Electronics - Analog Circuits

A: Option A tracks the physics: doubling C_load shifts the pole at the output, chewing up phase margin. A small isolating resistor decouples the capacitive load and moves the zero where it helps. B sounds tempting if you're thinking noise budgets, but Johnson noise doesn't create sustained oscillation. C mixes up static gain error with dynamic stability; cranking gain often makes phase margin worse. D feels practical in the lab, but sampling rate doesn't change the analog loop that's already unstable between conversions.

A: A matches both symptoms: stable at low signal, unstable when the diode capacitance is effectively higher under illumination and the loop gain is pushed. B would drift, not snap and recover. C explains gain error but not rail-to-rail bursts tied to dynamics. D can cause weird behavior, but you'd see it across operating points, not only when photocurrent ramps.

A: A is the uncomfortable answer: vendors do change pin functions across suffixes, and tying what is now NC or test silicon can inject noise. B is a common shortcut that fails during corner cases. C ignores that the netlist comes from the symbol. D assumes backward compatibility that the datasheet doesn't promise.

A: A respects reality: output swing is load- and temperature-dependent, and those checks come before tuning. B feels practical but bakes in an arbitrary margin. C is how saturation bugs escape FAT and show up later. D hides the problem by constraining the process instead of validating the hardware capability.