Abstract—Bandpass ADC is well known to be adopted in the narrowband receiver design in order to reduce the system complexity, increase integration and improve performance by digitizing the bandpass signal directly without prior conversion to baseband. A fully differential feedforward fourth-order continuous-time bandpass delta-sigma modulator is presented. The proposed single-bit modulator can receive 172.8 kHz IF signals by using an oversampling clock frequency of 5.53 MHz with an OSR of 128. Simulated result showing that dynamic range of 78dB within bandwidth of 21.6 kHz is achieved and the current consumption is around 1.2mA at 1.5V power supply. The design had been implemented in 0.13µm 1P6M CMOS process with MIM capacitors.
Index Terms—Analog-to-digital conversion, bandpass delta-sigma modulator, continuous-time
The authors are with Institute of Microelectronics, A*STAR, Singapore117685 (e-mail: limhj@ime.a-star.edu.sg, ngsys@ime.a-star.edu.sg, jemk@ime.a-star.edu.sg).
Cite: Huey Jen Lim, Simon Sheung Yan Ng and Minkyu Je, "Bandpass Continuous-Time Delta-Sigma Modulator for Wireless Receiver IC," International Journal of Information and Electronics Engineering vol. 3, no. 1, pp. 4-7, 2013.