Research Article
Designing a High-Precision AC Current Source to Measure the nm-Scale Displacements in Mechanical Systems
Table 1
Performances of the source IQOA.
| f = 100 kHz,V1 − V2 = 500 mV | Zprobe,max = 2 MΩ | | Rprobe = 100 kΩ | Rprobe = 600 kΩ |
| Op amp | TL081 | OP249 | OPA657 | OPA655 | | ± 15 | ± 15 | ± 5 | ± 5 | | 7.5 | 7.5 | 2.5 | 2.5 | | 7.191 | 7.7 | 2.332 | 2.337 | | 7.9 | 8.6 | 4.5 | 4.476 | | 0.078 | 0.078 | 1020 | 144 | | 1.333 | 1.56 | 3.51 | 47.4 | | 1.335 | 1.568 | 1020 | 151.26 | (analytical model) | 19.7 | 18.4 | 0.028 | 0.14 | (PSPICE) | 24 | 20.5 | 0.04 | 0.11 |
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