TLV4062: TLV4062 parallel and as Time Multiplexing

Hale

Looks like you accidentally typed the wrong part number in the title. I can move your post Tuesday or you can repost so GPAMPs team will receive sooner. 
Chuck

Hale Tan said:

time-to-time multiplexing

Hale, can you explain this concept more clearly? Is the sum of both PD not desired?

Hi Ron,

It works like U1 has an input signal in t0~t1 and at the same time U2 doesn't has input signal; then U2 works in t1~t2 and at the same time U1 doesn't work. So we need to make sure, if U1 is working, U2 is still connected with the signal chain although there is no signal. Will there be an influence on this design with a non-signal device. Could you help make some experiment or simulation to verify the circuit feasibility?

Hale,

This circuit topology will simply sum the two input signals. C7 and C8 are not needed. R8 and R9 values are rather small.

What is the desired bandwidth min and max? Can the last stage be inverting so the summing junction is a virtual ground instead of an average (a polite fight)?

Ron,

What is the recommendation of R8 and R9? And C7, C8 is used for filter, why do you think they are not useful?

The input signal frequency is 1.5K and Vpp is sine 0.00002, you can get the requirement form the above picture.

Ron Michallick said:

Can the last stage be inverting so the summing junction is a virtual ground instead of an average (a polite fight)?

As for the last question, I don't understand. And could you help make a simulation for us to check this solution feasibility?

Hale,

Band width is 88Hz to 16kHz.  The low end set how long the transients lasts.

Last stage is inverting, in contrast to original schematic. 

Note: R6 was added R6 as a part of IG1 and SW1 to delay the sine wave. IG1 is ideal so R6 is no effect to this ideal source. Do not add R6 to real schematic.

Hi Ron,

What simulation do you use? And could you help share it with us? We wan to use TINA to simulate.

Hale,

This is Tina.

TIA summer.TSC

Ron,

Thanks for your help. Could you help explain the reason about adjusting R8, C4,C7? 

Hale,

Those components can create moderate current flow that the other input amplifier has to cancel. That seems totally unnecessary (and unhelpful) to me.