Asynchronous Pulse Transmitter for Power Reduction in Inductive-Coupling Link

An asynchronous pulse transmitter is proposed to achieve low power in inductive-coupling link. The conventional asynchronous transmitter, H-bridge inductive-coupling transmitter, consumes large static (DC) current consumption. Therefore the transmit power dissipation is dominant in the total inductive-coupling power dissipation. The proposed pulse inductive-coupling transmitter eliminates the static (DC) current consumption. It provides linear power scalability which significantly reduces the power consumption especially at low data rate operation for low-power mobile applications. To verify the proposed technique, we designed and fabricated test chips in TSMC 0.18 mu m complementary metal oxide semiconductor (CMOS) technology. Both proposed pulsed transmitter and conventional H-bridge transmitter is implemented in the test chip for comparison. Power reduction to 1/4 at 1.5 Gbps and 1/60 at 100 Mbps is achieved compared to the conventional transmitter. Also a crosstalk immune inductive-coupling receiver is presented for low-power relayed transmission using the proposed pulse transmitter. Crosstalk guard circuit is implemented in the receiver to ignore crosstalk. Data is successfully transferred using relayed transmission with proposed transceiver at up to 400 Mbps. (C) 2012 The Japan Society of Applied Physics