Recent Posts

1

Computers / Re: Format a 256GB pendrive with FAT32 using a windows 10 pc

« Last post by IanB on Today at 06:43:23 am »

Not sure if it's a GUI on top of command line tools or a GUI and command line tools on top of C/C++ libraries and APIs.

More or less the second one. Both GUI and command line tools call APIs to do their work.

2

Test Equipment / Re: Siglent SDS3000X HD and upgraded SDS1000X HD

« Last post by core on Today at 06:41:10 am »

I'm waiting for a teardown showing which FPGA and ADC are used in the SDS800X HD. The ADC converter seems to have the smaller capsule vs the SDS1000X HS, but the FPGA might be the same.

Indeed, it's a shame to waste resources, in the sense of not making full use of the ADC converter. 2 x 2GS/s would have made more sense.

If there were limits in the FPGA for example, it would have been logical and cheaper to use an ADC with 4 x 1GS/s channels in the same capsule.

However, we can still enjoy these devices considering the price/performance ratio.

3

Computers / Re: Format a 256GB pendrive with FAT32 using a windows 10 pc

« Last post by selcuk on Today at 06:38:31 am »

If you have a similar issue while formatting an SD card and found this topic, there is an official tool from SD card association:

https://www.sdcard.org/downloads/formatter/

4

Projects, Designs, and Technical Stuff / Re: (Yet Another) DIY Multislope ADC

« Last post by iMo on Today at 06:34:41 am »

..The project files are available, so it should be possible to get your own set of boards for experimentation, or replicate the core circuit (it's quite simple) on a breadboard..

Yep, the analog part of the design is an another story which we have not elaborated yet
My basic motivation has been to have a look at the 2040/PIO and its applicability. Of course it could be done by a stm32xxx (here we lack the PIO) or an fpga+MCU (here the complexity is higher) as well.
Hopefully rPi company will come with the rp2041 soon - with the fixed ADC, and with 4xPIO with 256 instructions each

5

Microcontrollers / Looking for information on TEST pin and ways to DUMP mask ROM of PIC1650 PIC16xx

« Last post by reverse on Today at 06:31:41 am »

Hi. Looking for information on TEST pin and ways to read out the mask firmware ROM on GI's (General Instruments) PIC1650  (PIC16xx) family of microcontrollers.

6

Projects, Designs, and Technical Stuff / Re: Opamps - Die pictures

« Last post by Noopy on Today at 06:29:16 am »

Nice! Thank you very much! 
Would it be ok for you if I put your schematic on my website?

7

Computers / Re: Format a 256GB pendrive with FAT32 using a windows 10 pc

« Last post by magic on Today at 06:27:10 am »

Not sure if it's a GUI on top of command line tools or a GUI and command line tools on top of C/C++ libraries and APIs.

"GUI on top of command line tools" is how Linux Desktop stuff works, when it does

8

Test Equipment / Re: Standardised Way To Test Oscilloscope Screen Update Rate

« Last post by EEVblog on Today at 06:26:10 am »

I am thinking about the purpose of the refresh rate.
Perhaps the screen refresh rate is less important than the ability to display the waveform appropriately – so a waveform with a 'glitch' repeated at different rates could be used to test for this.

Yes, in theory the display refresh/update rate shouldn't matter if the scope is designed to or set up to capture the thing you are interested in. Persistance is one obvious way to do that for example.
But often you are just causally using you Mk1 eyeball probing around, in whcih case you don't want your fast waveform capture rate hindered by a slow display update rate.

9

General Technical Chat / Re: Relay trigger when voltage above 13v

« Last post by dietert1 on Today at 06:24:10 am »

Here is TI's app note on using the TL431 as a comparator:

Using the TL431 for Undervoltage and Overvoltage Detection
https://www.ti.com/lit/an/slva987a/slva987a.pdf
..

I would replace the bipolar transistor of Figure 6 in that app note by a p-channel mosfet in order get rid of the relay. The voltage sense divider causes a small current drain even below threshold.

Regards, Dieter

10

Projects, Designs, and Technical Stuff / Re: Opamps - Die pictures

« Last post by magic on Today at 06:22:15 am »

The circuit is not very complex and the complete schematic would be near but I somehow don´t like MOSFETs... 

Well, CMOS is annoying, but 30 year old CMOS is doable.

Turns out the signal path circuitry is quite simple, a few differential pairs and current mirrors are all there is to it. Looks like a TLC274 chopped into pieces and reassembled semi-randomly. The trick is auto-zero witchcraft and high DC gain achieved by a sequence of four stages with unusual compensation by two Miller caps and two input pairs. BTW, similar compensation is shown in datasheets of modern three stage CMOS opamps from TI like OPA172 or OPA1656; they call it "active feedforward" and I have also seen it called a "multipath" elsewhere.

The critical pairs gm1 and gm6 use striped common centroid layout ABBAABBA and their mirrors are ABBA. The offset compensation pairs gm3 and gm4 are oriented perpendicularly to output stage heat gradient but don't bother with common centroid. The other small stage gm2 is single-ended and the output stage is a simple rail to rail contraption: M56 sinks load current directly, M51 steals current away from current mirrors driving M55. This arrangement ensures that M56 never turns off, so compensation keeps working when the output sources current.

M58 is a dummy transistor in parallel with C1 which appears to compensate for capacitance added to C2 by M56. It isn't exactly identical to M56, but they must have made it work somehow.