bandgap isolation in adc

Hi, all,

How to isolate the bandgap output from the nodes which need bandgap voltage in adc? Directly connect, output of bandgap will degrade.
Your help is my hope. Thx!

Put a buffer on bandgap output

Humungus said:

Put a buffer on bandgap output

Click to expand...

There are three reference voltages that means each reference voltage output need one buffer?Thx!

Unless you can multiplex the reference voltages, you will need one buffer per reference output. No magic solution;-)

philipwang said:

Humungus said:

Put a buffer on bandgap output

Click to expand...

There are three reference voltages that means each reference voltage output need one buffer?Thx!

Click to expand...

It depond on you system requirement.
1. add three buffer
2. add a buffer in the middle, while the low,middle,high are serial by res

For example, a 2v voltage had been supplied through bandgap, 1.8v, 1.6v, 1.4v and 1.2v reference voltages are requirested, from 2v node to gnd 5 resistors are serial, then from 4 node four reference voltages are generated, so 4 buffers need to be connected to the 4 node respectively befor they supply outside circuit, right? Thx!

sunking said:

philipwang said:

Humungus said:

Put a buffer on bandgap output

Click to expand...

There are three reference voltages that means each reference voltage output need one buffer?Thx!

Click to expand...

It depond on you system requirement.
1. add three buffer
2. add a buffer in the middle, while the low,middle,high are serial by res

Click to expand...

Added after 6 minutes:

Another problem, what characters does the buffer need? to need the accurate of reference voltage maybe a 60db amplifier is needed, right?

Humungus said:

Unless you can multiplex the reference voltages, you will need one buffer per reference output. No magic solution;-)

Click to expand...