Title :
A low power continuous time band pass sigma delta modulator using linearity enhanced OTA
Author :
Sohel, Mohammed Arifuddin ; Keshava Reddy, K. Chenna ; Naaz, Maliha ; Naseeb, M.A.
Author_Institution :
ECED, Muffakham Jah Coll. of Eng. & Technol., Hyderabad, India
Abstract :
This paper presents a low power continuous-time bandpass sigma delta modulator for analog to digital converter (ADC) over 5 MHz band. The modulator consists of a fourth order design operating at a Sampling Frequency of 280MHz. The operational transconductance amplifier (OTA) is linearized by using source degeneration technique. This paper investigates the effect of OTA linearization on the modulator performance. It is observed that Signal to Quantization Noise Ratio (SQNR) with a non-linear OTA is of 46.6dB and it is 55.07dB with a Source degenerated OTA showing a marked increase of 1.5 bits(9 dB) in resolution of modulator. Further, optimum transistor sizing leads to a very low power consumption of 10.9mW and a figure of merit of 2.445pJ/bit.
Keywords :
linearisation techniques; low-power electronics; operational amplifiers; sigma-delta modulation; OTA; SQNR; frequency 280 MHz; frequency 5 MHz; linearization; low power continuous time band pass sigma delta modulator; operational transconductance amplifiers; power 10.9 mW; signal to quantization noise ratio; source degeneration; Band-pass filters; Frequency modulation; Linearity; Receivers; Sigma-delta modulation; Transconductance; Band Pass; Continuous Time; Linearity; Low Power; Sigma Delta Modulator; Source degeneration;
Conference_Titel :
Microelectronics and Electronics (PrimeAsia), 2013 IEEE Asia Pacific Conference on Postgraduate Research in
Conference_Location :
Visakhapatnam
Print_ISBN :
978-1-4799-2750-0
DOI :
10.1109/PrimeAsia.2013.6731168
