A 6-GHz integrated phase-locked loop using AlGaAs/GaAs heterojunction bipolar transistors

• Published in: IEEE journal of solid-state circuits Vol. 27; no. 12; pp. 1752 - 1762
• Main Authors: Buchwald, A.W., Martin, K.W., Oki, A.K., Kobayashi, K.W.
• Format: Journal Article
• Language: English
• Published: IEEE 01-12-1992
• Subjects: Circuits; Clocks; Filters; Gallium arsenide; Heterojunction bipolar transistors; Optical fiber communication; Phase detection; Phase frequency detector; Phase locked loops; Voltage-controlled oscillators
• ISSN: 0018-9200; 1558-173X
• DOI: 10.1109/4.173102

A fully integrated 6-GHz phase-locked-loop (PLL) fabricated using AlGaAs/GaAs heterojunction bipolar transistors (HBTs) is described. The PLL is intended for use in multigigabit-per-second clock recovery circuits for fiber-optic communication systems. The PLL circuit consists of a frequency quadrupling ring voltage-controlled oscillator (VCO), a balanced phase detector, and a lag-lead loop filter. The closed-loop bandwidth is approximately 150 MHz. The tracking range was measured to be greater than 750 MHz at zero steady-state phase error. The nonaided acquisition range is approximately 300 MHz. This circuit is the first monolithic HBT PLL and is the fastest yet reported using a digital output VCO. The minimum emitter area was 3 mu m*10 mu m with f/sub t/=22 GHz and f/sub max/=30 GHz for a bias current of 2 mA. The speed of the PLL can be doubled by using 1- mu m*10- mu m emitters in next-generation circuits. The chip occupies a die area of 2-mm*3-mm and dissipates 800 mW with a supply voltage of -8 V.< >