公开(公告)号：US09768793B2

公开(公告)日：2017-09-19

申请号：US15365867

申请日：2016-11-30

Applicant: ANALOG DEVICES GLOBAL

Inventor： Qingdong Meng ,  Hajime Shibata ,  Richard E. Schreier ,  Martin Steven McCormick ,  Yunzhi Dong ,  Jose Barreiro Silva ,  Jialin Zhao ,  Donald W. Paterson ,  Wenhua W. Yang

IPC: H03M3/00 ,  H03M1/08 ,  H03M1/12

CPC classification number: H03M1/08 ,  H03M1/124 ,  H03M3/344 ,  H03M3/414

Abstract: For continuous-time multi-stage noise shaping analog-to-digital converters (CT MASH ADCs), quantization noise cancellation often requires accurate estimation of transfer functions, e.g., a noise transfer function of the front end modulator and a signal transfer function of the back end modulator. To provide quantization noise cancellation, digital quantization noise cancellation filters adaptively tracks transfer function variations due to integrator gain errors, flash-to-DAC timing errors, as well as the inter-stage gain and timing errors. Tracking the transfer functions is performed through the direct cross-correlation between the injected maximum length linear feedback shift registers (LFSR) sequence and modulator outputs and then corrects these non-ideal effects by accurately modeling the transfer functions with programmable finite impulse response (PFIR) filters.

公开(公告)号：US20170179969A1

公开(公告)日：2017-06-22

申请号：US15365867

申请日：2016-11-30

Applicant: ANALOG DEVICES GLOBAL

Inventor： Qingdong Meng ,  Hajime Shibata ,  Richard E. Schreier ,  Martin Steven McCormick ,  Yunzhi Dong ,  Jose Barreiro Silva ,  Jialin Zhao ,  Donald W. Paterson ,  Wenhua W. Yang

IPC: H03M1/08 ,  H03M1/12

CPC classification number: H03M1/08 ,  H03M1/124 ,  H03M3/344 ,  H03M3/414

Abstract: For continuous-time multi-stage noise shaping analog-to-digital converters (CT MASH ADCs), quantization noise cancellation often requires accurate estimation of transfer functions, e.g., a noise transfer function of the front end modulator and a signal transfer function of the back end modulator. To provide quantization noise cancellation, digital quantization noise cancellation filters adaptively tracks transfer function variations due to integrator gain errors, flash-to-DAC timing errors, as well as the inter-stage gain and timing errors. Tracking the transfer functions is performed through the direct cross-correlation between the injected maximum length linear feedback shift registers (LFSR) sequence and modulator outputs and then corrects these non-ideal effects by accurately modeling the transfer functions with programmable finite impulse response (PFIR) filters.

公开(公告)号：US20190154812A1

公开(公告)日：2019-05-23

申请号：US15819976

申请日：2017-11-21

Applicant: Analog Devices Global Unlimited Company

Inventor： Libo Meng ,  Qingdong Meng ,  Wei Wang

IPC: G01S7/486 ,  G01S17/10

Abstract: A lidar system can be used to measure a distance to one or more objects in a target region, such as by transmitting light towards the target and then receiving light reflected or scattered from the target. Received light can be stored as charge on storage elements such as capacitors, where received light can be stored on different storage elements depending on a time of arrival of the received light. A reduction in the number of storage elements can be achieved by providing one or more groups of storage elements, where each group of storage elements can correspond to a digit of a time of flight, where the time of flight can be round trip travel time of a light beam travelling from the lidar system to the target region and then back to the lidar system. Each group of storage elements can be arranged in a binary tree of a decimal tree configuration. Additionally, a time of activation of each of the storage elements can be increased with an increasing time of flight, such as to compensate for a decreased strength of the received light as the time of flight increases.