Figure 3-4 AMC-AMP-200A-EVM Filter Diagram

The AMC-AMP-200A-EVM performance can be adjusted among four circuit filters. With each filter, there is a tradeoff between noise and propagation delay. The weaker the filter, the shorter the propagation delay.

• Input Filter:
  $. {\mathrm{F}}_{\mathrm{C}}=\frac{1}{2\mathrm{\pi RC}}=\frac{1}{2\mathrm{\pi }\times 32\mathrm{\Omega }\times 10\mathrm{nF}}=497\mathrm{kHz}$
  • Selecting a shunt resistor with high inductance when measuring a high frequency signal can cause overshoot in AC measurements. Compensate for overshoot caused by parasitic inductance with proper design of the differential RC filter. Best input filter design is dependent on inductance of resistor and PCB design. An example simulation is shown below for TINA-TI.
    Figure 3-5 Input Filter TINA-TI
• Output filter (unpopulated):
  $. {\mathrm{F}}_{\mathrm{C}}=\frac{1}{2\mathrm{\pi RC}}$
  • Size for additional filtering as desired.
• Differential to single-ended filter:
  $. {\mathrm{F}}_{\mathrm{C}}=\frac{1}{2\mathrm{\pi RC}}=\frac{1}{2\mathrm{\pi }\times 7.87\mathrm{k\Omega }\times 51\mathrm{pF}}=397\mathrm{kHz}$
  • Sized to allow 340kHz AMC3302 output bandwidth. Modify as needed for bandwidth limitations.
• Single-ended output filter:
  $. {\mathrm{F}}_{\mathrm{C}}=\frac{1}{2\mathrm{\pi RC}}=\frac{1}{2\mathrm{\pi }\times 16\mathrm{\Omega }\times 100\mathrm{pF}}=99.5\mathrm{MHz}$
  • Modify as needed for single-ended output signal.