公开(公告)号：US10181860B1

公开(公告)日：2019-01-15

申请号：US15794367

申请日：2017-10-26

Applicant: Analog Devices Global Unlimited Company

Inventor： Sharvil Pradeep Patil ,  Hajime Shibata ,  Wenhua William Yang ,  David Nelson Alldred ,  Yunzhi Dong ,  Gabriele Manganaro ,  Kimo Tam

IPC: H03M1/14 ,  H03M1/06 ,  H03M1/00 ,  H03M3/00

Abstract: A residue generation apparatus for use in continuous-time and hybrid ADCs is proposed. The apparatus includes a quantizer for digitizing an analog input to generate a digital output, and means for applying a first transfer function to the digital output from the quantizer to generate a digital input to a feedforward DAC, based on which the DAC can generate a feedforward path analog output. The apparatus further includes means for applying a second, continuous-time, transfer function to the analog input provided to the quantizer to generate a forward path analog output, and a subtractor for generating a residue signal based on a difference between the forward path analog output and the feedforward path analog output. Proposed apparatus allows selecting a combination of the first and second transfer functions so that, when each is applied in its respective path, the residue signal passed to further stages of an ADC is reduced.

公开(公告)号：US09124292B2

公开(公告)日：2015-09-01

申请号：US14537532

申请日：2014-11-10

Applicant: ANALOG DEVICES GLOBAL

Inventor： Zhao Li ,  Shipra Bhal ,  Kevin Glenn Gard ,  David Nelson Alldred ,  Christopher Mayer ,  Trevor Clifford Caldwell ,  David J. McLaurin ,  Victor Kozlov

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

CPC classification number: H03M3/384 ,  H03M1/00 ,  H03M1/1009 ,  H03M1/12 ,  H03M3/458

Abstract: A calibration system for an analog-to-digital converter (ADC) an internal ADC that receives an analog input and converts the analog input to digital multi-bit data. The calibration system also includes a reference shuffling circuit that shuffles reference values of comparators of the internal ADC. Further, the calibration system includes a calibration circuit that calibrates the comparators of the internal ADC. The calibration system includes a digital block that measures an amplitude based on the digital multi-bit data. Additionally, the calibration system includes calibration logic that controls the calibration circuit based on an output of the digital block.

Abstract translation: 用于模数转换器（ADC）的校准系统，内部ADC接收模拟输入并将模拟输入转换为数字多位数据。 该校准系统还包括一个参考混洗电路，它洗牌内部ADC的比较器参考值。 此外，校准系统包括校准电路，校准内部ADC的比较器。 校准系统包括基于数字多位数据测量幅度的数字块。 此外，校准系统包括基于数字块的输出来控制校准电路的校准逻辑。

公开(公告)号：US09843337B1

公开(公告)日：2017-12-12

申请号：US15460433

申请日：2017-03-16

Applicant: Analog Devices Global

Inventor： Zhao Li ,  Trevor Clifford Caldwell ,  David Nelson Alldred ,  Yunzhi Dong ,  Prawal Man Shrestha ,  Jialin Zhao ,  Hajime Shibata ,  Victor Kozlov ,  Richard E. Schreier ,  Wenhua W. Yang

IPC: H03M1/12 ,  H03M1/10 ,  H03M3/00

CPC classification number: H03M1/1023 ,  H03M1/0673 ,  H03M1/1009 ,  H03M1/12 ,  H03M1/361 ,  H03M3/384 ,  H03M3/414

Abstract: Analog-to-digital converters (ADCs) can be used inside ADC architectures, such as delta-sigma ADCs. The error in such internal ADCs can degrade performance. To calibrate the errors in an internal ADC, comparator offsets of the internal ADC can be estimated by computing a mean of each comparator of the internal ADC. Relative differences in the computed means serves as estimates for comparator offsets. If signal paths in the internal ADC are shuffled, the estimation of comparator offsets can be performed in the background without interrupting normal operation. Shuffling of signal paths may introduce systematic measurement errors, which can be measured and reversed to improve the estimation of comparator offsets.

公开(公告)号：US10187075B1

公开(公告)日：2019-01-22

申请号：US15974548

申请日：2018-05-08

Applicant: Analog Devices Global Unlimited Company

Inventor： Sharvil Pradeep Patil ,  Hajime Shibata ,  Yunzhi Dong ,  David Nelson Alldred ,  Frank Murden ,  Lawrence A. Singer

IPC: H03M1/00 ,  H03M1/16 ,  H03M1/06

Abstract: Residue generation systems for use in continuous-time and hybrid ADCs are described. An exemplary system includes a filter, e.g. a FIR filter, for generating a filtered analog output based on an analog input, a quantizer for generating a digital input to a feedforward DAC based on the filtered analog output generated by the filter, a feedforward DAC for generating a feedforward path analog output based on the digital input generated by the quantizer, and a subtractor for generating a residue signal based on the feedforward path analog output. Providing a filter that filters the analog input before it is quantized advantageously allows blockers to be attenuated before they are sampled and aliased by the quantizer. At least some of the residue generation systems described herein may be implemented with relatively small design and power dissipation overheads.

公开(公告)号：US10056914B2

公开(公告)日：2018-08-21

申请号：US15282586

申请日：2016-09-30

Applicant: ANALOG DEVICES GLOBAL

Inventor： Zhao Li ,  Hajime Shibata ,  Trevor Clifford Caldwell ,  Richard E. Schreier ,  Victor Kozlov ,  David Nelson Alldred ,  Prawal Man Shrestha

IPC: H03M1/10 ,  H03M1/36 ,  H03M3/00

CPC classification number: H03M1/1023 ,  H03M1/1004 ,  H03M1/1038 ,  H03M1/1085 ,  H03M1/361 ,  H03M3/378 ,  H03M3/384

Abstract: A flash analog-to-digital converter (ADC) includes comparators that convert an analog input signal to a digital output signal. Offsets of these comparators introduce noise and can hurt the performance of the ADC. Thus, these comparators are calibrated using calibration codes. Conventional calibration methods determine these calibration codes by removing the ADC from an input signal. Otherwise, it is difficult to distinguish the noise from the signal in the calibration measurement. In contrast, an embodiment can determine the calibration codes while the ADC converts the input signal to a digital signal. Such an embodiment can be achieved by a frequency-domain technique. In an embodiment employing a frequency-domain power meter, an input signal can be removed from the power measurement. This removal enables accurate measurement of in-band noise without having the measurement be corrupted by input signal power.

公开(公告)号：US09912342B2

公开(公告)日：2018-03-06

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 ,  H03M1/34 ,  H03M1/12 ,  H03M1/06 ,  H03M3/00

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.