A high-speed NMOS A/D converter with a current source array

A high-speed MOS analog-to-digital (A/D) converter has been designed and fabricated in a standard single channel metal-gate enhancement/depletion MOS process. The use of current switching performs a conversion time of 13.2 /spl mu/s at a resolution of 8 bits. To replace the resistance ladder a binary weighted current source array has been implemented which consists of MOS transistors. The test circuit requires 4 mm/SUP 2/ including all analog circuit functions without the successive approximation register.