So I'm still looking at topologies for an adjustable temperature stable current source/sink that track each other...I had an idea sort of like this:
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Sa?dl=0Two cross coupled Howland current pumps feed LM385 bandgap references...the two alternate polarity references would feed then two of the four inputs on another pair of Howland pumps (not shown) that generate the actual currents required, with a control voltage driving the other two appropriate inputs.
Is this topology worth pursuing?