Study On Key Technologies Of 640 × 512 Uncooled Infrared Focal Plane Array Roic

With the rapid development of infrared technology as well as the increasing attention on infrared technology at home and abroad in recent years, the uncooled infrared focal plane array has been widely used in both military and civilian fields. As an important part, the readout circuit has become the focus of the current worldwide research. The digital part of the readout circuit is of importance because of its control over the entire circuit.Based on the study of the development of infrared focal plane arrays at home and abroad, this paper has designed a digital circuit used for a 640 × 512 infrared focal plane array readout circuit. The digital circuit module is composed of sub-modules. Compared with a conventional digital circuit module, this digital circuit module here has an adjustable integration time and access time of the reference resistance, and the row select circuit has multiple modes, a power detection module and a test function module are also applied. By using Cadence on the Linux platform, we complete the design and simulation of the digital module to verify the feasibility of these functions. Here follows the main contents of this paper:1. We design a central timing control module with adjustable integration time and access time of the reference resistance, and this module can be controlled by external frame signal. By comparing the external frame signal or the value set in the circuit with the current output of the gray code counter, the time mentioned before can be adjusted.2. We design a row select module with multiple operating modes. this module can scan the pixel either from top to bottom or from bottom to top, and this module can also chooses to perform the scan with 512 rows or the half, namely 256 rows, and we can make the module to scan just the odd rows or just the even rows when the module operates with 256 rows.3. We also design a digital output module. Not like the common readout circuit with analog output, this module will convert the 13-bit current signal read from the column channel into a voltage signal, and then translate it to a binary data as an output.4. Other auxiliary modules are also designed, such as a power consumption detection module which can decide whether to stop the system according to the power, a test module which can verify the internal timing, and a parallel-to-serial converter module which converts a parallel signal to a serial signal.