Part Number: THS3217
I have a 275MSPS high speed DAC (DAC5672).
usually the DAC driver is a difference amplifier with two Rt resistors at the output current of the DAC as shown below:
I want to maximize the CMRR and Linearity.
if I want to maximize the CMRR, I should minimize the miss-match between the resistors in the difference amplifier. I have found some resistor networks like below:
but the size is as shown below:
another option is THS3217, there are two unity gain buffers at the input:
now the advantage is use of two 49.9 Ohm resistors as Rt, (I don't need the Power Amp)
my signal should be 2Vpp and the HD2 should be better than 90dB.
now which option do you recommend me?
Jacob Freet High Speed Amplifiers
In reply to Jacob%20Freet:
Thanks for your attentions :) I should keep the SFDR around 90dB and SNR>70dB within 10MHz. bcoz I want to keep the maximum performance of the DAC. *actually THS3217 has all parts of the first solution in itself. *with the first solution I have concern about the size of resistor network. *what would have happened if THS3217 didn't have two unity gain buffers? ( I guess some reflections and mismatch issues) *I don't need the Power Amplifier, can I realize THS3217 with two ultra low distortion buffers and one difference amplifier? I think the difference amplifier with +2 of a gain causes distortion in THS3217.
another question is:
I have found a note in THS3217's datasheet.
at page 24:
you have used a function generator to produce a pure signal. but the purity is 100dB :) I'm wondered how did you produce it? your function generator is special?
In reply to xyz xyz:
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