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The dual-rank configuration is one of the parallelization methods to increase the memory capacity for mobile applications. However, the stub mainly composed of the redistribution layer causes resonance reflections and its reflection interval reaches the bit period, which distorts signal and limits the signal bandwidth. A single-ended duobinary transmitter that utilizes the reflection is presented for dual-rank mobile memory interfaces where reflections dominate. The reflection is included in the transfer function for duobinary modulation, which allows the transmitter to have a wide eye opening and high energy efficiency. Two-tap reverse feed-forward equalization and slew-rate control are used to support the duobinary modulation in combination with the reflection. A prototype chip fabricated in a 65 nm CMOS process has an area of 0.0378 mm2 and consumes 1.24 pJ/bit. It is verified at data rates of 8, 9 and 10 Gb/s/pin where the flight time of the 9 mm stub is 55.6 ps. [ABSTRACT FROM AUTHOR]

We combine 2-tap feed-forward amplitude equalization with phase equalization by 4-tap integrated pulse-width modulation. In a $\text{V}_{\mathbf {SS}}$ -terminated transmitter, amplitude equalization is selected for pull-up data transmission, and phase equalization for pull-down data transmission, and the strength of equalization can be controlled depending on channel losses. This combines the strength of amplitude equalization with the energy efficiency of phase equalization. A prototype quarter-rate transmitter for memory interfaces, fabricated in a 65nm CMOS process, performed single-ended signaling at a data-rate of 16Gb/s/pin over a channel with a loss of 14.7dB. Its energy efficiency is 1.04pJ/bit/pin and the figure-of-merit is 0.070pJ/bit/pin/dB. [ABSTRACT FROM AUTHOR]