HI,
I am building an adjustable bench P.S.U. for home use (I could buy one, but this way is more fun).
The final regulator in my P.S.U. is an LTC3080.
The regulator requires 0.5mA minimum load to work correctly.
So I thought of using a current source to provide that minimum load.
The obvious choice is a shunt current source connected across the output.
But I have hit a limitation in the fact that these current sources need a minimum supply voltage to operate.
The best I could find is a LM334Z and it requires a minimum voltage of 0.8V to operate correctly.
I want my P.S.U. to be able to regulate correctly below that 0.8V, down-to few mA, so the output voltage does not float, when there is no load.
I have not been able to come-up with a solution to this problem.
I may have to live with it! But from an engineering point of view I would like to know how to solve this problem.
Regards
Francesco
I am building an adjustable bench P.S.U. for home use (I could buy one, but this way is more fun).
The final regulator in my P.S.U. is an LTC3080.
The regulator requires 0.5mA minimum load to work correctly.
So I thought of using a current source to provide that minimum load.
The obvious choice is a shunt current source connected across the output.
But I have hit a limitation in the fact that these current sources need a minimum supply voltage to operate.
The best I could find is a LM334Z and it requires a minimum voltage of 0.8V to operate correctly.
I want my P.S.U. to be able to regulate correctly below that 0.8V, down-to few mA, so the output voltage does not float, when there is no load.
I have not been able to come-up with a solution to this problem.
I may have to live with it! But from an engineering point of view I would like to know how to solve this problem.
Regards
Francesco