Showing papers by "Juan Antonio Gómez Galán published in 2013"
TL;DR: A Gm-C third-order Chebyshev low-pass filter with a novel switched capacitor frequency tuning technique for a zero-IF Bluetooth receiver and a highly linear pseudo-differential transconductor with compact feedback loop able to operate with low supply voltage has been designed.
Abstract: A Gm-C third-order Chebyshev low-pass filter with a novel switched capacitor frequency tuning technique for a zero-IF Bluetooth receiver has been designed. The frequency tuning scheme is simpler and has more relaxed specifications than conventional ones. Furthermore, a highly linear pseudo-differential transconductor with a compact feedback loop able to operate with low supply voltage has been used. This control loop holds the input transistors in triode region and provides high output resistance, keeping high linearity in a wide range of transconductance. The filter bandwidth is 0.5 MHz and the overall scheme consumes 1.1 mA from a 1.8-V supply. The measured third-order intermodulation (IM3) distortion of the filter for a 1 Vpp two-tone signal centered at 300 kHz is -65 dB.
15 citations
TL;DR: In this paper, a novel automatic frequency tuning circuit for continuous-time filters is presented, based on the switched-capacitor technique, which offers an advantage in terms of simplicity resulting from the use of only two matched current sources, an operational amplifier with relaxed specifications and a transconductor that is a replica of the filter transconductors.
Abstract: A novel automatic frequency tuning circuit for continuous-time filters is presented. Based on the switched-capacitor technique, the circuit offers an advantage in terms of simplicity resulting from the use of only two matched current sources, an operational amplifier with relaxed specifications and a transconductor that is a replica of the filter transconductors. Despite the simplicity of the scheme, the accuracy of the system is less than 1 % of frequency error. The circuit has been designed in a 0.5 μm CMOS technology with a 3.3 V power supply and simulation results confirm the suitability of the proposed approach.
2 citations
14 Nov 2013
TL;DR: The design and implementation of a frequency meter that operates in real-time is presented and has been implemented in a low cost FPGA device, concretely, in a SPARTAN-3AN700.
Abstract: The design and implementation of a frequency meter that operates in real-time is presented. It has been implemented in a low cost FPGA device, concretely, in a SPARTAN-3AN700. The measuring device is configurable in resolution time and in maximum measurable period. The main characteristics of the frequency meter are a minimum resolution time of 2.60 ns and a minimum measurable period of four times the resolution time.