关于锁相环芯片的外部环路滤波电路的问题

一只小鱼儿

锁相环芯片的外部环路滤波电路接在了CPOUT管脚，手册上推荐该滤波电路需要靠近管脚放置，想请教一下，外部环路滤波电路如果不靠近CPOUT管脚放置，会有什么影响吗？

超級狗

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: b0 V" J# f% ^1 Z& V6 kCPOUT
; t7 L/ R$ X( oCharge-Pump Output. Connect a PLL loop filter as a shunt C and a shunt combination of series R and C.

超級狗

踢哀（TI）E2E 論壇
As for the CPout pin, this is the charge pump output which can range from 0 to 2.5V, as it is powered by a 2.5V regulator. If this voltage falls below 0.5 V or goes above 2.0 V, then the Vtune lock detect will consider this unlocked. When the VCO is calibrated, this targes a voltage of around 1.2 volts, but this voltage can "tune" to adjust the VCO frequency.

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一只小鱼儿

超級狗 发表于 2024-9-23 12:50
踢哀（TI）E2E 論壇
: |' u' A+ ^% h8 y; zAs for the CPout pin, this is the charge pump output which can range from 0 to 2 ...

1 C1 ^8 Z; W5 V. d* g7 K* k# ^感谢，刚看TI的资料，这应该会对相位噪声有点影响。