Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

ADC reference voltage - some questions

Status
Not open for further replies.
V

Vitamin-C

Member level 2
Joined
Apr 6, 2004
Messages
43
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Activity points
405
ADC reference voltage

HI,

Please see the graph.
It is a ADC inside a IC.

what is the purpose of putting a resistor 4k ohm
instead of biasing the ADC directly.

thx
Vita :)
 

ADC reference voltage

Hi. This resistor is used if you want to connect external reference to adc(more precision reference than internal).

Best Regards.
 

Re: ADC reference voltage

Hi....

This conection seems a bias wire for ADC. I mean, you put a 4k resistance in order to limit the flow current toward ADC. If there is a little flow of current, you may find almost same 2.5 V biasing ADC.
 

Re: ADC reference voltage

the 4Kohm resistor has 2 reasons:

1. it's the reason described by petarpav.
2. if you use internal ref, the 4Kohm resistor and external cap (common 100nF), make the noise rejection of internal refference. (work as RC integrator)
 

Re: ADC reference voltage

Hi. I think the resistor is connected to external reference voltage. The voltage is used to ADC converting.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top