# current source with high resistance load

what happen if the load is a high resistance ( let's say 100K )

• Then you get less than 1ma through it. – pjc50 Feb 4 '18 at 18:56
• What do you think? What's your hypothesis? – Harry Svensson Feb 4 '18 at 18:56
• Good question! It illustrates the need for specifying compliance when designing a current sink or source. – AlmostDone Feb 4 '18 at 19:17
• Comments are not for extended discussion; this conversation has been moved to chat. – clabacchio Feb 5 '18 at 7:45

The circuit, with exactly those component values comes from Art of Electronics, Horowitz & Hill. Read what they have to say about $V_{CEsat}$... the BJT cannot drag the collector down to $-90V$ in order to draw 1mA through 100k!