TS3A24159: signal attenuation

Hi Yuan,

What is the load impedance that the Mux is feeding into? 

Ron will attenuate the signal, but how much depends on the loading conditions.

Please let me know, so I can look into this a little more, my first instinct is that it seems like a large voltage drop, but I can' t be sure until I know the loading conditions. 

Best,

Parker Dodson

Hi Parker,

here is the load's spec:

center frequency(MHz): 1.0±0.1

R0 under IMhz:100~500Ω

electrostatic capacity: 1200pf±20%

customer used to chose SN74CBTLV3257, didn't meet this kind of attenuation. but considering to size, they picked TS3A24159.

thank you!

Best regards,

Yuan

Hi Yuan,

Could you confirm the voltage drop across the switch, I understand that the load voltage is 160mV, but the level of attenuation seems way too high for this part with the indicated loading conditions that you mentioned.

Can you also confirm what supply rails are being used and the temperature that the system is supposed to operate in? 

Also is there anything else in the signal pathway that can attenuate the signal besides the mux? 

Please let me know so we can get to the bottom of this issue!

Best,

Parker Dodson

Below reply is from customer.

1. Confirm that the pressure drop at both ends of the switch is 60mV;

2. The whole test environment is from 15℃ to 20℃;

3. There are devices affecting amplitude attenuation in the whole link, but my question is why the amplitude attenuation of the cover switch is so large;

4. The circuit diagram I tested is as follows:

Working condition 1: The signal amplitude tested by the switch is 160mV

Working condition 2: When the signal switch is not used, the amplitude tested under the same conditions is 220mV

5. When SN74CBTLV3257 is used, there is no signal attenuation. Could you recommend a dual-channel signal switch with smaller package with similar performance to SN74? Thanks.