Original question:
Hi team,
Customer hopes to use it output analog sine wave.
Input would be 1Vpp(S1) and 3Vpp(S2) 100kHz sine wave.
They need the output be totally the same as S1 or S2.
Could TMUX1574 support this function?
If not, which part do you recommend?
Thank you.
Best Regards,
Cindy
Hi Cindy,
There will be some signal attenuation but not much:
At 3.3V supplies you can use the typical response curves shown above (found in the datasheet):
for a 1Vp-p signal (0V to 1V) @ 100KHz:
At Room Temp: On Resistance increases with input voltage from ~1.1Ohms to ~1.2 Ohms over the input voltage range. With the 204 ohm load the sine wave received will have lost between 0.54% and 0.58% of the input signal. There is some very slight distortion that can occur due the on resistance being non-linear. However As you can see the difference of attenuation between min and max is only at 0.04% so it is very low.
At Max Temp: On Resistance increases with input voltage from ~1.6Ohms to ~1.7 Ohms over the input voltage range based on the above graph. With the 204 Ohm load the sine wave received will have lost between 0.78% and 0.83%. Once again from the graphs this will cause very little change to the sine wave going through the device.
For a 3Vp-p signal (0V to 3V) @ 100KHz:
At Room Temp: On Resistance increases with input voltage from ~1.1Ohms to ~1.4 Ohms over the input voltage range. With the 204 ohm load the sine wave received will have lost between 0.54% and 0.68% of the input signal. The difference in attenuation over the range is 0.14% so it is still very low, and very small changes in the attenuation lead to lower distortion
At Max Temp: On Resistance increases with input voltage from ~1.6Ohms to ~2 Ohms over the input voltage range based on the above graph. With the 204 Ohm load the sine wave received will have lost between 0.78% and 0.97%. Once again from the graphs this will cause very little change to the sine wave going through the device as the range of differences in attenuation is only 0.19%.
However are some rare edge cases that we do spec for, and while the vast majority of operating scenarios are going to relate to the cases I described above we do have some absolute worst case corners
Worst Case Attenuation - RON = 4.5 Ohms -> Attenuation = 4.5/208.5 = 2.16% signal loss with 204 Ohm Load
Worst Case RON Flatness = 1.8 Ohms -> Difference in Attenuation -> 0.87% difference at worst case Flatness (Still < 1%, good for low distortion)
So in short, in most use cases you are looking at a attenuation of < 1% and it will introduce very little distortion as typically the difference in attenuation seen by the signal is going to be <0.2% in most cases. If the unlikely event occurs and worst case device performance is seen the attenuation should still be low and the difference in attenuation is going to be < 1% which mean it won't add too much distortion to the system.
This switch has a lower R_on and low Capacitance which makes it a good fit for low distortion/ low attenuation designs.
If you have any other questions please let me know!
Best,
Parker Dodson
