Soon-Jyh Chang

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This paper presents a low-power 10-bit 50-MS/s successive approximation register (SAR) analog-to-digital converter (ADC) that uses a monotonic capacitor switching procedure. Compared to converters that use the conventional procedure, the average switching energy and total capacitance are reduced by about 81% and 50%, respectively. In the switching(More)
One of the most important issues during the analog layout phase is to achieve accurate capacitance ratios. However, systematic and random mismatches will affect the accuracy of the capacitance ratios. A common-centroid placement is helpful to reduce the systematic mismatch, but it still needs the property of high dispersion to reduce the random mismatch(More)
This paper reports a 10-bit 50MS/s SAR ADC with a set-and-down capacitor switching method. Compared to the conventional method, the average switching energy is reduced about 81%. At 50MS/s and 1.2V supply, the ADC consumes 0.92mW and achieves an SNDR of 52.78dB, resulting in an FOM of 52fJ/Conversion-step. Fabricated in a 0.13μm 1P8M CMOS technology, the(More)
Switched capacitors are commonly used in analog circuits to increase the accuracy of analog signal processing and lower power consumption. To take full advantage of switched capacitors, it is very important to achieve accurate capacitance ratios in the layout of the capacitor arrays, which are affected by systematic and random mismatches. A good capacitor(More)
In high-speed Flash analog-to-digital converters (ADCs), preamplifiers are often placed in front of a comparator to reduce metastability errors and enhance comparison speed. The accuracy of a Flash ADC is mainly limited by the random offsets of preamplifiers and comparators. This paper presents a 5-b Flash ADC with a digital random offset calibration(More)
In recent years, due to the improvements in CMOS technologies, medium resolution (8 to 10b) SAR ADCs have been able to achieve sampling rates of several tens of MS/s with excellent power efficiency and small area [1]-[4]. When the sampling rate increases, the SAR ADCs suffer from settling issues. In a typical 10b 100MS/s ADC, when the sampling settling(More)
This paper reports a subranged SAR ADC consisting of a 3.5-bit flash coarse ADC, a 6-bit SAR fine ADC, and a differential segmented capacitive DAC. The flash ADC controls thermometer MSBs of the DAC and SAR ADC controls the binary LSBs. The segmented DAC improves DNL during MSB transitions. The merged switching of MSB capacitors enhances operation speed.(More)
In this brief, a split-capacitor correlated double sampling (SC-CDS) technique is proposed to improve the performance of CDS. Using the proposed technique, low-gain operational amplifiers (op-amps) can be employed to implement a low-power pipelined analog-to-digital converter (ADC). A power-efficient class-AB pseudodifferential op-amp and its corresponding(More)
For battery-powered electronic products, one way to extend battery life is to use a versatile step-up/step-down DC-DC converter. A new versatile step-up/step-down switched-capacitor-based converter structure is proposed, and its efficiency is analyzed. In the step-down case, the efficiency is the same as, or even better than the efficiency of linear(More)