All-digital TX frequency synthesizer and discrete-time receiver for Bluetooth radio in 130-nm CMOS

TLDR

The paper presents a single‑chip, fully compliant Bluetooth radio fabricated in a digital 130‑nm CMOS process. The transceiver is built entirely in digital CMOS, replacing the traditional VCO‑based synthesizer with a digitally controlled oscillator and time‑to‑digital converter, employing an all‑digital PLL with automatic compensation for modulation accuracy, a discrete‑time receiver that samples the RF signal directly, and integrated power‑management and digital baseband processing. The resulting IC occupies 10 mm² and consumes 28 mA during transmit and 41 mA during receive at 1.5 V, achieving significant area and power savings while remaining scalable to more advanced processes.

Abstract

We present a single-chip fully compliant Bluetooth radio fabricated in a digital 130-nm CMOS process. The transceiver is architectured from the ground up to be compatible with digital deep-submicron CMOS processes and be readily integrated with a digital baseband and application processor. The conventional RF frequency synthesizer architecture, based on the voltage-controlled oscillator and the phase/frequency detector and charge-pump combination, has been replaced with a digitally controlled oscillator and a time-to-digital converter, respectively. The transmitter architecture takes advantage of the wideband frequency modulation capability of the all-digital phase-locked loop with built-in automatic compensation to ensure modulation accuracy. The receiver employs a discrete-time architecture in which the RF signal is directly sampled and processed using analog and digital signal processing techniques. The complete chip also integrates power management functions and a digital baseband processor. Application of the presented ideas has resulted in significant area and power savings while producing structures that are amenable to migration to more advanced deep-submicron processes, as they become available. The entire IC occupies 10 mm/sup 2/ and consumes 28 mA during transmit and 41 mA during receive at 1.5-V supply.