High-Efficiency Transmission for Medical Implants

In this article, by means of appropriate circuit design the total efficiency can be optimized. On a circuit level, a high efficiency for an inductive power link can be obtained by using a class E amplifier and an active power regulator. The class E amplifier has three advantages: it has a high efficiency, it has a minimal power consumption when the secondary coil of the inductive link is shorted, and it reaches its normal operation almost immediately after turn on (although a high-Q LC circuit is involved). These properties are exploited in the design of two different power regulators, which are simple on-off control systems. The power regulators have never been realized, but the Micro-Cap simulations are really very promising. The author is hopeful that these considerations may inspire young designers to optimize inductive powering systems. Recent papers in reference [6], [7] show that modeling and designing an inductive power link with a high efficiency is still a challenge.