公开(公告)号：US06642800B2

公开(公告)日：2003-11-04

申请号：US10116555

申请日：2002-04-04

申请人： Oleg Drapkin ,  Chak Cheung Ho ,  Ngar Sze Chan ,  Grigori Temkine ,  Ho Ming Wan

发明人： Oleg Drapkin ,  Chak Cheung Ho ,  Ngar Sze Chan ,  Grigori Temkine ,  Ho Ming Wan

IPC分类号： H03L706

CPC分类号： H03L7/235 ,  H03L7/081 ,  H03L7/0812 ,  H03L7/18 ,  H03L7/1974

摘要： A spurious-free fractional-N frequency synthesizer circuit is disclosed. The synthesizer circuit includes a multi-phase network circuit operative to provide output signals that are at least a 1/(2n+1)) fractional version of the input signal. The synthesizer circuit includes a phase lock loop (PLL) circuit, with the multi-phase network circuit being coupled to the negative feedback loop of the PLL. The multi-phase network circuit includes a smoothing circuit that removes any jitter present at the output of the PLL.

摘要翻译： 公开了一种无杂散分数N频率合成器电路。 合成器电路包括多相网络电路，其操作以提供输入信号的至少1 /（2n + 1））分数版本的输出信号。 合成器电路包括锁相环（PLL）电路，多相网络电路耦合到PLL的负反馈环路。 多相网络电路包括一个平滑电路，其消除存在于PLL输出端的任何抖动。

公开(公告)号：US20090146749A1

公开(公告)日：2009-06-11

申请号：US11952127

申请日：2007-12-06

申请人： Chik Wai Ng ,  Yat To Wong ,  Ho Ming Wan ,  David Kwok Kuen Kwong

发明人： Chik Wai Ng ,  Yat To Wong ,  Ho Ming Wan ,  David Kwok Kuen Kwong

IPC分类号： H03K3/26

CPC分类号： H03K4/501

摘要： An oscillator operates at a very low voltage yet has a duty cycle that is set by a ratio of capacitors that are charged and discharged. Sub-threshold p-channel transistors conduct sub-threshold currents below the normal threshold voltage, and drive set and reset inputs of a set-reset S-R latch. The S-R latch drives the oscillator outputs. The oscillator outputs feed back to charging p-channel transistors that charge one plate of the capacitors. During half of the cycle, the charging p-channel transistor is off, allowing one plate of the capacitors to discharge through an n-channel discharge transistor. After a period of discharge determined by the capacitance of the capacitor, the gate of a sub-threshold p-channel transistor falls enough for sub-threshold current to flow, triggering the set or reset input of the S-R latch. Since sub-threshold currents are needed to toggle the S-R latch, the oscillator begins to oscillate below the threshold voltage.

摘要翻译： 振荡器在非常低的电压下工作，但是具有由充电和放电的电容器的比率设定的占空比。 子阈值p沟道晶体管导通低于正常阈值电压的次阈值电流，以及设置复位S-R锁存器的驱动器设置和复位输入。 S-R锁存器驱动振荡器输出。 振荡器输出反馈给对一个电容器板充电的p沟道晶体管。 在半周期中，充电p沟道晶体管截止，允许电容器的一个板通过n沟道放电晶体管放电。 在通过电容器的电容确定的放电周期之后，子阈值p沟道晶体管的栅极对于亚阈值电流流下来足以触发S-R锁存器的置位或复位输入。 由于需要次阈值电流来切换S-R锁存器，所以振荡器开始振荡低于阈值电压。