will i need amplifier in this case?


by samaaa
Tags: amplifier, case
samaaa
samaaa is offline
#1
Nov22-12, 03:01 PM
P: 48
Hi:

i have ADC(analog to digital) has a resolution 12 bits
and the input range is from +50mV to -50mV,
this men the precision is about 24uV

i want to use this ADC for a signal has Vp.p from 0.7mV to 1mV

so
can i use this ADC directly?or i must use amplifier ??
Phys.Org News Partner Engineering news on Phys.org
Fiber-optic microscope will help physicians detect cancer, diseases at early stages
Wind tunnel tests support improved aerodynamic design of B61-12 bomb
Smart sensor technology to combat indoor air pollution
Floid
Floid is offline
#2
Nov22-12, 05:50 PM
P: 235
You could just use the ADC but the problem is you only have 12 readings in that voltage range. If you need more resolution than that you need an amplifier.
samaaa
samaaa is offline
#3
Nov23-12, 03:20 AM
P: 48
Quote Quote by Floid View Post
You could just use the ADC but the problem is you only have 12 readings in that voltage range. If you need more resolution than that you need an amplifier.
no, i have 29 readings (from 700uV/24uV) .

Quote Quote by Floid View Post
If you need more resolution than that you need an amplifier.
how can i know what is the resolution i must use??
is there any equation to determine the resolution?

f95toli
f95toli is offline
#4
Nov23-12, 06:42 AM
Sci Advisor
PF Gold
f95toli's Avatar
P: 2,196

will i need amplifier in this case?


Quote Quote by samaaa View Post
no, i have 29 readings (from 700uV/24uV) .



how can i know what is the resolution i must use??
is there any equation to determine the resolution?
The resolution you need depends on what you are trying to measure, in some cases two values might be enough!

However, remember that the input noise of your ADC is also an issue, so in real life you will always need an amplifier.
Just get/build an amplifer with a gain of 50.
Floid
Floid is offline
#5
Nov23-12, 05:11 PM
P: 235
no, i have 29 readings (from 700uV/24uV) .
If you have a signal that you know ranges from 0.7mv to 1mv I would think that when measuring it your interest would be in the 300uV difference between the two.
samaaa
samaaa is offline
#6
Nov23-12, 05:18 PM
P: 48
Quote Quote by Floid View Post
If you have a signal that you know ranges from 0.7mv to 1mv I would think that when measuring it your interest would be in the 300uV difference between the two.
you dont understand me, the signal has Vp.p=700uV or 1 Vp.p(ECG signal)
the range may be from - 500uV to 500uV


Register to reply

Related Discussions
operation amplifier -- inverting amplifier Introductory Physics Homework 7
ce amplifier Electrical Engineering 1
"VOLTAGE-CONTROLLED AMPLIFIER". I am required to build a voltage-controlled amplifier Engineering, Comp Sci, & Technology Homework 3
klystrons which are used as amplifiers General Physics 6
Learn the general case first, or the special case first? General Math 6