A 1.75 mW 1.1 GHz Semi-Digital Fractional-N PLL With TDC-Less Hybrid Loop Control

作者：Sun, Yuanfeng^*; Zhang, Zhuo; Xu, Ni; Wang, Min; Rhee, Woogeun; Oh, Tae-Young; Wang, Zhihua

来源：IEEE Microwave and Wireless Components Letters, 2012, 22(12): 654-656.

DOI：10.1109/LMWC.2012.2228178

• All-digital PLL
• CMOS integrated circuits
• fractional-N
• frequency synthesizer
• PLL

A 1.1 GHz semi-digital fractional-N PLL without the time-to-digital converter (TDC) whose resolution and linearity heavily depends on process and temperature variations is implemented in 65 nm CMOS. A hybrid loop control with a fully differential proportional-gain path and embedded finite-impulse response (FIR) filtering achieves linear phase tracking as well as good technology scalability, having a small analog loop filter area less than 0.01 mm(2). The use of the hybrid FIR filter not only suppresses out-of-band quantization noise of the Delta Sigma modulator but also improves the linearity of the proportional-gain path. The TDC-less semi-digital PLL consumes 1.75 mW from a 0.9 V supply voltage, achieving significant power reduction compared to conventional all-digital PLLs.

• 出版日期2012-12
• 单位清华大学