ZHCSCB3D March 2014 – March 2018 PCM1860 , PCM1861 , PCM1862 , PCM1863 , PCM1864 , PCM1865
PRODUCTION DATA.
Most systems can simply use an input filter similar to the one shown in Figure 60. However, for systems with significant out-of-band noise, a simple filter such as that shown in Figure 61 can be used for pre-ADC, antialiasing filtering. The recommended resistor value for the antialiasing filter is 100 Ω. Place film-type capacitors of 0.01 µF as close as possible to the VINLx and VINRx pins, and terminate to GND as close as possible to the AGND pin in order to maximize the dynamic performance of the ADC.
Adding this filter resistor also adds some input current limiting into the device, if the ESD diodes begin to clamp the signal when the maximum input voltage is exceeded. Keep the current through the input ESD diodes as low as possible, with ~5 mA treated as a absolute maximum. Any higher and the ESD diodes may fail because of the thermal constraints.