Bipolar Grizzly Bear

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.

published 9 years ago