I thought i would make a better version. Two current mirrors for supreme accuracy. Can buffer up to a 1 Mhz signal. Push pull style with the dual diode to eliminate transition distortion at the cost of efficiency. Works in a voltage range from 5 to 12v it seems.
If you like to know why i chose the values I did, keep reading.
10k -> speed > input current
20k -> Math I'll cover later 2 (10k)
1k -> High Current Output / Feedback control
2 PNPs source a max current of (Vin-Veb)/10k
2 NPNs sink a max current of (Vin-Vbe)/20k
1 NPN controls the push pull
2 diodes bring the push pull bases close to the same operating voltage
The final output is pretty obvious
Simple Math
PNP current mirror = 2 * NPN current mirror
(Vin-Veb)/R1 = 2 * (Vin-Vbe)/R2
R2 = 2*R1
This ensures that the differential pair stop sourcing current to the single NPN at the right time. Hence, source in -> split by 2 PNPs -> 1/2 current at NPN -> undesirable when in=out -> sink it to minimize output offset.
Sorry about the title. Normal is boring.
Have a nice day.
