(页数;37字数:10865)摘要： 简要介绍LMX2310U/LMX2311U/LMX2312U/LMX2313U高性能频率合成器芯片的功能、内部结构、引脚排列及典型的应用电路。LMX2310/1/2 U 集成的是可选择双模数32/33 和 16/17的前置分频器。 LMX2313U集成的是可选择双模数16/17 和 8/9 的前置分频器。该器件当一个高品质的基准振荡器和一个压控振荡器组合时，就能产生一个高稳定度、噪音极低的本地振荡信号，在无线通信中用于上/下变频。通过一个三线串行口（DATA、ENABLE和CLOCK）串行数据能传入到LMX2310/1/2/3U，能直接与低压基带处理器连接。LMX2310/1/2/3U的电源电压均为 2.7V ～5.5V。
关键字：前置分频器 反馈分频器 低功耗 锁相环路 快速跟踪输出
Abstract
It briefly introduced The LMX2310/1/2/3U high performance frequency synthesizers’s
microcontroller function, internal structure, pin array and typical apply circuit. The LMX2310/1/2U use a selectable, dual modulus 32/33 and 16/17 prescaler. The LMX2313U uses a selectable,dual modulus 16/17 and 8/9 prescaler. The device,when combined with a high quality reference oscillator and a voltage controlled oscillator, generates very stable, low noise local oscillator signals for up and down conversion in wireless communication devices.
Serial data is transferred into LMX2310/1/2/3U via a threewire interface (Data, Enable, Clock) that can be directly interfaced with low voltage baseband processors. Supply voltage can range from 2.7V to 5.5V.
Key word: reference divider Feedback divider
Power-Down PPL Fastlock™ OUTPUT
1. LMX2310/1/2/3U芯片简介-------------------------------------------------------------------4
2. LMX2310/1/2/3U芯片封装与引脚功能--------------------------------------------------4
3. LMX2310/1/2/3U主要电气特性------------------------------------------------------------8
4. LMX2310/1/2/3U内部结构与工作原理 --------------------------------------------24
4．1 基准振荡器---------------------------------------------------------------------------------28
4．2 基准分频器---------------------------------------------------------------------------------28
4．3 RF前置分频器------------------------------------------------------------------------------28
4．4 可编程的反馈分频器----------------------------------------------------------------------28
4．5 相位/频率检波器---------------------------------------------------------------------------28
4．6 充电泵----------------------------------------------------------------------------------------28
4．7 串行接口-------------------------------------------------------------------------------------29
4．8 多功能输出----------------------------------------------------------------------------------29
4．8．1 模拟锁相---------------------------------------------------------------------------------29
4．8．2 数字锁相---------------------------------------------------------------------------------29
4．9 快速跟踪输出-------------------------------------------------------------------------------31
4．10 低功耗模式----------------------------------------------------------------------------------31
5. LMX2310/1/2/3U应用电路设计------------------------------------------------------------32
5．1 串行接口设计-------------------------------------------------------------------------------32
5．2 R寄存器---------------------------------------------------------------------------------------32
5．2．1 基准分频器-------------------------------------------------------------------------------33
5．2．2 相位检波器的极性-----------------------------------------------------------------------33
5．2．3 充电泵输出电流--------------------------------------------------------------------------33
5．2．4 充电泵三态输出--------------------------------------------------------------------------33
5．2．5 FoLD脚输出真值表-----------------------------------------------------------------------34
5．3 N寄存器---------------------------------------------------------------------------------------34
5．3．1 低功耗控制-------------------------------------------------------------------------------34
5．3．2 前置分频器--------------------------------------------------------------------------------34
5．3．3 B计数器------------------------------------------------------------------------------------35
5．3．4 A计数器-----------------------------------------------------------------------------------35
5．4 T寄存器---------------------------------------------------------------------------------------35
5．4．1 FoLD输出--------------------------------------------------------------------------------36
5．4．2 超时计数器------------------------------------------------------------------------------36
6. 总结------------------------------------------------------------------------------------------------------37
参考文献--------------------------------------------------------------------------------------------------37
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