM on SHDN Filtered PWM Signal A filtered PWM signal used as a variable DC voltage can control the LED current. Figure 26 shows the PWM control circuitry connected to the W-6237 FB pin. The PWM signal has a voltage swing of 0 V to 2.5 V. The LED current can be dimmed within a range from 0 mA to 20 mA. The PWM signal frequency can vary from very low frequency up to 100 kHz. Figure 26. Circuit for Filtered PWM Signal 1k 3.1 k 0V 2.5 V 0.22 F C1 i VIN W-6237 FB SW GND VIN PWN Signal LED Current RB 3.73 k SHDN R1 15 R2 RA VFB = 300 mV A PWM signal at 0 V DC, or a 0% duty cycle, results in a max LED current of about 22 mA. A PWM signal with a 93% duty cycle or more, results in an LED current of 0 mA. Figure 27. Filtered PWM Dimming (0 V to 2.5 V) 25 20 15 10 5 0 0 10 20 30 40 50 60 70 80 90 100 PWM DUTY CYCLE (%) |
类似零件编号 - W-6237TD-G3 |
|
类似说明 - W-6237TD-G3 |
|
|
链接网址 |
隐私政策 |
ALLDATASHEETCN.COM |
ALLDATASHEET是否为您带来帮助? [ DONATE ] |
关于 Alldatasheet | 广告服务 | 联系我们 | 隐私政策 | 链接交换 | 制造商名单 All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |