102 research outputs found
A very compact KHN filter with multidecade tuning
A very compact implementation of a multifunction
Kerwin Huelsman Newcomb (KHN) filter that can be frequency
tuned almost seven decades, from 0.2 Hz to 1 Mhz, is presented.
Tuning is achieved by means of high-value, programmable
active resistors biased using the quasi floating gate (QFG)
technique and linearisated through capacitive gate voltage
averaging. The circuit, realized in a 0.5 μm standard CMOS
technology using only four CMOS inverters, six small
capacitors, six small resistors and two programmable active
resistors, occupies a total area of 0.02 mm2, dissipates 3.45 mW
and presents a dynamic range at 0.1 % THD of 55.86
Accurate dynamic-feedback CMOS cross-quad suitable for low-voltage operation
This paper presents the implementation of a crossquad
circuit suitable for low-voltage operation. The proposed cell
exploits a dynamic positive feedback gm boosting technique to
achieve linear voltage-to-current conversion, while it manages to
work with low-voltage with no extra bias current and minimal
additional hardware. Results for a 0.5 m CMOS
implementation supplied at 3 V show a 0.972 % voltage-tocurrent
accuracy, improving the 0.867 % accuracy of a
previously reported cross-quad topology also suitable for lowvoltage
operation which is based on folded transistors.Ministerio de Ciencia e Innovación (PET2007-00336,
PET2008-0021)Agencia Española de Cooperación Internacional para el desarrollo - Programa de Cooperación Interuniversitaria e Investigación Científica (AECI-PCI) (A/018704/08)Universidad de Zaragoza (UZ2008-TEC-08
CMOS operational amplifiers with continuous-time capacitive common mode feedback
A simple and power efficient approach for the
implementation of continuous-time common mode feedback
networks using a capacitive averaging network is introduced. It
is shown that low voltage, continuous-time, fully differential rail
to rail operation can be achieved using the proposed technique.
This at the expense of very small additional hardware and no
additional power dissipation One stage, two stage, telescopic and
folded cascode op-amps are discussed as application examples
New high performance second generation CMOS current conveyor
A new high performance second-generation CMOS
current conveyor architecture is presented. It is built using a
differential flipped voltage follower as its input buffer stage and
a cascode current mirror as output stage. It is characterized by
very low output impedance. It provides gain independent high
bandwidth when used to implement a programmable gain
voltage amplifier. Simulation and experimental results in AMI
0.5µm CMOS technology are provided to validate the
characteristics of the design
Super class AB RFC OTA with adaptive local common-mode feedback
A super class AB recycling folded cascode operational transconductance amplifier is presented. It employs local common-mode feedback using two matched tuneable active resistors, allowing to adapt the amplifier to different process variations and loads. Measurement results from a test chip prototype fabricated in a 0.5 μm CMOS process validate the proposal
Low frequency, current mode programmable KHN filters using large-valued active resistors
The present work proposes a new current-mode,
programmable Kerwin Huelsman Newcomb (KHN) filter
suitable for very low frequency processing. The proposed
implementation, developed with only six current mirrors and
two large-valued, programmable active resistors, solves some
of the more challenging problems of low frequency filtering.
HSPICE simulation results using BSIM3.3 models for a 0.5-µm
CMOS technology, are shown. Center frequencies in the range
of 12.4 Hz - 33 Hz, total harmonic distortion less than 1 %, and
static power consumption of 1.05 mW, were observed
0.13-µm CMOS tunable transconductor based on the body-driven gain boosting technique with application in Gm-C filters
We present a low-voltage low-power CMOS tunable
transconductor exploiting body gain boosting to increase the
small-signal output resistance. As a distinctive feature, the proposed
scheme allows the OTA transconductance to be tuned via
the current biasing the gain-boosting circuit. The proposed transconductor
has been designed in a 0.13-µm CMOS technology
and powered from a 1.2-V supply. To show a possible application,
a 0.5-MHz tunable third order Chebyshev low pass filter suitable
for the Ultra Low Power Bluetooth Standard has been designed.
The filter simulations show that all the requirements of the chosen
standard are met, with good performance in terms of linearity,
noise and power consumption
Rail-to-rail class AB CMOS tunable transconductor with -52dB IM3 at 1MHz
A novel CMOS tunable transconductor is presented.
The circuit operates in classAB hence featuring power efficiency.
The internal feedback employed and the use of a linearized triode
transistor for voltage-to-current conversion allows achieving high
linearity. Rail-to-rail input range is obtained by using floatinggate
transistors. Measurement results for a test chip prototype in
a 0.5µm standard CMOS process show an IM3 of -52.13dB at
1MHz for a 2Vpp input and a power consumption of 2.2mW
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