bandgap isolation in adc

[philipwang]

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!

 

[Humungus]

Put a buffer on bandgap output

 

[philipwang]

Put a buffer on bandgap output

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

 

[Humungus]

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

 

[sunking]

Put a buffer on bandgap output

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

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

 

[philipwang]

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!

Put a buffer on bandgap output

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

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

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?

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