Hello,
TI had suggested using the THS4513 (or THS4511) amp to drive an ADC. Our ADC selection is the TI ADS5463-SP. On page 17 of the ADS5463-SP data sheet an example circuit for using the THS4509 to drive the ADC is shown in figure 17.
Can the THS4509 in figure 17 of the ADS5463-SP data sheet be replaced with the THS4513-SP with no changes to resistor/capacitor values? (assuming same gain is needed)
In out application we will have a DC-coupled input to the THS4513 that is a 50ohm source. My understanding is that the 78.9ohm and 100ohm resistors on the input of the amp in figure 17 of the ADS5463-SP data sheet are there to match the impedance of the source..but 100||78.9 is only 44.1ohm so is my understanding wrong?
Lastly, a very similar circuit drawing is shown in figure 66 of the THS4513-SP data sheet for driving an ADC. However, the resistor values on the input of the amp are slightly different...69.8ohms show in THS4513-SP data sheet vs. 78.9ohm shown in ADS5463 data sheet....which value woudl be correct for using the THS4513-SP to drive the ADS5463-SP ADC?
Any help you can provide for properly driving the ADS5463-SP with the THS4513-SP is greatly appreciated.
Thanks,
Steve