An integer-N frequency synthesizer for medical implantable devices

This thesis proposes an Integer-N frequency synthesizer in TSMC 0.18µm technology. The design is aimed for MICS (Medical Implantable Communication Services) devices operating at 402-406 MHz. A low phase noise, wide frequency range Quadrature Voltage Controlled Oscillator (QVCO) has been designed and simulated. The simulated phase noise @ 160 KHz offset is -100.3 dBc/Hz with the power consumption of 0.9 mW. This design addresses the small size, low phase noise and low power requirements for the Implantable devices. A wide frequency range Source Coupled Logic (SCL)32/33 prescaler divider has been designed. The program counter and Swallow counter have been implemented in Verilog-A which allow a division ratio of 2690 from the output of the QVCO. A phase frequency detector based on a modified TSPC D-Flip Flop is designed, which leads to a faster response time. The phase frequency detector, the charge pump, and the loop filter would consume 0.5 mW power. The total power consumption of the synthesizer is at 4.6 mW with 2% steady state settlement time of 160 μs.