It has long been known that the simple combination of a depletion-mode MOSFET (and before these were available, a JFET) and a resistor made a simple, serviceable current source such as that seen on ...

An SCR topology transmogrifies into BJT two-wire precision current source with a self-resetting fault-current limiter.

CMOS current reference circuits play a critical role in modern integrated circuits by providing a stable and reproducible current source that remains unaffected by variations in supply voltage, ...