Analog buffer/amplifier

[Gurjot Singh Bakhshi]

hi

i'm looking for i curcuit to act as a Analog buffer(some amplification
is acceptible)

my input signal is in the range of 0-300mV

i tried a common-source amplifier... but i dont get a linear transfer
characterists
(i tried many different resistance values but no change)

-gurjot

 

[Ban]

hi

i'm looking for i curcuit to act as a Analog buffer(some amplification
is acceptible)

my input signal is in the range of 0-300mV

i tried a common-source amplifier... but i dont get a linear transfer
characterists
(i tried many different resistance values but no change)

-gurjot

This is a buffer based on a differential amp. Very fast and little input
capacitance.

+-----------+-----o
| | +5V
.-. |
( I ) |
'-' |
| |/
+---------|
| |>
| |
+----)-----------+
| | |
|/ \| +-----o
o---| |-+-------+ Out
In |> <| |
| | |
+--+-+ |
| |
.-. .-.
( I ) ( I )
'-' '-'
| | -5V
+-------------+-----o
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de
view/fixed font
The current sources can be replaced by resistors, best is to use a
transistor array CA3127 or CA3086
http://www.intersil.com/data/mm/mm9/mm9701/mm9701.pdf for spice models
You can also use a opamp like LM324, but you need at least a small negative
voltage to get the O/P down to 0.
There are modern low offset or high input impedance opamps available which
will be much better, look at any semiconductor manufacturer.
+5V
o
|\|
o---------|+\ ___
| >--|___|-+---o
+-|-/ 100 |
| |/| |
| | |
+---)---------+
o
-5V