Yes. I would.On the circuit I sent, if you short circuit the capacitor, the output changes polarity, and messes up.
Given that you are cautioning what may happen in a practical build, should I use preemptive caution, and include 0603, or 0805 pads, with 0Ω links, just in case on power-up, one needs to introduce a capacitor or two?
BTW, LTC6268-10's are back ordered or out of stock at Digikey and Mouser. Strangely, Digikey says they have 2K in stock, but won't sell me 2. I tried ordering 2 and was told an anticipated 11 March delivery. LTC6268's are not available at Digikey, they have 0.
LTC6269's are available only in the DFN-10 package right now, which are tough to solder. I guess I could try with my hot air gun.
Curiously, I can buy LTC6269-10's and they can be bought in MSOP8. Crazy world. I could go all LTC6269-10's and spread out the gain, or just not use one of the stages.
Found something that seems to work, but I am skeptical at this point. LTC6269-10, followed by two LTC6269 devices. DC coupled for the first two stages. Still playing with the last stage. Trying to get rid of 1.35mV offset. To eliminate it I need to introduce -6.81uV to the positive terminal of the last stage. Seems like that node would be touchy and wander with temperature.
0.1pA generates 233uV pulse (2.5V/2^16 = 38.15uV) or 6.1 counts. 1000pA generates 2.332V or 61131.98 counts. 4 decades. This circuit is very sensitive to any offsets, and capacitance. Be fun to try, but it may oscillate like mad. I'm a bit uncertain how to physically arrange the diode and it's bias circuit. Can you guide me on this? Is it just replacing the current sources, resistor and C1 with the following?
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