Effective number of bits

About: Effective number of bits is a research topic. Over the lifetime, 3776 publications have been published within this topic receiving 46130 citations.

A cost-efficient high-speed 12-bit pipeline ADC in 0.18-μm digital CMOS

Abstract: A 12-bit pipeline ADC fabricated in a 0.18-μm pure digital CMOS technology is presented. Its nominal conversion rate is 110 MS/s and the nominal supply voltage is 1.8 V. The effective number of bits is 10.4 when a 10-MHz input signal with 2Vp―p signal swing is applied. The occupied silicon area is 0.86 mm 2 and the power consumption equals 97 mW. A switched capacitor bias current generator scales the opamp bias currents automatically with the conversion rate, which gives scaleable power consumption and full performance of the ADC from 20 to 140 MS/s.

A 7b 1.1GS/s Reconfigurable Time-Interleaved ADC in 90nm CMOS

Abstract: A time-interleaved pipeline ADC is designed with the reconfigurable resolution and sampling rate, Fs, to accommodate different operation scenarios. The main offset and gain mismatches between four sub-ADCs are modulated to the frequency of F/2 by the reference-and opamp-sharing techniques. Fabricated in 90 nm CMOS, the 7 bit ADC has an ENOB of 6.5 at 1.1 GHz sampling rate. The I/Q ADCs totally consume power of 92 mW from a 1.3 V supply.

Photonic analog-to-digital converters A tutorial

Abstract: Each new bit of ADC resolution requires an increase in signal-to-noise-and-distortion ratio (SNDR) of 6 dB • ENOB without noise bandwidth is meaningless • Decreasing the noise bandwidth by a factor of 4 increases ADC resolution by 1 ENOB - e.g. the Tektronix 50 GS/s digital oscilloscope has • 5 ENOB over 16 GHz • 7 ENOB over 1 GHz • Every time you sneeze, you lose a few 1/10's of an ENOB • Optical photons are very energetic compared to RF photons - Shot noise is irrelevant for electronic ADCs - Shot noise is a fundamental limit in photonic ADCs • Photonic ADCs usually contain a microwave photonic link - Standard analysis gives the SNR/CNR - Max ENOB over a given noise bandwidth readily estimated • If commercialized, photonic ADCs will resemble data conversion modules and digital oscilloscopes rather than single chip ADCs

A 90nm CMOS 1.2V 10b power and speed programmable pipelined ADC with 0.5pJ/conversion-step

Abstract: A 10b pipelined ADC with programmable speed and power achieves a power efficiency of 0.5pJ/conversion-step for sampling frequencies between 25 and 100MHz. Measurements show an ENOB of 9.3b, ERBW exceeding 100MHz, and THD<-65dB with a supply voltage of 1.2V. Chip area is 0.3mm2 in a 90nm digital CMOS process

Flexible rate split method for MIMO transmission

Abstract: A method for transmitting a packet of N input bits includes encoding all of the N bits as a single entity, such as with an interleaver of length N within a turbo coder, outputting M encoded bits, channel interleaving the M bits, splitting the M encoded bits into a parallel first and second portion, and transmitting them over separate channels to achieve spatial diversity. The size of the first and second portion is determined based on a closed feedback loop that provides some knowledge of the channel, preferably a measure of channel capacity. The feedback loop may also provide channel knowledge to a subpacket selector associated with each transmit antenna, which determines an appropriate rate for that channel and selects subpackets to fill a transmission packet for that channel. The subpacket selectors choose a subpacket of systematic bits and fill the remaining transmission packet size with subpackets of parity bits. Eigenvectors maybe employed to transmit each transmission packet over more than one channel with a power disparity between the channels. A transmitter according to the present invention is also described.