A 1-G?? CMOS transimpedance amplifier (TIA) suitable for processing sub-nA-level currents in electrochemical biosensor signal-acquisition circuits is presented. Use of a two-stage active transconductor provides resistive feedback in place of a large-area linear resistor. The TIA feedback loop is engineered to suppress output offset caused by DC input leakage currents of ??0.9 nA. A mechanism to tune the low-frequency cutoff of the TIA from 0.7 Hz to 500 Hz is implemented which permits operation under variable environmental conditions. Simulated and experimental results from a custom TIA fabricated in a 3.3-V 0.35-??m CMOS process are presented.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OWTU.10012/8147 |
| Date | 20 January 2015 |
| Creators | Ibrahim, Mark |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Thesis or Dissertation |
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