The Zoom ADC: An Evolving Architecture

Zoom ADCs combine a coarse SAR ADC with a fine delta-sigma modulator (?SM) to efficiently obtain high energy efficiency and high dynamic range. This makes them well suited for use in various instrumentation and audio applications. However, zoom ADCs also have drawbacks. The use of over-ranging in their fine modulators may limit SNDR, large...

A Continuous-Time Zoom ADC for Audio Applications based on a High-Linearity OTA and a 4-bit SAR ADC

Analog-to-Digital Converters (ADCs) used in high fidelity audio applications require high linearity and a wide dynamic range (>100 dB). Moreover, for use in portable electronic devices such as smartphones, tablets, and hearing aids, these ADCs must also achieve high energy efficiency. This requirement of high linearity and high energy...

A CMOS Image Sensor with Thermal Sensing Capability and Column Zoom ADCs

This paper presents a CMOS image sensor (CIS) with a zoom ADC, to quantize in-pixel temperature sensors, as well as for faster readout speed of the image pixels while maintaining low quantization noise. The proposed 15 bit zoom ADC has a 4 bit Unit Capacitor Array (UCA) SAR and a 13 bit incremental 2^nd-order delta-sigma ADC (DSADC)...

A 6.3 μW 20 bit Incremental Zoom-ADC with 6 ppm INL and 1 μV Offset

A 20-bit incremental ADC for battery-powered sensor applications is presented. It is based on an energy-efficient zoom ADC architecture, which employs a coarse 6-bit SAR conversion followed by a fine 15-bit ΔΣ conversion. To further improve its energy efficiency, the ADC employs integrators based on cascoded dynamic inverters for extra gain and...