Limits to the dynamic range of low-power continuous-time integrators

Author(s):  
J.P. Moreira ◽  
M.M. Silva
2005 ◽  
Vol 15 (02) ◽  
pp. 459-476
Author(s):  
C. PATRICK YUE ◽  
JAEJIN PARK ◽  
RUIFENG SUN ◽  
L. RICK CARLEY ◽  
FRANK O'MAHONY

This paper presents the low-power circuit techniques suitable for high-speed digital parallel interfaces each operating at over 10 Gbps. One potential application for such high-performance I/Os is the interface between the channel IC and the magnetic read head in future compact hard disk systems. First, a crosstalk cancellation technique using a novel data encoding scheme is introduced to suppress electromagnetic interference (EMI) generated by the adjacent parallel I/Os . This technique is implemented utilizing a novel 8-4-PAM signaling with a data look-ahead algorithm. The key circuit components in the high-speed interface transceiver including the receive sampler, the phase interpolator, and the transmitter output driver are described in detail. Designed in a 0.13-μm digital CMOS process, the transceiver consumes 310 mW per 10-Gps channel from a I-V supply based on simulation results. Next, a 20-Gbps continuous-time adaptive passive equalizer utilizing on-chip lumped RLC components is described. Passive equalizers offer the advantages of higher bandwidth and lower power consumption compared with conventional designs using active filter. A low-power, continuous-time servo loop is designed to automatically adjust the equalizer frequency response for the optimal gain compensation. The equalizer not only adapts to different channel characteristics, but also accommodates temperature and process variations. Implemented in a 0.25-μm, 1P6M BiCMOS process, the equalizer can compensate up to 20 dB of loss at 10 GHz while only consumes 32 mW from a 2.5-V supply.


2017 ◽  
Vol 27 (03) ◽  
pp. 1850044 ◽  
Author(s):  
Alireza Shamsi ◽  
Esmaeil Najafi Aghdam

Power consumption and bandwidth are two of the most important parameters in design of low power wideband modulators as power consumption is growing with the increase in bandwidth. In this study, a multi bit wideband low-power continuous time feed forward quadrature delta sigma modulator (CT-FF-QDSM) is designed for WLAN receiver applications by eliminating adders from modulator structure. In this method, a real modulator is designed and its excess loop delay (ELD) is compensated, then, it is converted into a quadrature structure by applying the complex coefficient to loop filter. Complex coefficients are extracted by the aid of a genetic algorithm to further improve signal to noise ratio (SNR) for bandwidth. One of the disadvantages of CT-FF-QDSM is the adders of loop filters which are power hungry and reduce the effective loop gain. Therefore, the adders have been eliminated while the transfer function is intact in the final modulator. The system level SNR of the proposed modulator is 62.53[Formula: see text]dB using OSR of 12. The circuit is implemented in CMOSTSMC180nm technology. The circuit levels SNR and power consumption are 54[Formula: see text]dB and 13.5[Formula: see text]mW, respectively. Figure of Merit (FOM) obtained from the proposed modulator is about 0.824 (pj/conv) which is improved (by more than 40%) compared to the previous designs.


2018 ◽  
Vol 27 (07) ◽  
pp. 1850104 ◽  
Author(s):  
Yuwadee Sundarasaradula ◽  
Apinunt Thanachayanont

This paper presents the design and realization of a low-noise, low-power, wide dynamic range CMOS logarithmic amplifier for biomedical applications. The proposed amplifier is based on the true piecewise linear function by using progressive-compression parallel-summation architecture. A DC offset cancellation feedback loop is used to prevent output saturation and deteriorated input sensitivity from inherent DC offset voltages. The proposed logarithmic amplifier was designed and fabricated in a standard 0.18[Formula: see text][Formula: see text]m CMOS technology. The prototype chip includes six limiting amplifier stages and an on-chip bias generator, occupying a die area of 0.027[Formula: see text]mm2. The overall circuit consumes 9.75[Formula: see text][Formula: see text]W from a single 1.5[Formula: see text]V power supply voltage. Measured results showed that the prototype logarithmic amplifier exhibited an 80[Formula: see text]dB input dynamic range (from 10[Formula: see text][Formula: see text]V to 100[Formula: see text]mV), a bandwidth of 4[Formula: see text]Hz–10[Formula: see text]kHz, and a total input-referred noise of 5.52[Formula: see text][Formula: see text]V.


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