字数:9643.页数:27
摘 要
LMX2350/2352属于单片集成电路分数Ｎ／整数Ｎ位频率合成器系列的一部分,用于一个本机振荡器子系统设计出一个无线电收发机。它是利用国标为0.5μABiC V硅BICMOS制造而成的。LMX2350/2352包含双模预定标器以及在射频分频器中按模计算15或16分数的补偿电路。16/17或32/33前置分频比可以用于LMX2350/LMX2352电路,它供应给8/9或16/17前置分频比. 中频电路用于LMX2350和LMX2352包含一个８／９预定标器，并且完成编程.LMX2350/2352采用分数为Ｎ位锁相环技术,可以产生高稳定性,低噪声控制信号,可用于超高频和甚高频电压控制振荡器（vcos）。
用于射频PLL，高灵活性的16位电平可编程充电泵,电源电流大小从100μA到1.6mA。二个不受控制的CMOS输出,可作为外部控制信号，或对 FastLock方式进行组合。串行数据是经三相的分界面（Data，LE，Clock）传递到LMX2350／LMX2352当中。电源电压可取2.7V到5.5V。LMX2350／LMX2352系列特征是电流消耗十分低；一般当电压为3.0V时LMX2350（2.5GHZ）为6.5mA，LMX2352(1.2GHZ)为4.75mA,LMX2350／2352电路是集成在一个24管脚TSSOP和CSP表面塑料封装当中。
关键词：频率合成器、锁相环、可编程
Abstract
The LMX2350/2352 is part of a family of monolithic integrated fractional N/ Integer N frequency synthesizers designed to be used in a local oscillator subsystem for a radio transceiver. It is fabricated using National’s 0.5μ ABiC V silicon BiCMOS process. The LMX2350/2352 contains dual modulus prescalers along with modulo 15 or 16 fractional compensation circuitry in the RF divider. A 16/17 or 32/33 prescale ratio can be selected for the LMX2350, and the LMX2352 provides 8/9 or 16/17 prescale ratios. The IF circuitry for both the LMX2350 and LMX2352 contains an 8/9 prescaler, and is fully programmable. Using a fractional N phase locked loop technique, the LMX2350 /52 can generate very stable low noise control signals for UHF and VHF voltage controlled oscillators (VCOs).
For the RF PLL, a highly flexible 16 level programmable charge pump supplies output current magnitudes from 100μA to 1.6mA. Two uncommitted CMOS outputs can be used to provide external control signals, or configured to FastLock mode. Serial data is transferred into the LMX2350/2352 via a three wire interface (Data, LE, Clock). Supply voltage can range from 2.7 V to 5.5 V. The LMX2350/ LMX2352 family features very low current consumption; typically LMX2350 (2.5 GHz) 6.5 mA, LMX2352 (1.2 GHz) 4.75mA at 3.0V. The LMX2350/2352 are available in a 24-pin TSSOP and 24-pin CSP surface mount plastic package.
key words：frequency synthesizers 、phase locked loop、programmable
目 录
LMX2350和LMX2352简介
1.0 基本描述
1.1 功能块……………………………………………………………………………………4
1.2 LMX2350/LMX2352引脚说明 ……………………………………………………………4
1.3 大绝对额定值…………………………………………………………………………5
1.4 推荐工作件………………………………………………………………………………6
1.5 电气特征…………………………………………………………………………………6
1.6 电荷泵详细说明…………………………………………………………………………8
1.7 RF灵敏度测试块…………………………………………………………………………9
1.8 典型特征 ………………………………………………………………………………10
2. 功能描述 …………………………………………………………………………………14
2.0 常规 ……………………………………………………………………………………14
2.1 基准振荡器输入端 ……………………………………………………………………14
2.2 基准分频器（R计数器）………………………………………………………………15
2.3 可编程分频器（N位计数器）…………………………………………………………15
2.4 相位/频率检波器………………………………………………………………………15
2.5 电荷泵 …………………………………………………………………………………16
2.6 倍压器 …………………………………………………………………………………16
2.7 微带线串行接口 ………………………………………………………………………16
2.8 FO/LD多功能输出………………………………………………………………………16
2.9 电源控制装置 …………………………………………………………………………16
3. 编程部分 …………………………………………………………………………………17
3.0 寄存器输入数据 ………………………………………………………………………17
3.1 寄存器分布 ……………………………………………………………………………17
4. 可编程分配器（R计数器）……………………………………………………………17
4.0 IF—R寄存器 ……………………………………………………………………………17
4.1 RF—R寄存器 ……………………………………………………………………………18
5. 可编程分配器（N计数器）……………………………………………………………19
5.0 IF—N寄存器……………………………………………………………………………19
5.1 RF—N寄存器……………………………………………………………………………19
5.2 CMOS ……………………………………………………………………………………21
5.3 串行数据输入时序 ……………………………………………………………………21
5.4 锁定检测数字滤波器 …………………………………………………………………22
5.5 模拟锁定检测滤波器 …………………………………………………………………23
5.6 典型锁定检测滤波器 …………………………………………………………………23
5.7 LMX2350/LMX2352外形尺寸图…………………………………………………………24
6.总结……………………………………………………………………………………………26
参考文献 ………………………………………………………………………………………26
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