Pro Audio Design Forum

Congratulations.
I was worried with the up tree tangle, I am glad it is over and safe.

Edit. Good move to a safe direction.
Not done, yet.
Tangles can be nasty, double care about unpredictable moves from spring effects.

The Aussie way for trees near a house. They set a rope from a hight main branch going through a shackle at a loop around the base of another tree to a strong vehicle ready for pulling. To get high up to the top of the tree they use a string with a small bag full of lead pieces, they throw up to the ...

YATMA is an approach that takes care nicely of the RdsON mismatch of the switches. The measurement is done directly at the DUT, so the voltage drop, RdsON * Ie, does not come in the measurement. It comes in indirectly though, because the current to the DUT depends a little bit of RdsON. Applied to a...

Merry Xmas. Have à good time.

I'm not planning on using 1.5 mA due to contact resistance but I do want to current limit Ic in the event a device is inserted backwards. I would not worry about inserting backward. Edit: With supply voltage not too high: Base Emitter breakdown voltage is given as 8V typical, 6V minimum. The pinout...

The smoothed average Vbe, which is subject to the Vos of the OP07, is used to set the cutoff voltage. I had previously used the emitter node. To turn the transistors off, I suggest, you switch the bases at a -1.2V node. This gives a Vbe reverse biais, a best way to block a BJT. This way was a must ...

Self-heating is made x10 lower in the Ian Fritz matching gig, where Vce is 1.2V instead of the 12V supply.

The figures I used are from Maxim. https://www.maximintegrated.com/en/products/analog/analog-switches-multiplexers/DG413.html They are general worst case figures, giving a wide upper bound about the measurement accuracy. Your analysis is far more accurate. Actual accuracy is much better than 65μV. T...

Error from DG413 switches.
Delta Ron max 3 Ohm.
So with Ic 1mA, Hfe 100. Error max delta Vb is 30μV.
Ron max 35 Ohm.
So with Delta Hfe 10%. Error max delta Vb is 35 μV.

Overall measurement error from the DG314 is 65μV max @1mA Ic.