SBAU213A September 2013 – July 2020 ADS8860
The circuit shown in Figure 2-2 shows the voltage reference input drive for the SAR ADC. For many SAR ADCs, such as the ADS8860, the reference input is a switched capacitor input. This type of input requires a wide-bandwidth, low-impedance signal source. Many standard voltage reference require an external wide bandwidth buffer to drive the reference input. The REF60xx has a built-in, wide-bandwidth driver, and is therefore optimized for driving SAR ADC reference inputs. The output filter network (R11 and C12) are the standard components recommended in the REF60xx for stable, low-noise operation.