A 5 Gb/s Voltage-Mode Transmitter Using Adaptive Time-Based De-Emphasis
Date Issued
2016
Date
2016
Author(s)
Su, Wun-Jian
Abstract
With the CMOS technology continues to progress, the data rate is also fast growing in different applications. As data rate keeps rising, many significant problems appear. One of the problem is that the channel bandwidth limits compared with the data rate. It will result in a significant inter symbol interference (ISI) and cause signal distortion. In communication systems, equalizers are widely adopted in transmitter side or receiver side to deal with ISI. The length or the material of the transmission channel may be different for various applications. Therefore, an equalizer with the adaptive algorithm is widely adopted in communication systems. A 5-Gb/s adaptive voltage-mode (VM) transmitter using time-based de-emphasis is presented. The duty cycle of the pulse width modulation is adjusted by the spectrum-balancing technique. For different cable lengths, the duty cycle of the PWM data is adaptively adjusted. The proposed adaptive VM transmitter does not require any auxiliary channels. The proposed adaptive VM transmitter can tolerate the process variations. This adaptive transmitter is fabricated in a 40-nm CMOS process. The active areas of the transmitter and the receiver are 0.075mm2 and 0.105mm2, respectively. For a 5-Gb/s PRBS of 27-1 passing through a 9-m coaxial cable with a 15.35-dB loss, the measured root-mean-square jitters of the recovered data is 12.25 ps. The measured bit error rate is less than 10-12. The settling time for adaptive time-based de-emphasis is 2.048us. For a 1.1V supply voltage, the power of the transmitter is 9.3mW and the total power of the transceiver is 17.5mW.
Subjects
Voltage-mode transmitter
pulse-width modulation
inter-symbol interference
adaptive de-emphasis
Type
thesis