Abstract
This paper presents a novel high-gain transimpedance amplifier for flexible radiation sensing systems that can be used as large-area dosimeters. The circuit is implemented with Indium-Gallium-Zinc-Oxide (IGZO) thin-film-transistors (TFTs) and uses two stages for the amplification of the sensor signal (current). The first stage consists of cascode current mirrors with a diode connected load that performs current amplification and voltage conversion. Then, the first stage is followed by a voltage amplifier based on a positive feedback topology for gain enhancement. The proposed circuit converts nano-ampere (10nA) currents into hundreds of millivolts (280mV), showing a gain around 149dB and a power consumption of 0.45mW. The sensed radiation dose level, in voltage terms, can drive the next stages in the radiation sensing system, such as Analog to Digital Converters (ADCs). These radiation sensing devices can find potential applications in real-time, large area, flexible health and security systems.
| Original language | English |
|---|---|
| Pages (from-to) | 760-765 |
| Journal | IEEE Journal of the Electron Devices Society |
| Volume | 6 |
| DOIs | |
| Publication status | Published - 22 Jun 2018 |
Keywords
- a-IGZO TFT
- Amplifier
- Fabrication
- Gain
- Logic gates
- Positive feedback.
- Substrates
- Thin film transistors