SBAS991 February 2021 ADC3663
Depending on desired input signal frequency range the THS4551 and THS4541 provide very good low power options to drive the ADC inputs. Table 9-3 provides a comparison between the THS4551 and THS4541 and the power consumption vs usable frequency trade off.
|DEVICE||CURRENT (IQ) PER CHANNEL||USABLE FREQUENCY RANGE|
|THS4561||0.8 mA||< 3 MHz|
|THS4551||1.4 mA||< 10 MHz|
|THS4541||10 mA||< 70 MHz|
The low pass filter design (topology, filter order) is driven by the application itself. However, when designing the low pass filter, the optimum load impedance for the amplifier should be taken into consideration as well. Between the low pass filter and the ADC input the sampling glitch filter needs to added as well as shown in Section 188.8.131.52.1. In this example the DC - 30 MHz glitch filter is selected.