Digital CMOS design primarily suffers with tradeoff between speed and power dissipation. By contrast analog circuits involve various design aspects where almost every two parameters trade off with each other. The analog design octagon has following parts to consider:

1. Noise: Noise is an error or undesired random disturbance of a useful information signal in a communication channel. The noise is a summation of unwanted or disturbing energy from natural and/or man-made sources.

2. Linearity: it gives the circuit behaviour and the relation between input, output characteristics of the opamp should be linear. If there is non-linear characteristic, then the design is difficult.

3. Gain: the amplifier is used to improve the signal strength of the very weak signal hence gain should be very high.

4. Supply voltage: higher is supply voltage more will be the power dissipation.

5. Voltage swing: it is not fixed in analog circuit.

6. Speed: higher is the speed higher will be the power dissipation.

7. Input/output impedance: it is difficult to match input/output impedenace.

8. Power dissipation:CMOS circuits dissipate power by charging the various load capacitances whenever they are switched. In one complete cycle of CMOS logic, current flows from VDD to the load capacitance to charge it and then flows from the charged load capacitance to ground during discharge. Therefore in one complete charge/discharge cycle, a total of Q=CLVDD is thus transferred from VDD to ground. Multiply by the switching frequency on the load capacitances to get the current used, and multiply by voltage again to get the characteristic switching power dissipated by a CMOS device: P=CV2f.

It is impossible to consider all of the parameters for a design imposing a challenge in designing high performance circuit which would require the best acceptable compromise.