| 摘要 |
The invention discloses a beam current measurement device with a new manner of subtracting the quiescent current through the emitter-follower transistors from the total current through these emitter-follower transistors to obtain a measurement of the actual beam current. Instead of two current mirrors, two folded cascode circuits are used. The measured beam current will then be the actual current plus an offset caused by the difference between the currents from the two current sources used with the folded cascodes. |
