An ultra-low power integer-N frequency synthesizer for MICS transceivers

The ultra-low power frequency synthesizer for the transceivers used in the application of Medical Implantable Communication Services (MICS) is presented. The MICS band is from 402 to 405 MHz. Each channel spacing is 300 kHz. Integer-N architecture is used to implement the frequency synthesizer. The post layout simulations show that the total power consumption of the system is less than 260μW at 1.2 V power supply. The gains of the charge pump and voltage controlled oscillator (VCO) are 0.18μA/rad and 50 MHz/V, respectively. The standard 300 kHz external clock is used as the reference. The design is carried out in the IBM 90 nm 9LPRF CMOS technology.