CMOS:How to change constant current source to a square current source

[6716914]

I have a CMOS accurate constant current source (1mA), now I wanna it be a square wave, maybe 50% duty is fine, what kind of CMOS circuit I can use to change it ?

 

[dick_freebird]

There are several ways to make a switched current mirror,
which one you'd choose depends on accuracy and settling
time required, mostly.

You could have a simple current mirror and jerk its gate
rail between active and shunted. This will have a large
swing driven by a low current, neither spectacularly
accurate nor fast.

You could have a cascode mirror and inject a current
into the mid-point that exceeds the set-current, which
is basically source-steering; that node is low impedance
and the signal swing can be small, if controlled well.

You could use a simple diff pair attached to the present
source (or sink), and this can be steered by a few
hundred mV swing.

 

[6716914]

I think you misunderstand what I mean, I dont wanna change my current source's circuit, I hope I can change the output signal of the source which is flat and constant to a square wave.

 

[dick_freebird]

So you want to change the result without changing the
method? Good luck with that.