A compact and power efficient UV dosimeter design

This paper presents a compact and power efficient ultra-violet (UV) dosimeter design. The compact design is achieved by incorporating the principal dosimeter functions onto a CMOS integrated chip. Besides, the external components are arranged in order to minimize the global board BoM (Bill of Materials). On the power consumption side, the CMOS integration aims to reduce the maximum power consumption levels. In addition, a regular sleep/wake-up technique is employed to further decrease the global average power consumption. The high-power blocks are driven by a variable duty-cycle integrated oscillator and turned ON only during short time slots. The device is powered by a primary solar rechargeable battery and a secondary standard emergency battery. The emergency battery is only used when the rechargeable battery gets unable to supply the circuit. The proposed solution aims to prevent any battery replacement during the life-time of the product. An external tri-color LED indicates the skin exposure risk level to UV rays.