A Beyond-the-Rails Hybrid Delta-Sigma Modulator for Audio Applications

This thesis describes the design of a 3rd order 1-bit delta-sigma modulator whose input-signal range (0 to 1.95V) exceeds its supply voltage (1.2V). By using a passive input stage and a single-OTA resonator, this beyond-the-rails modulator realizes a 3rd order loop filter with only two amplifiers instead of the usual three and thus achieves...

Hybrid Beamforming Zero-Crossing-Based Noise-Shaping SAR ADC for Ultrasound Imaging

In ultrasound imaging systems, a charge-sharing successive-approximation-register (SAR) ADC has benefits over a charge-redistribution SAR because the charge-sharing SAR is organically compatible with the subarray beamformer which is deployed to reduce the large channel count. Besides, the noise-shaping (NS) SAR is a promising candidate for...

Beamforming Noise-Shaping SAR ADC for 3-D Ultrasound Imaging

3-D ultrasound imaging using a 2-D array provides much more information about our body than conventional 2-D imaging. However, due to the large number of elements in a 2-D array, channel count reduction is required and the power and area budget for each element is limited. It is quite challenging to design an ultrasound interface circuit with...

A 590 μw, 106.6 dB SNDR, 24 kHz BW Continuous-Time Zoom ADC with a Noise-Shaping 4-bit SAR ADC

This paper presents a continuous-Time zoom ADC for audio applications. It combines a 4-bit noise-shaping coarse SAR ADC and a fine delta-sigma modulator with a tail-resistor linearized OTA for improved linearity, energy efficiency, and handling of out-of-band interferers compared to previous designs. In 160 nm CMOS, the prototype chip...

Universal Digital Class D Current Driver for Inductive Motors

This thesis discusses the basic architecture, design details, circuit implementation, and measurements of a digital class D current driver.<br/>The driver contains two main parts: a digital control loop and analog circuits.<br/>Parts of the important part in the digital control loop contain noise shaper, plant compensator, and cable capacitance...

A Fully-Passive Noise-Shaping SAR for use in a Zoom ADC

The ΔΣ analog-to-digital converter (ADC) is widely used in audio applications for its high resolution. However, it is less energy efficient compared to Nyquist Rate ADCs. The growing demand for portable and wearable devices poses a more stringent power-efficient requirement on the audio system, and the traditional ADCs architecture is hard to...

An Error Feedback Noise Shaping SAR ADC

Analog-to-digital converters are important blocks in any electronic system which act as a bridge between analog signals and digital processors. The conventional SAR ADC employs a binary search algorithm and has emerged as the most suitable solution for low-power applications, due to its excellent power efficiency. The proposed ADC architecture...

An On-Chip Self-Characterization of a Digital-to-Time Converter by Embedding it in a First-Order ΔΣ Loop

To characterize an on-chip programmable delay in a low-cost and high-resolution manner, a built-in self-test based on a first-order &amp;#x0394;&amp;#x03A3; time-to-digital converter with self-calibration is proposed and implemented in TSMC 28-nm CMOS. The system is self-contained, and only one digital clock is needed for the measurements. A...

Numerical Model of an Injection-Locked Wideband Frequency Modulator for Polar Transmitters

We present a numerical model of a wideband injection-locked frequency modulator used in a polar transmitter for 3G cellular radio application. At the heart of the system is a self-injection-locked oscillator with a programmable linear tuning range of up to 200 MHz at 4-GHz oscillation frequency. The oscillator is injection locked to a time...

Reduced sample rate sigma-delta modulation

On smart dither by absolute one-bit coding for noise-shaped PCM