Delta-Sigma Digital-to-Time Converter for Band-Select Spread Spectrum Clock

2015 ◽  
Vol 643 ◽  
pp. 79-91 ◽  
Author(s):  
Ramin Khatami ◽  
Haruo Kobayashi ◽  
Yasunori Kobori

This paper proposes an innovative method of converting digital signal to time-domain analog signal, which fully enjoys robustness and digital circuit friendliness. This technique utilizes a digital delta-sigma ( ) modulator following a digital-to-time converter (DTC) circuit with various modulation methods. As an application of the proposed method, novel spreadspectrum clock generation (SSCG) algorithms (such as for DC-DC converters) have been investigated which can select the noise spectrum spread bands; e.g., they can exclude the noisespectrum spread in AM, FM radio bands. The proposed circuit takes advantage of digital technology, which is simple, fast (reachable at high clock frequency) and flexible (programmable).

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1619 ◽  
Author(s):  
Mauro D’Arco ◽  
Ettore Napoli ◽  
Efstratios Zacharelos

Fine resolution selection of the sample rate is not available in digital storage oscilloscopes (DSOs), so the user has to rely on offline processing to cope with such need. The paper first discusses digital signal processing based methods that allow changing the sampling rate by means of digital resampling approaches. Then, it proposes a digital circuit that, if included in the acquisition channel of a digital storage oscilloscope, between the internal analog-to-digital converter (ADC) and the acquisition memory, allows the user to select any sampling rate lower than the maximum one with fine resolution. The circuit relies both on the use of a short digital filter with dynamically generated coefficients and on a suitable memory management strategy. The output samples produced by the digital circuit are characterized by a sampling rate that can be incoherent with the clock frequency regulating the memory access. Both a field programmable gate array (FPGA) implementation and an application specific integrated circuit (ASIC) design of the proposed circuit are evaluated.


2021 ◽  
Vol 11 (1) ◽  
pp. 429
Author(s):  
Min-Su Kim ◽  
Youngoo Yang ◽  
Hyungmo Koo ◽  
Hansik Oh

To improve the performance of analog, RF, and digital integrated circuits, the cutting-edge advanced CMOS technology has been widely utilized. We successfully designed and implemented a high-speed and low-power serial-to-parallel (S2P) converter for 5G applications based on the 28 nm CMOS technology. It can update data easily and quickly using the proposed address allocation method. To verify the performances, an embedded system (NI-FPGA) for fast clock generation on the evaluation board level was also used. The proposed S2P converter circuit shows extremely low power consumption of 28.1 uW at 0.91 V with a core die area of 60 × 60 μm2 and operates successfully over a wide clock frequency range from 5 M to 40 MHz.


1995 ◽  
Vol 06 (01) ◽  
pp. 163-210 ◽  
Author(s):  
STEPHEN I. LONG

The performance of high speed digital integrated circuits, defined here as those requiring operation at high clock frequency, is generally more sensitive to material properties and process techniques than ICs used at lower frequencies. Obtaining high speed and low power concurrently is especially challenging. Circuit architectures must be selected for the device and application appropriately. This paper presents simple models for high speed digital IC performance and applies these to the FET and bipolar transistor. Heterojunction devices are compared with those using single or binary materials. Circuits for high speed SSI and low power VLSI applications are described, and their performance is surveyed.


Electronics ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 482
Author(s):  
Mangi Han ◽  
Youngmin Kim

In this study, we implemented a high-performance multichannel repeater, both for FM and T-Digital Multimedia Broadcasting (DMB) signals using a Field Programmable Gate Array (FPGA). In a system for providing services using wireless communication, a radio-shaded area is inevitably generated due to various obstacles. Thus, an electronic device that receives weak or low-level signals and retransmits them at a higher level is crucial. In addition, parallel implementation of digital filters and gain controllers is necessary for a multichannel repeater. When power level is too low or too high, the repeater is required to compensate the power level and ensure a stable signal. However, analog- and software-based repeaters are expensive and they are difficult to install. They also cannot effectively process multichannel in parallel. The proposed system exploits various digital signal-processing algorithms, which include modulation, demodulation, Cascaded Integrator Comb (CIC) filters, Finite Impulse Response (FIR) filters, Interpolated Second Ordered Polynomials (ISOP) filters, and Automatic Gain Controllers (AGCs). The newly proposed AGC is more efficient than others in terms of computation amount and throughput. The designed digital circuit was implemented by using Verilog HDL, and tested using a Xilinx Kintex 7 device. As a result, the proposed repeater can simultaneously handle 40 FM channels and 6 DMB channels in parallel. Output power level is also always maintained by the AGC.


Author(s):  
Markeljan Fishta ◽  
Franco Fiori

Abstract$$\varDelta \varSigma $$ Δ Σ analog-to-digital converters (ADCs) are largely used in sensor acquisition applications. In the last few years, standalone $$\varDelta \varSigma $$ Δ Σ modulators have become increasingly available as off-the-shelf parts. To build a complete ADC, a standalone modulator has to be paired with some advanced elaboration unit, such as a field programmable gate array (FPGA) or a digital signal processor (DSP), which is needed for the implementation of the decimation filter. This work investigates the use of low-cost, general-purpose microcontrollers for the decimation of $$\varDelta \varSigma $$ Δ Σ -modulated signals. The main challenge is given by the clock frequency of the modulator, which can be in the range of a few $$\hbox {MHz}$$ MHz . The proposed technique deals with this limitation by employing two serial peripheral interface (SPI) modules in a time-interleaved configuration. This approach allows for continuous acquisition and elaboration of relatively high-speed, digital signals. The technique has been applied to a case study, and a data conversion system has been practically realized. The performance of the proposed filter is compared to that of a digital filter, present on board a commercial microcontroller, and the results of experimental tests are provided.


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