Current-Steering Power DAC with improved Dynamic Range Utilizing MASH
Modulation Techniques
Abstract
This paper presents the design and realization of a
15-bit-input-Digital-to-Analog Converter (DAC) that leverages the
advantages of both Delta-Sigma Modulation (DSM) and Current-Steering DAC
(CS-DACs) architectures to achieve superior dynamic performance. The
proposed DAC design partitions the digital input signal into two
segments: The 7- least significant bits (LSBs) are processed through a
Delta-Sigma Modulator (DSM) based on a 3-stage cascaded MASH
(Multi-stage Noise Shaping) structure, generating 3-bit modulated
output. The 8- most significant bits (MSBs) are decoded utilizing a
thermometer coding scheme, yielding 31 control signals for 8x current
sources and 7 control signals for 1x current sources. By integrating the
DSM DAC with a CS-DAC, the proposed architecture realized a 8-bit DAC,
achieving significant improvements in dynamic performance compared to a
conventional 8-bit CS-DAC. The results demonstrate enhanced resolution
and reduced noise, underscoring the efficacy of the combined approach in
addressing the limitations inherent in standalone Current-Steering DACs.