After i finished reading this thread:
http://www.diyaudio.com/forums/solid-state/133018-current-mirror-discussion.html
This is one of awesome thread in our forum. Manythings i can learn.
Well, here are 2 of best current mirror which i found from this thread. They're simple but have very good performance.
So, in ''Glen current mirror'' (left). R1, R2 are degen resistors of transistor. Ib (Q1) + Ib (Q2) + I (R3) = Ie (Q3).
Please, reply me: How much current through R3 is enough?
In Hawksford cascoded symmetrical Vas, what's the kind is better? I have seen Wilson current mirror in Mongrel circuits, Symasym...
http://www.diyaudio.com/forums/solid-state/133018-current-mirror-discussion.html
This is one of awesome thread in our forum. Manythings i can learn.
Well, here are 2 of best current mirror which i found from this thread. They're simple but have very good performance.
So, in ''Glen current mirror'' (left). R1, R2 are degen resistors of transistor. Ib (Q1) + Ib (Q2) + I (R3) = Ie (Q3).
Please, reply me: How much current through R3 is enough?
In Hawksford cascoded symmetrical Vas, what's the kind is better? I have seen Wilson current mirror in Mongrel circuits, Symasym...
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adjust R3 until Iin exactly equals Iout
Measure Iin & Iout at the "top" end using precision matched resistors of a value that gets adequate resolution at the currents you are using.
eg. if feeding an LTP, the LTP degen resistors could be 100r and passing 1.5mA each. A 199.9mVdc DMM would read 150.xmVdc across the degen resistors. You can get current match approaching 0.1% if careful.
Then replace the Vr for a fixed value of R3.
Measure Iin & Iout at the "top" end using precision matched resistors of a value that gets adequate resolution at the currents you are using.
eg. if feeding an LTP, the LTP degen resistors could be 100r and passing 1.5mA each. A 199.9mVdc DMM would read 150.xmVdc across the degen resistors. You can get current match approaching 0.1% if careful.
Then replace the Vr for a fixed value of R3.
I' tested with a current mirror like here.
But i can't balancing current at 2 side of diff Vas to exactly. It's different a bit.
With improved Wilson current mirror, the current of two side seem very equal, to part per thousand of a Volt.
What's the best of CM for diff Vas?! Vas's used Hawksford cascode.
But i can't balancing current at 2 side of diff Vas to exactly. It's different a bit.
With improved Wilson current mirror, the current of two side seem very equal, to part per thousand of a Volt.
What's the best of CM for diff Vas?! Vas's used Hawksford cascode.
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