I am using a Darlington Transistor (MFG6388GOS) as the controlling element for a Current Controller. The controller has an oscillation which I have narrowed down to the transistor switching.
I want the transistor to operate as a linear DC current amplifier but it just oscillates on-off, controlling the current with the duty cycle. The transistor has very high DC gain which may be part of the problem.
Is there a circuit configuration that will force the transistor to operate linearly?
If the high DC gain is the problem how would I figure out the correct amount of gain?
Yellow is the control signal to the transistor Base
Blue is Vce. ( low means transistor is sinking current, charging the inductor)
The ramping up-down on the control signal is due to the inductor charge-discharge time.
Any help is appreciated