A low power low voltage 16 bit audio ΣΔ modulator

A 16bit audio SigmaDelta modulator is designed, with only 360 muw power dissipation under 0.9 V supply. A feedforward third-order single loop architecture is adopted to decrease the power dissipation. A novel double-boost switch is proposed in the design to decrease the on-resistance. A low power class-AB operational transconductance amplifier (OTA) with proposed self-adapted bias circuit is applied in the modulator, which make OTA can tolerate higher common mode input voltage than that with traditional bias circuit. The modulator is designed and fabricated in SMIC 0.18 mum 1P6M CMOS technology, with the core area of 0.46 mm². The test results show that the modulator achieves SNR 91 db in 22 KHz audio bandwidth.