## Combining Multipath and Single-Path Time-Interleaved Delta-Sigma Modulators

### BibTeX

@MISC{Gharbiya_combiningmultipath,

author = {Ahmed Gharbiya and David A. Johns},

title = {Combining Multipath and Single-Path Time-Interleaved Delta-Sigma Modulators},

year = {}

}

### OpenURL

### Abstract

Abstract—In this brief, single-path time-interleaved delta-sigma modulators are analyzed and evaluated. It is found that finite opamp gain and bandwidth result in a mismatch between the noise transfer functions of the internal quantizers which degrades the performance of the architecture. A hybrid topology where the first stage uses multiple integrators while the rest of the modulator uses a single path of integrators is proposed to mitigate the mismatch problem. Index Terms—Analog-to-digital converter (ADC), delta-sigma, oversampling, time-interleaved.

### Citations

82 |
Understanding Delta-Sigma Data Converters
- Schreier, Temes
- 2005
(Show Context)
Citation Context ... MPTI and single-loop topologies. For this purpose, the second-order SPTI modulator shown in Fig. 2 [6] is compared to a traditional second-order cascade of integrators with feedback (CIFB) modulator =-=[11]-=- and the MPTI modulator shown in Fig. 3 [1] with a -factor of 1. The time-interleaved-by-2 modulators are clocked at half of the rate of the CIFB modulator. In other words, the OSR of the CIFB and the... |

80 |
Temes, Analog MOS integrated circuits for signal processing
- Gregorian, C
- 1986
(Show Context)
Citation Context ...icient and and are the sampling and the integrating capacitors respectively. Finite opamp gain (A) introduces a gain error and a phase error which modifies the integrator transfer function as follows =-=[10]-=-: where , , and is the integrator feedback factor. Next, finite opamp unity-gain frequency introduces a gain error in the integrator output in response to a step input: , where is the available settli... |

15 | Time-interleaved oversampling A/D converters: theory and practice
- Khorini-Poorfard, Lim, et al.
- 1997
(Show Context)
Citation Context ...d parallelism is not a straightforward process for converters due to their recursive nature. To overcome this problem, the block filtering concept can be used to implement time-interleaved modulators =-=[1]-=-. The internal circuitry of the block filter operates in parallel and at a reduced rate by the interleaving factor . For example, using this transformation for a modulator with allows the internal mod... |

7 | Novel Topologies for time interleaved deltasigma modulators - Kozak, Kale - 2000 |

3 |
Time-interleaved multirate sigma delta modulators
- Colodro, Torralba, et al.
- 2005
(Show Context)
Citation Context ...ese integrator increases significantly as shown later in this brief. Another interesting topology uses time-interleaving within a multirate system to clock all of the integrators at the same low rate =-=[8]-=-. There are two main contributions of this paper. The first contribution is an analysis of SPTI modulators where we see that their sensitivities to opamp bandwidth and dc gain are significantly worse ... |

2 |
Domino free 4-path time-interleaved second order sigma-delta modulator
- Lee, Choi, et al.
- 2004
(Show Context)
Citation Context ...are referred to as the multipath time-interleaved (MPTI) modulators. Modified time-interleaved architectures that require a single modulator with extra quantizers and interconnects have been reported =-=[3]-=-–[7]. Since these topologies require a single modulator regardless of the interleaving order, they are referred to as the single-path time-interleaved (SPTI) modulators [4]. Two SPTI modulators have b... |

2 |
Time-interleaved sigma-delta modulator using output prediction scheme
- Lee, Maloberti
- 2004
(Show Context)
Citation Context ...connects have been reported [3]–[7]. Since these topologies require a single modulator regardless of the interleaving order, they are referred to as the single-path time-interleaved (SPTI) modulators =-=[4]-=-. Two SPTI modulators have been realized in 0.18- m CMOS technology: [5] presented a continuous-time implantation and [7] presented a Manuscript received February 18, 2008; revised June 01, 2008. Curr... |

1 | A time-interleaved continuous-time 16 modulator with 20-MHz signal bandwidth - Caldwell, Johns - 2006 |

1 |
High-speed oversampling analog-to-digital converters
- Gharbiya, Caldwell, et al.
- 2005
(Show Context)
Citation Context ...me-interleaved structures where each branch processes alternating samples [1]. The modified sampling has no effect on the NTFs of the modulator, however, the signal transfer function (STF) is changed =-=[6]-=-. The modified STF has a negligible effect on the 1549-7747/$25.00 © 2008 IEEE Authorized licensed use limited to: The University of Toronto. Downloaded on February 20, 2009 at 11:13 from IEEE Xplore.... |

1 |
A power-efficient two-channel time-interleaved 61 modulator for broadband applications
- Lee, Kwon, et al.
- 2007
(Show Context)
Citation Context ...referred to as the multipath time-interleaved (MPTI) modulators. Modified time-interleaved architectures that require a single modulator with extra quantizers and interconnects have been reported [3]–=-=[7]-=-. Since these topologies require a single modulator regardless of the interleaving order, they are referred to as the single-path time-interleaved (SPTI) modulators [4]. Two SPTI modulators have been ... |

1 |
Architecture alternatives for time-interleaved and inputfeedforward delta-sigma modulators
- Gharbiya
- 2008
(Show Context)
Citation Context ...erleaving factor of 2 used in the evaluation of SPTI architecture. Utilizing the zero-insertion concept [2], additional SPTI discrete-time modulators can be developed using the method presented above =-=[9]-=-. III. EVALUATION OF THE SPTI MODULATOR Several simulations using Matlab and Simulink are used to evaluate the performance of the SPTI modulator and compare it to traditional structures. The focus of ... |