A 5GHz 90-nm CMOS all digital phase-locked loop

• An all digital phase-locked loop (ADPLL) has been implemented in a 90-nm CMOS process. It uses a phase-frequency detector (PFD) connected to two time-to-digital converters (TDC). To save power the TDCs use delay line cells with uneven delay time. During frequency acquisition an automatic tuning bank controller selects active bank of the digitally controlled oscillator (DCO), which features three separate tuning banks for both high resolution and wide frequency tuning range. To further increase the resolution a high-speed delta-sigma modulator is also used, modulating the DCO fine tuning word. The PLL achieves a measured phase noise of -125dBc/Hz at 1MHz offset from a divided-by-2 carrier frequency of 2.58GHz. The core area is 0.33mm2 and the current consumption is 30mA from a 1.2V supply.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Keyword

RF

Digitally Controlled Oscillator (DCO)

Phase Locked Loop (PLL)

Time-to-Digital Converter (TDC)

All Digital Phase-Locked Loop (ADPLL)

CMOS

Publication and Content Type

art (subject category)

ref (subject category)