A low EMI SIDO wireless power transfer system with 10μsec response time

This paper describes a system of single-inductor-dual-output (SIDO) wireless power delivery for mobile applications. By updating control signal in the feedback loop by every switching clock cycle, fast tracking to the load change is realized while spurious emission is suppressed by using pseudorandom-sequence PWM (PRS-PWM). Transmitter and receiver chips were fabricated in 0.18μm CMOS process and mounted on the wireless power transfer test board. The system achieved response time shorter than 10μsec. Two output voltages are regulated at 8V and 16V, and maximum efficiency of 41% was achieved when the total output power is 500mW.