Design And Reserch On Terahertz Detector Readout Integrated Circuit

Terahertz detector has a spacious application prospection and practical value in many fields. Terahertz detector has become one of the main directions about scientific research. As a key technology of terahertz detector, researchers have paid attention to terahertz detector readout integrated circuit.Based on the research and development of the terahertz detectors in our laboratory, this paper completes the design of the 80×60 terahertz detector readout integrated circuit. This paper analyzes the circuit as a whole and adopts the module design concept. The structure and interconnection of the whole circuit is determined in this way. The following is the main content and innovation of this paper:1. This paper has finished the analysis of the whole circuit and the division of each function module, so as to accomplish the corresponding functions of each module. The digital circuit is the control section of the whole circuit. It will generate control signals to determine the work patterns of the array scanning circuit, integral circuit, sampling circuit and other circuits. The analog circuit is the signal processing section of the pixel unit. It consists of 80 column readout channels. Each channel contains integral circuit, sampling circuit and analog-to-digital converter. The channel can realize the readout and amplification of the signal with a high signal-to-noise ratio.2. This paper has finished the design of each unit circuit in the digital circuit and realized the corresponding control functions. The producing circuit of row selection control signal has accomplished with a method of module design in the digital circuit design process. Each module can produce three control signals. A row of pixels will be selected through the specific combination of the three control signals which are produced by the modules. The combination of the three control signals has diversification. As a result, it will produce different row selection patterns.3. This paper has finished the design of each unit circuit in the analog circuit and realized the signal processing of each pixel unit. In the analog circuit, a single slope analog-to-digital converter is used to improve the precision and speed. The output of the comparator which is in the single slope analog-to-digital converter is used to directly control the digital signal to be stored. There is no need to control the counting process of the counter. It helps to simplify the control process. The digital output signals of the single slope analog-to-digital converter are transmitted through the signal storage circuit. The signal storage circuit transforms the voltage signal into a current signal for transmission. The current signal has a strong anti-interference ability and low attenuation. Compared with the transmission of voltage signal, the transmission of current signal can reach the purpose of protecting signals.