Variation and mismatch effects of the low-temperature poly-Si TFTs on the circuit for the X-ray active matrix sensor

Ya-Hsiang Tai*, Shih Che Huang, Ko Ching Su, Chen Yeh Tseng

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

The application of the capability of low-temperature poly-Si TFT circuits for high resolution X-ray active matrix sensor is explored. The integration of poly-Si TFT circuits on the glass enables an easy connection for the sensor array with fine pixel pitch. A novel charge sensitive amplifier circuit employing poly-Si TFTs is proposed for the readout system of the active matrix sensor. It can considerably increase the circuit's immunity to the unavoidable threshold voltage variations of the poly-Si TFTs. The VTH mismatch effect of the TFTs, which results in the offset voltage of the charge amplifier, can also be suppressed by the proposed circuit. However, the noise arisen from the VTH mismatch can be even larger than that from the VTH variation after compensation. It reflects that, for higher bit digital X-ray image sensors, the mismatch effect of the devices must be properly taken into consideration.

Original languageEnglish
Pages (from-to)649-656
Number of pages8
JournalSolid-State Electronics
Volume52
Issue number5
DOIs
StatePublished - 1 May 2008

Keywords

  • Charge sensitive amplifier
  • Poly-Si TFTs
  • X-ray active matrix sensor

Fingerprint Dive into the research topics of 'Variation and mismatch effects of the low-temperature poly-Si TFTs on the circuit for the X-ray active matrix sensor'. Together they form a unique fingerprint.

Cite this