Dynamic Terminations for Low-Power High-Speed Chip Interconnection in Portable Equipment

Takayuki KAWAHARA  Masakazu AOKI  Katsutaka KIMURA  

IEICE TRANSACTIONS on Electronics   Vol.E78-C    No.4    pp.404-413
Publication Date: 1995/04/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Low-Voltage, Low-Power Integrated Circuits)
Category: Digital Circuits
dynamic termination,  transmission line,  low-power,  high-speed,  

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Two types of dynamic termination, latch-type and RC-type, are useful for low-power high-speed chip interconnection where the transmission line is terminated only if the signal is changed. The gate of the termination MOS in the latch-type is driven by a feedback inverter, and that in the RC-type is driven by a differentiating signal through the resistor and capacitor. The power dissipation is 13% for the latch-type, and 11% for the RC-type in a DC termination scheme, and the overshoot is 32% for the latch-type, and 16% for the RC-type in an open scheme, both at a signal amplitude of 2 V. The RC-type is superior for signal swing as low as a 1 V. On the other hand, RC termination requires large capacitance, and thus high power. Diode termination is not effective for a small swing because of the large ON voltage of diodes.