Virtual Ground.

The common terminal goes to a ground or a negative supply, the input terminal goes to a positive voltage supply, so that the total voltage from input to common is less than the 2425s rating input voltage rating. Then you get +2.5V on the output terminal w.r.t. the common terminal. It's just a precision 3-terminal regulator. The 2.5 V unit would usually be used in a system with a single 5 V supply, to get a virtual ground for analog circuits at V+ / 2.

-- John

This may help:

Richard

Your post is a bit rambling, but I havent read the TI doc, but the main difference is that the VG will split the supply by two, so if the supply drifts a bit, eg a car battery, it will always be 1/2 the supply. With a zenered VG it will remain at the Vz, so as the supply varies, the psuedo + - supplies will not be symetrical

hope this helps

martin

The TLE2425 is basically a 2.5 volt voltage regulator - the input is

The idea of the thing is that you can operate your analog circuit on a single +5V supply (just +5 and ground), and the TLC2425 will produce a stable +2.5 volts that will connect to the points in your circuit that would go to ground if you were using a bipolar supply (like +5 and

-5).

It is IMHO a pretty useless part with an awful lot of noise. You can configure almost any opamp to sink and source 20mA and a voltage reference to do the same. Only certain ADCs with a single reference and low speed can make advantage of this IC, for opamps it is better to just use a voltage divider for the reference voltage. If you had read the datasheet, you would know that it is powered fro either the +5V rail or higher.

thanks, that cleared it up, i also found a sight that was helpfull.

i understand the practice of doing so,i just have never seen that done in a single package with no components like that.