8.2.2.2.1 ADC Reference Driver

Refer to the ADC Reference Driver section for a detailed design procedure for the ADC reference driver.

The application circuit in Figure 55 shows the schematic of a complete reference driver circuit that generates a voltage of 2.5-V dc using a single 5-V supply. This circuit is suitable to drive the reference of the ADS8350 at sampling rates up to 750 kSPS.

The 2.5-V reference voltage is generated by the high-precision, low-noise REF5025 circuit. The output broadband noise of the reference is heavily filtered by a low-pass filter with a 3-dB cutoff frequency of 160 Hz. The decoupling capacitor on each reference pin is selected to be 10 µF. The low output impedance, low noise, and fast settling time makes the OPA2350 a good choice for driving this high capacitive load.