gnurf, thank you.
This forum is lovely coz a lot of ppl like u and yungman are here. :)
Yes , actually I planned to place the GND (2nd) layer closer to 1st layer. Those critical signals will be placed on 1st layer.
The component placement annoyed me much since there are so many of them. I...
Thanks, yungman. Your reply are always so prompt and detailed.
Sorry for the missing information. It's a low frequency case rather than a RF one. I put decoupling capacitances right next to each supply pin of OP AMPs.
These OP-Amps uses dual supplies (+15 and -15 Volts with common analog...
I have 16 channels of the same circuit shown below.
I have positive and negative power supplies ( 15V,-15V, 1A, TI LDOs).
Can anybody tell me how to deal with power layout for the OP-AMPs if I use 4-layer (Signal-PWR_GND-Signal) PCB board?
Please show me your picture if you have.
Thank you!
Geez, unfortuantely I have to dump everything to myself.:devil:
I tried to use two wilson current mirrors as source and sink, but I couldn't figure out how to swtich them fast enough. Although I like the idea that possibly gets higher freqency current, I have to give it up.
I will follow the...
Hi,yungman.
I have to use current source because I need a 'constant' current (periodically) to interact with the DUT to study its aging mechanism. You know, in many cases a 'constant' test condition must be built for characterization.
I measure the resistance of the DUT through a RMS-DC...
Hi,yungman. Thanks for the detailed explanation of the working principles of Q3 and Q4. Very clear.
Sorry for the missing information on the application of the current source. My experiments need 24 channel current sources at the same time to drive 24 special resistors whose resistance will...
Thanks for replies and the technical note provided by NascentOxygen.
The MOSFET idea is good. Some current-source circuits do use switches to get AC current with frequency up to KHz easily. But I am not sure if the ciucuit works well up to Mega Hertz because I cannot understand the working...
Hi, Yungman. Thank you very much for your detailed reply.:approve:
The circuit you share should work but it seems too difficult for me. Because I am a newbie to electrical engineering, I need a simple solution where as less components as possilbe are used.
I wonder if I can build the current...
Hi,
I want to build a current source capable of generating pulsed-DC current (unipolar square wave) and pulsed-AC current(bipolar square wave) .
The current frequency is from 100 Hz to 1 MHz.
The current amplitude is from 0.2 to 0.5 mA. (1 uA resolution preferred)
Adjustable duty...