AS3341D VCCS SOIC 16

AS3341 is a voltage controlled current source with internal temperature compensation and a matched pair of NPN transistors. Current source uses a temperature-compensated core of the VCO AS3340,
with an exponential and linear control scale.
  

The output current Iout- can be varied within a wide range from 50 nA to 500 µA. AS3341 also has a current output Iout + = 1 / 4Iout- which can be used to compensate for the linearity of the control
characteristic for a large output current Iout- 

https://www.alfarzpp.lv/eng/sc/AS3341.pdf