A 1280×1024-15μm CTIA ROIC for SWIR FPAs

This paper reports the development of a new SXGA format low-noise CTIA ROIC (MT12815CA-3G) suitable for mega-pixel SWIR InGaAs detector arrays for low-light imaging applications. MT12815CA-3G is the first mega-pixel standard ROIC product from Mikro-Tasarim, which is a fabless semiconductor company specialized in the development of ROICs and ASICs for visible and infrared hybrid imaging sensors. MT12815CA-3G is a low-noise snapshot mega-pixel CTIA ROIC, has a format of 1280 × 1024 (SXGA) and pixel pitch of 15 μm. MT12815CA-3G has been developed with the system-on-chip architecture in mind, where all the timing and biasing for this ROIC are generated on-chip without requiring any special external inputs. MT12815CA-3G is a highly configurable ROIC, where many of its features can be programmed through a 3-wire serial interface allowing on-the-fly configuration of many ROIC features. It performs snapshot operation both using Integrate-Then-Read (ITR) and Integrate-While-Read (IWR) modes. The CTIA type pixel input circuitry has 3 gain modes with programmable full-well-capacity (FWC) values of 10K e-, 20K e-, and 350K e- in the very high gain (VHG), high-gain (HG), and low-gain (LG) modes, respectively. MT12815CA-3G has an input referred noise level of less than 5 e- in the very high gain (VHG) mode, suitable for very low-noise SWIR imaging applications. MT12815CA-3G has 8 analog video outputs that can be programmed in 8, 4, or 2-output modes with a selectable analog reference for pseudo-differential operation. The ROIC runs at 10 MHz and supports frame rate values up to 55 fps in the 8-output mode. The integration time of the ROIC can be programmed up to 1s in steps of 0.1 μs. The ROIC uses 3.3 V and 1.8V supply voltages and dissipates less than 350 mW in the 4-output mode. MT12815CA-3G is fabricated using a modern mixed-signal CMOS process on 200 mm CMOS wafers, and there are 44 ROIC parts per wafer. The probe tests show that the die yield is higher than 70%, which corresponds to more than 30 working ROIC parts per wafer typically. MT12815CA-3G ROIC is available as tested wafers or dies, where a detailed test report and wafer map are provided for each wafer. A compact USB 3.0 based test camera and imaging software are also available for the customers to test and evaluate the imaging performance of SWIR sensors built using MT12815CA-3G ROICs. Mikro-Tasarim has also recently developed a programmable mixed-signal application specific integrated circuit (ASIC), called MTAS1410X8, which is designed to perform ROIC driving and digitization functions for ROICs with analog outputs, such as MT12815CA-3G and MT6415CA ROIC products of Mikro-Tasarim. MTAS1410X8 has 8 simultaneously working 14-bit analog-to-digital converters (ADCs) with integrated programmable gain amplifiers (PGAs), video input buffers, programmable controller, and high-speed digital video interface supporting various formats including Camera-Link. MT12815CA-3G ROIC together with MTAS1410X8 ASIC can be used to develop low-noise high-resolution SWIR imaging sensors with low power dissipation and reduced board area for the camera electronics.