A 16-bit serial analog-to-digital converter module with optical output

A high-resolution analog-to-digital converter (ADC) is needed for a variety of applications including readout electronics for infrared detectors in focal-plane arrays. The heat load of input/output (I/O) cables between the cryogenic environment (4 K) and room temperature dominates the power consumption of such an ADC. To reduce the number of outputs originating from the chip a 16-bit serial ADC has been developed. Further reduction of the heat load and more robust signal transmission can be achieved by extracting the serial ADC output using an optical fiber coupled to a laser diode. A compact module (5.75 in/spl times/2.1 in /spl times/1.1 in) has been prototyped to package the ADC chip and a laser diode.