8.2.1.2.1 Configuration Example

In a 3.3-V system, 3.2 V ≤ V_ref ≤ 3.4 V. Use Equation 3 to calculate the allowable range for R1.

Equation 3.

For this design example, use Equation 4 to calculate the allowable range of R1.

Equation 4.

Therefore:

After finding the allowable range of R1 (Equation 5), select a value between 500 Ω and 32 kΩ for R1.

Assuming a system bandwidth of 10 kHz, use Equation 6 to calculate the value of C2.

Equation 6.

For this design example, use Equation 7 to calculate the value of C2.

Equation 7.

An R1 value of 10 kΩ and a C2 value less than 820 pF satisfy the requirement for a 10-kHz system bandwidth.

For R1 = 10 kΩ and C2 = 680 pF, the corner frequency for the low-pass filter is 23.4 kHz.