Design of the analog components for a high sampling rate continuous time ΣΔ modulator in 0.4 μm HEMT technology

Author

Olmos, Alfredo ; Miyashita, Takumi ; Nihei, Mizuhisa ; Charry, Edgar ; Watanabe, Yuu

Author_Institution

Escola Politecnica, Sao Paulo Univ., Brazil

fYear

1998

fDate

2-4 Mar 1998

Firstpage

138

Lastpage

141

Abstract

The design of the key components for a high sampling rate ΣΔ modulator implemented on a 0.4 μm InGaP-InGaAs HEMT technology is described. The circuit, a 2nd-order continuous-time ΣΔ modulator, has a fully differential architecture including pairs of highly linear V-I converters, high-speed opamps, high-speed 1-bit DAC units, and a new polarity alternating feedback (PAF) comparator. Working at a sampling rate of 4.9 GHz and a signal bandwidth of 100 MHz, the fabricated modulator exhibits 43 dB signal-to-noise ratio (SNR), equivalent to 7.2 bits resolution. The circuit occupies an active area of 0.9 mm², and dissipates 400 mW from a 3.2 V power supply. Such performance corresponds to the highest sampling rate and lowest power consumption for an oversampled A/D converter in III-V technology known to us

Keywords

HEMT integrated circuits; III-V semiconductors; circuit feedback; continuous time systems; gallium arsenide; gallium compounds; indium compounds; sigma-delta modulation; signal sampling; 0.4 micron; 100 MHz; 2nd-order ΣΔ modulator; 3.2 V; 4.9 GHz; 400 mW; 43 dB; HEMT technology; InGaP-InGaAs; analog components design; continuous time ΣΔ modulator; fully differential architecture; high sampling rate; high-speed DAC units; high-speed opamps; highly linear V-I converters; oversampled A/D converter; polarity alternating feedback comparator; Analog-digital conversion; Bandwidth; Circuit noise; Digital modulation; HEMTs; Power semiconductor switches; Power supplies; Sampling methods; Signal resolution; Signal to noise ratio;

fLanguage

English

Publisher

ieee

Conference_Titel

Devices, Circuits and Systems, 1998. Proceedings of the 1998 Second IEEE International Caracas Conference on

Conference_Location

Isla de Margarita

Print_ISBN

0-7803-4434-0

Type

conf

DOI

10.1109/ICCDCS.1998.705821

Filename

705821