Cubic Voltage Generation Circuit for Low-Phase Noise ATCXO Applications

A high order voltage generation circuit based on the parallel structure of differential amplifiers is introduced by studying the compensated voltage generation module in ATCXO. Unlike the traditional Gilbert multiplier cascade structure, this method effectively reduces the step-by-step amplification of noise in the circuit, thus significantly improving the phase noise performance. At the same time, the whole module can be realized with only twenty to thirty active and passive devices, without unique processes, which can simultaneously achieve low-power and low-cost design based on effective noise reduction and is more conducive to on-chip implementation. In this way, a high order voltage generation circuit is designed for a low-phase noise ATCXO. The ATCXO designed using this method has a frequency stability of ±2.2ppm and a phase noise of -133.2dBc/Hz @ 1kHz within the temperature range of -40°C to 80°C. The chip area of the high order voltage generation circuit module is 0.47×0.25 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>.