Low-voltage silicon （Si）-based light-emitting diode （LED） is designed based on the former research of LED in Si-based standard complementary metal oxide semiconductor （CMOS） technology. The low-voltage LED is designed under the research of cross-finger structure LEDs and sophisticated structure enhanced LEDs for high efficiency and stable light source of monolithic chip integration. The device size of low-voltage LED is 45.85x38.4 （#m）, threshold voltage is 2.2 V in common condition, and temperature is 27 ~C. The external quantum efficiency is about 10-6 at stable operating state of 5 V and 177 mA.
This paper presents a third-order single-loop delta-sigma modulator of a biomedical micro-system for portable electroencephalogram（EEG） monitoring applications.To reduce the power consumption,the loop filter of the proposed modulator is implemented by applying a switched-capacitor structure.The modulator is designed in a 0.35-μm 2P4M standard CMOS process,with an active area of 365×290μm^2.Experimental results show that this modulator achieves a 68 dB dynamic range with an input sinusoidal signal of 100 Hz signal bandwidth under a 64 over-sampling ratio.The whole circuit consumes 515μW under a 2.5 V power supply,which is suitable for portable EEG monitoring.
