A 0.4V 4.8μW 16MHz CMOS crystal oscillator achieving 74-fold startup-time reduction using momentary detuning
A 0.4V 4.8μW 16MHz CMOS crystal oscillator achieving 74-fold startup-time reduction using momentary detuning
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0.4V 4.8μW 16MHz CMOS 晶体振荡器通过瞬时失谐实现启动时间缩短 74 倍
DOI：
10.1109/iscas.2017.8051002
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
R. Martins
中科院分区：
文献类型：
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作者：
Ka;Pui;R. Martins
对于超低功率无线电，晶体振荡器的长启动时间决定了它们的开关延迟，并限制了它们的功率效率。本文介绍了一种65 nm CMOS16 MHz晶体振荡器的设计，该振荡器采用瞬时失谐方案来加速启动瞬变。具体地说，在启动阶段，偏置电流(266pF)和负载电容器(每个8.5pF)被同时放大，使得振荡回路的等效负阻可以瞬间增强，导致启动时间(37ms→0.5ms)缩短74倍，而在0.4V时仅消耗53.2nJ。此外，基于时间的控制器自动将振荡器驱动到稳定状态，这需要较小的偏置电流(12μΑ)来维持振荡，并需要较小的负载电容(5pF)来恢复适当的振荡频率。在1 kHz偏移量下，模拟的相位噪声为−128.2dBc/Hz，FOM为265.5dBc/Hz。
For ultra-low-power radios, the long startup time of the crystal oscillator dominates their on-off latency and limits their power efficiency. This paper describes the design of a 65nm CMOS 16MHz crystal oscillator, featuring a momentary detuning scheme to accelerate the startup transient. Specifically, during the startup phase, the bias current (266μΑ) and loading capacitors (8.5pF each) are enlarged concurrently such that the equivalent negative resistance of the oscillation loop can be momentarily enhanced, resulting in 74-fold reduction of the startup time (37ms → 0.5ms), while consuming just 53.2nJ at 0.4V. Also, a time-based controller automatically drives the oscillator into the steady state, which entails a smaller bias current (12μΑ) to sustain the oscillation, and smaller loading capacitors (5pF) to recover the proper oscillating frequency. The simulated phase noise exhibits −128.2dBc/Hz at 1kHz offset, resulting in a FoM of 265.5dBc/Hz.