TL082-Q1: How the balance resistance is calculated

Hello Hazel,

For an op amp with significant input bias current, R3 = R1 || R2 = (R1 * R2) / (R1 + R2)

TL082 does not have significant input bias current so R3 could be zero. However make R3 between 1k and 10k to protect input pin from system faults or poor layouts.

Hi Hazel,

take care, your feedback resistors are such high ohmic that you will run into stability issues. Your phase margin is smaller than 4°:

Better add a phase lead capacitance of 4.7p...10p, as shown below:

hazel_tl082.TSC

C1 restores the phase margin to 74° and ensures stability

Kai