Comments for a random electronoblog - Allan Wang

Comment on Current starved ring oscillator VCO for PDN characterization by Samir

Samir — Tue, 13 Mar 2012 13:02:40 +0000

I want to design such type of current-starved VCO but its differential variant. Would you please let me know any design guideline.

Comment on TLC5947 32x RGB LED board by Allan Wang

Allan Wang — Wed, 08 Feb 2012 22:08:19 +0000

Lars, I think I saw a post on the TI E2E forum about putting transistors at the output of the TLC5947. I believe it can be done since all the TLC5947 does is sink current or open circuit. However relying on an external discrete transistor to do current limiting based on its beta is a very bad idea due to large beta variance in manufacturing and also over temperature and operating conditions.

Comment on TLC5947 32x RGB LED board by Lars

Lars — Wed, 08 Feb 2012 13:15:56 +0000

I was wondering if you can help me with something. Do you think the TLC5947 can pwm AND still current limit high power leds if I put a transistor between the outputs and the led? So that a transistor with a amplification factor of 100 would give an 100*30=3000mAh current limit?

thanks in advance.

Comment on Yet another PCB business card (with touchpad!), part 1 by Gerar

Gerar — Fri, 28 Oct 2011 17:50:49 +0000

Which pic do you use? Nice project i’m trying to do something like that.

Comment on RGB Stick by Michael Hofmann

Michael Hofmann — Mon, 17 Oct 2011 15:14:03 +0000

Hello,
I am interested in two of these LED sticks.
You wrote that you require for the PCB $ 5.

I would like to buy two.
What is the shipping cost to Germany?

I have send you an E-Mail.

Greetings: Michael

Comment on CMOS Op-Amp Design by kiran

kiran — Fri, 07 Oct 2011 23:33:45 +0000

Is that cadence design??

Comment on Digilent Atlys FPGA board by Ryan

Ryan — Fri, 16 Sep 2011 02:01:12 +0000

Haha I just noticed Kevin Vermeer’s name. I read that kids responses on Buzz every once in a while. I wouldn’t recommend paying any attention to him…

Comment on Digilent Atlys FPGA board by Ryan

Ryan — Fri, 16 Sep 2011 01:57:07 +0000

Samtec part: VHDCP-68-01-M-EM

I ordered samples and had them on my doorstep 2 days later, free of charge. Don’t you guys know about samples? Yes it’s edgemount and you will have to deal with via’s under certain conditions but it’s a connector… If a via is going to make a big difference, well a connector is going to make a bigger difference. A program like Altium will still allow you to balance a set of 10 traces while only having via’s on a few.

Comment on TLC5947 32x RGB LED board by Hank

Hank — Tue, 30 Aug 2011 03:17:27 +0000

Too many cmoplmintes too little space, thanks!

Comment on RGB Stick by Fanis

Fanis — Fri, 26 Aug 2011 21:46:26 +0000

Sorry, I put 2 links that the post did not get :

The first is for

en . wikipedia . org / wiki / Color_depth

and the second is for

en . wikipedia . org / wiki / List_of_colors