Title :
A 2.0Vpp input, 0.5V supply Delta Amplifier with A-to-D conversion
Author :
Masui, Yoshihiro ; Yoshida, Takeshi ; Iwata, Atsushi
Author_Institution :
Grad. Sch. of Adv. Sci. of Matter, Hiroshima Univ., Higashi-Hiroshima
Abstract :
Recent progress in scaled CMOS technologies can enhance a signal bandwidth and clock frequency of analog-digital mixed VLSIs. However, inevitable supply voltage reduction causes signal voltage mismatch between a non-scaled analog chip and a scaled A-D mixed chip. To solve the problem, we present a Delta-Amplifier (DeltAMP) which can handle larger signal amplitude than the supply voltage. DeltaAMP operates by folding an analog signal within a voltage window using a virtual ground amplifier, modulation switches and comparators. The folded delta signal has to be reconstructed to the ordinal signal. A reconstruction circuit is also proposed based on Analog-Time-Digital conversion (ATD) in which-pulse width analog information obtained at the comparators in DeltAMP, is converted to a digital signal by counting. A test chip of DeltAMP with ATD using a 90 nm CMOS technology, achieved input voltage range of 2.0 Vpp at a 0.5 V supply, and SNR of 62 dB at signal bandwidth of 120 kHz. Measured power consumption was as low as 150 muW at 0.5 V supply.
Keywords :
CMOS integrated circuits; VLSI; amplifiers; analogue-digital conversion; comparators (circuits); mixed analogue-digital integrated circuits; modulation; ATD; CMOS technology; analog-digital mixed VLSIs; analog-time-digital conversion; bandwidth 120 kHz; comparators; delta amplifier; digital signal counting; folded delta signal; modulation switches; signal reconstruction; size 90 nm; virtual ground amplifier; voltage 0.5 V; voltage window; Analog-digital conversion; Bandwidth; CMOS technology; Circuits; Clocks; Delta modulation; Frequency; Switches; Very large scale integration; Voltage;
Conference_Titel :
Solid-State Circuits Conference, 2008. A-SSCC '08. IEEE Asian
Conference_Location :
Fukuoka
Print_ISBN :
978-1-4244-2604-1
Electronic_ISBN :
978-1-4244-2605-8
DOI :
10.1109/ASSCC.2008.4708779