A 3.77 nW, 11.4 fJ/b/mm link for reliable wireline communication in ultra-low power on-body sensor networks

Self-powered systems prove useful in health monitoring and fitness tracking, especially in the wearable space. Existing many-node on-body systems monitor health and use power hungry wireless radios. We introduce a reliable wireline transceiver in 130 nm CMOS to address the communication power problem. The transmitter uses complementary source followers for a reduced swing without static current. The receiver uses a subthreshold continuous time comparator with a configurable bias generator for a large voltage operating range and minimal sleep power. A contention free SR latch efficiently stores received data. The transceiver is demonstrated with a 3m (pessimistic) Ethernet cable and a flexible textile-based interconnect. Through Ethernet, the transceiver achieves 1e-9 BER, consuming 5.42 nW with efficiency of 1.20 fJ/b/mm and 585 pW sleep power. Through the textile, it achieves 1e-6 BER, consuming 3.77 nW and 11.4 fJ/b/mm and enables on-body self-powered integrated systems.