An All LTPS-TFT-Based Charge-Integrating Amplifier for Sensor-Array Readout Circuit on Flexible Substrate

Abstract

This paper presents the design of a readout circuit for charge-output sensor arrays integrated on flexible substrate. The Charge-Integrating-Amplifier is built with a current-output transimpedance amplifier that includes integrator function with reset. The Charge-Integrating-Amplifier has a fully differential internal topology, improving over single ended design, including the feedback amplifier implemented specifically as a Nauta-transconductor. The readout circuit has been manufactured in a 3µm LTPS process on foil and measured, achieving a bandwidth of 200kHz, operation at a 5V supply while consuming 586µW power and maintaining a maximum INL of 5%.

An Integrated Analog Front‐End System on Flexible Substrate for the Acquisition of Bio‐Potential Signals

“…The A d of an inverter amplifier is given by the product of the output resistance (r o ) of the load-transistor and the transconductance (g m ) of the driver-transistor. [37] Due to the lack of a viable technology for implementing a p-type metal-oxide TFT load, a relatively small r o limits the gain of an inverter amplifier based on unipolar TFTs. Capacitor-boosting [19,20] has been deployed to increase the r o by maintaining a relatively constant potential difference across the gate and source terminals of the load-TFT.…”

Thin-Film Transistor-Based Sensor Interface Circuits Enabling Distributed Local In-Module Solar Cell Temperature Monitoring

“…Presently in literature, little research has been conducted on the design of complex digital and analog blocks in LTPS technology. An analog buffer including a two stage OpAmp [22], [23], a class-B buffer with offset compensation [24], an OpAmp and comparator integrated in sigma-delta ADC [25], charge integrating amplifier for sensor array readout [26] and a high performance CMOS OpAmp [27] are notable works that provide insights into the current state-of-the-art in TFT mixed JSSC-23-0077 signal design. Considering the capability of LTPS technology for design of CMOS circuits especially when lower performance and cost of integrated circuits is expected, the gap between the capacity of this technology and actual realizations already published in literature highlights the importance of design and development in thin-film flexible circuits.…”