Title :
Integrated Variable Gain Amplifier and Active RC Ladder Filters
Author :
Sindunata, Rendra ; Khannur, Pradeep B.
Author_Institution :
Inst. of Microelectron., Singapore
Abstract :
An integrated variable gain amplifier (VGA) and low pass filter (LPF) used in RFID reader are being presented here. The design consists of a preamp, a LPF followed by a VGA. The LPF is a fully differential ladder filter with option to switch into 2 modes. First mode is for listen before talk (LBT) mode with passband frequency of 331 kHz. Second mode is for Talk mode with passband frequency of 1.53 MHz. The VGA is able to provide programmable gain from 12 dB to 60 dB with 1 dB step and suppress the low frequency components below 4 kHz to cancel the DC offset. Both the control for LPF mode and VGA gain will be provided by baseband circuit. For the use of VGA control a received signal strength indicator (RSSI) circuits is also included. The designs have been implemented in 0.18-mum CMOS technology which consumes 56 mA for Talk mode and 71 mA for LBT mode from 1.8 V supply voltage.
Keywords :
CMOS analogue integrated circuits; RC circuits; active filters; differential amplifiers; gain control; integrated circuit design; ladder filters; low-pass filters; radiofrequency identification; readout electronics; CMOS technology; DC offset cancellation; LPF; RFID reader; VGA gain control; active RC ladder filters; baseband circuit; current 56 mA; current 71 mA; differential ladder filter; frequency 1.53 MHz; frequency 331 kHz; gain 12 dB to 60 dB; integrated variable gain amplifier; listen before talk mode; low pass filter; programmable gain; received signal strength indicator circuits; size 0.18 mum; talk mode; voltage 1.8 V; Active filters; Baseband; CMOS technology; Circuits; Frequency; Gain; Low pass filters; Passband; Radiofrequency identification; Switches;
Conference_Titel :
Integrated Circuits, 2007. ISIC '07. International Symposium on
Conference_Location :
Singapore
Print_ISBN :
978-1-4244-0797-2
Electronic_ISBN :
978-1-4244-0797-2
DOI :
10.1109/ISICIR.2007.4441794
