| dc.description |
With the growing demand for portable/consumer electronics, such as digital
audio/video (AV), the downscaling of device dimensions, which enables the
integration of an increasing number of transistors in a single chip, is mandatory.
This trend also continuously pushes the power supply voltage down to reduce the
power consumption and improve the reliability of gate dielectrics. While the
reduction of power supply voltage is of great benefit to the essential digital blocks
in the system like data storage and digital signal processing, it makes it hard to
operate the important and indispensable analog building blocks such as data
converters and drivers.
In this thesis, the novel structures for the low-voltage digital-to-analog
converter (DAC) and analog-to-digital converter (ADC) are presented. The
research contributions of this work include (1) a sub-1V audio [delta sigma] DAC with one
opamp used per channel to implement D/A conversion, 1st-order FIR and 2ndorder
IIR filtering, as well as power amplification for the headphone, (2) a sub-1V
pipelined ADC with the novel MDAC based on a low-voltage track-and-hold
amplifier. Two prototypes, one is a 0.8V, 88dB dual-channel audio [delta sigma] DAC with
headphone driver, the other one is a 0.8V, 10-bit, 10MS/s pipelined ADC were
fabricated to verify the functionality of the proposed structures in standard CMOS
processes. |
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