I saw these lines in a data sheet:
"To reduce unwanted capacitance, TI recommends cutting out the power and ground traces underneath the signal input and output pins. Otherwise, ground and power planes must be unbroken elsewhere on the board. When configuring the amplifier as a TIA, if the required feedback capacitor is under 0.15 pF, consider using two series resistors, each of half the value of a single resistor in the feedback loop to minimize the parasitic capacitance from the resistor."
- I know the ground plane cut-out is to reduce capacitance, but I don't really understand why. Also, why these ties to ground planes must be unbroken elsewhere?
- Why do two resistors have lower capacitance? Is it because capacitance in series has a lower total capacitance?