Development of an ASIC for the readout and control of near-infrared large array detectors

The article describes the near infrared readout and controller ASIC (NIRCA) developed by Integrated Detector Electronics AS (IDEAS). The project aims at future astronomical science and Earth observation missions, where the ASIC will be used with image sensors based on mercury cadmium telluride (HgCdTe, or MCT). NIRCA is designed to operate from cryogenic temperatures (77 K) to higher than room temperature (328 K) and in a high radiation environment (LET > 60 MeVcm2/mg). The ASIC connects to the readout integrated circuit (ROIC) and delivers fully digitized data via serial digital output. The ASIC contains an analogue front-end (AFE) with 4 analogue-to-digital converters (ADCs) and programmable gain amplifiers with offset adjustment. The ADCs have a differential input swing of ±2 V, 12-bit resolution, and a maximum sample rate of 3 MSps. The ASIC contains a programmable sequencer (microcontroller) to generate up to 40 digital signals for the ROIC and to control the analogue front-end and DACs on the chip. The ASIC has two power supply voltage regulators that provide the ROIC with 1.8 V and 3.3 V, and programmable 10-bit DACs to generate 16 independent reference and bias voltages from 0.3 V to 3 V. In addition NIRCA allows one to read 8 external digital signals, and monitor external and internal analogue signals including onchip temperature. NIRCA can be programmed and controlled via SPI interface for all internal functions and allows data forwarding from and to the ROIC SPI interface.