Digital to analogue conversion using direct interpolation

• Main Author: Hancock, M. P.
• Published: Swansea University 1987
• Subjects: 621.3
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.637215

Direct Interpolative Conversion (DIC) allows extra resolution to be added to a Digital to Analogue Converter (DAC) by operating it at higher speeds. No feedback is used for this system, and it is thought that the DIC process has greater practical potential for improving DAC performance than classical Noise Shaping and Oversampling techniques. This material reviews existing DIC analysis and extends this to include analysis of the practical limitations experienced with DIC DACs in high performance applications. A new technique using Constant Transition Array (CTA) Interpolation is introduced and described. This is shown to have greater resilience than conventional DIC schemes to DAC glitch defects. A second technique is proposed which uses a Digital Ramp Waveform to generate High Amplitude Interpolation. This is shown to be a method for enhancing DAC resolution and linearity. The hardware section describes a flexible and powerful DIC DAC evaluation system based on a programmable Interpolation Generator. The test and measurement section includes comprehensive investigations of DIC practical operation using the existing and the new techniques.