公开(公告)号：US20200295977A1

公开(公告)日：2020-09-17

申请号：US16833177

申请日：2020-03-27

Applicant: Analog Devices Global Unlimited Company

Inventor： Hajime SHIBATA ,  Brian HOLFORD ,  Trevor Clifford CALDWELL ,  Siddharth DEVARAJAN

IPC: H04L25/06 ,  H04L12/26 ,  H04L27/156 ,  H03M1/12 ,  G11C27/02 ,  G11C7/22 ,  G01R13/34

Abstract: A continuous-time sampler has series-connected delay lines with intermediate output taps between the delay lines. Signal from an output tap can be buffered by an optional voltage buffer for performance. A corresponding controlled switch is provided with each output tap to connect the output tap to an output of the continuous-time sampler. The delay lines store a continuous-time input signal waveform within the propagation delays. Controlling the switches corresponding to the output taps with pulses that match the propagation delays can yield a same input signal value at the output. The continuous-time sampler effectively “holds” or provides the input signal value at the output for further processing without requiring switched-capacitor circuits that sample the input signal value onto some capacitor. In some cases, the continuous-time sampler can be a recursively-connected delay line. The continuous-time sampler can be used as the front end sampler in a variety of analog-to-digital converters.

公开(公告)号：US20170179975A1

公开(公告)日：2017-06-22

申请号：US15360984

申请日：2016-11-23

Applicant: Analog Devices Global

Inventor： YUNZHI DONG ,  Hajime SHIBATA ,  Trevor Clifford CALDWELL ,  Zhao LI ,  Jialin ZHAO ,  Jose Barreiro SILVA

IPC: H03M3/00

CPC classification number: H03M3/422 ,  H03M1/361 ,  H03M3/322 ,  H03M3/344 ,  H03M3/378 ,  H03M3/388 ,  H03M3/414 ,  H03M3/436 ,  H03M3/464

Abstract: For continuous-time multi-stage noise shaping analog to digital converters (CT MASH ADCs), quantization noise cancellation often requires estimation of transfer functions, e.g., a noise transfer function of the front end modulator. To estimate the noise transfer function, a dither signal can be injected in the front end modulator. However, it is not trivial how the dither signal can be injected, since the dither signal can potentially leak to the back end modulator and cause overall noise degradation. To address some of these issues, the dither signal is injected post the flash analog to digital converter (ADC) of the front end modulator. Furthermore, dummy comparator structures can be used to synchronize the dither with the quantization noise of the targeted flash ADC.

公开(公告)号：US20170179970A1

公开(公告)日：2017-06-22

申请号：US15369175

申请日：2016-12-05

Applicant: Analog Devices Global

Inventor： ZHAO LI ,  Hajime SHIBATA ,  Trevor Clifford CALDWELL ,  Yunzhi DONG ,  Jialin ZHAO ,  Richard E. SCHREIER ,  Victor KOZLOV ,  David Nelson ALLDRED ,  Prawal Man SHRESTHA

IPC: H03M1/10 ,  H03M3/00 ,  H03M1/06 ,  H03M1/34 ,  H03M1/12

CPC classification number: H03M1/1009 ,  H03M1/0626 ,  H03M1/066 ,  H03M1/1245 ,  H03M1/34 ,  H03M3/388 ,  H03M3/422

Abstract: An analog-to-digital converter (ADC) is a device that can include a reference shuffler and a loop filter. An ADC can achieve better performance with incremental adjustment of a pointer of the reference shuffler, changing coefficients of the loop filter, and storing calibration codes of the ADC in a non-volatile memory. By incrementally adjusting a pointer of the reference shuffler, a calibration can be performed more efficiently than with a random adjustment of the pointer. By temporarily changing the loop filter coefficients, a greater amount of activity can be introduced into the loop filter. This activity can allow the calibration to proceed more efficiently. By storing the calibration codes in a non-volatile memory, a search space for calibration codes can be reduced. Thus, a calibration can occur more quickly, and the calibration itself can be improved.

公开(公告)号：US20170179968A1

公开(公告)日：2017-06-22

申请号：US15360816

申请日：2016-11-23

Applicant: Analog Devices Global

Inventor： Hajime SHIBATA

IPC: H03M1/06 ,  H03M3/00 ,  H03K17/082 ,  H02H9/04 ,  H03M1/12

CPC classification number: H03M1/06 ,  H02H9/04 ,  H03K17/0822 ,  H03M1/129 ,  H03M3/322 ,  H03M3/414 ,  H03M3/458

Abstract: Continuous-time analog-to-digital converters (ADCs) such as continuous-time delta-sigma ADCs and continuous-time pipeline ADCs, has input resistor structure at the input. The input resistor structure is typically tunable, and the tunability is usually provided by metal-oxide semiconductor field effect transistor (MOSFET) switches. Core MOSFETs, which has a terminal-to-terminal voltage