So I need a component which will have a flat сurrent–voltage characteristic (constant current in a wide voltage range).
Initially I was intended to ask a general question: what kind of the device can do this function. However some of commentators wished more details so I'm putting them into the question:
For the moment I need that the device can be supplied with voltage as low as 1V (I wish it could be even lower) and drive current in scale of tens of microAmsp. The precision of the current should be something within 10% in range of voltage between 1 and 10V and in typical industrial temperature range.