參數(shù)資料
型號(hào): LMX2370
廠商: National Semiconductor Corporation
英文描述: PLLatinum Dual Frequency Synthesizer for RF Personal Communications(PLLatinum技術(shù)用于射頻個(gè)人通訊的雙通道頻率合成器)
中文描述: PLLatinum雙頻率合成射頻個(gè)人通信(PLLatinum技術(shù)用于射頻個(gè)人通訊的雙通道頻率合成器)
文件頁(yè)數(shù): 22/24頁(yè)
文件大?。?/td> 516K
代理商: LMX2370
Application Information
(Continued)
FASTLOCK CIRCUIT IMPLEMENTATION
A diagram of the Fastlock scheme as implemented in Na-
tional Semiconductors LMX233xA PLL is shown in Figure 5
When a new frequency is loaded, and the RF Icp
bit is set
high the charge pump circuit receives an input to deliver 4
times the normal current per unit phase error while an open
drain NMOS on chip device switches in a second R2 resistor
element to ground. The user calculates the loop filter compo-
nent values for the normal steady state considerations. The
device configuration ensures that as long as a second iden-
tical damping resistor is wired in appropriately, the loop will
lock faster without any additional stability considerations to
account for. Once locked on the correct frequency, the user
can return the PLL to standard low noise operation by send-
ing a MICROWIRE instruction with the RF Icp
o
bit set low.
This transition does not affect the charge on the loop filter
capacitors and is enacted synchronous with the charge
pump output. This creates a nearly seamless change be-
tween Fastlock and standard mode.
DS101026-43
FIGURE 4. Open Loop Response Bode Plot
DS101026-44
FIGURE 5. Fastlock PLL Architecture
L
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相關(guān)PDF資料
PDF描述
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LMX2485_0610 50 MHz - 3.0 GHz High Performance Delta-Sigma Low Power Dual PLLatinum⑩ Frequency Synthesizers with 800 MHz Integer PLL
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參數(shù)描述
LMX2370SLBX 功能描述:IC FREQ SYNTH DUAL 24LAMINATECSP RoHS:否 類(lèi)別:集成電路 (IC) >> 時(shí)鐘/計(jì)時(shí) - 時(shí)鐘發(fā)生器,PLL,頻率合成器 系列:PLLatinum™ 標(biāo)準(zhǔn)包裝:39 系列:- 類(lèi)型:* PLL:帶旁路 輸入:時(shí)鐘 輸出:時(shí)鐘 電路數(shù):1 比率 - 輸入:輸出:1:10 差分 - 輸入:輸出:是/是 頻率 - 最大:170MHz 除法器/乘法器:無(wú)/無(wú) 電源電壓:2.375 V ~ 3.465 V 工作溫度:0°C ~ 70°C 安裝類(lèi)型:* 封裝/外殼:* 供應(yīng)商設(shè)備封裝:* 包裝:*
LMX2370SLDX 功能描述:IC FREQ SYNTH DUAL 24LAMINATECSP RoHS:否 類(lèi)別:集成電路 (IC) >> 時(shí)鐘/計(jì)時(shí) - 時(shí)鐘發(fā)生器,PLL,頻率合成器 系列:PLLatinum™ 標(biāo)準(zhǔn)包裝:39 系列:- 類(lèi)型:* PLL:帶旁路 輸入:時(shí)鐘 輸出:時(shí)鐘 電路數(shù):1 比率 - 輸入:輸出:1:10 差分 - 輸入:輸出:是/是 頻率 - 最大:170MHz 除法器/乘法器:無(wú)/無(wú) 電源電壓:2.375 V ~ 3.465 V 工作溫度:0°C ~ 70°C 安裝類(lèi)型:* 封裝/外殼:* 供應(yīng)商設(shè)備封裝:* 包裝:*
LMX2370TM 功能描述:IC FREQ SYNTH DL 2.5GHZ 20TSSOP RoHS:否 類(lèi)別:集成電路 (IC) >> 時(shí)鐘/計(jì)時(shí) - 時(shí)鐘發(fā)生器,PLL,頻率合成器 系列:PLLatinum™ 標(biāo)準(zhǔn)包裝:39 系列:- 類(lèi)型:* PLL:帶旁路 輸入:時(shí)鐘 輸出:時(shí)鐘 電路數(shù):1 比率 - 輸入:輸出:1:10 差分 - 輸入:輸出:是/是 頻率 - 最大:170MHz 除法器/乘法器:無(wú)/無(wú) 電源電壓:2.375 V ~ 3.465 V 工作溫度:0°C ~ 70°C 安裝類(lèi)型:* 封裝/外殼:* 供應(yīng)商設(shè)備封裝:* 包裝:*
LMX2370TMX 功能描述:IC FREQ SYNTH DL 2.5GHZ 20-TSSOP RoHS:否 類(lèi)別:集成電路 (IC) >> 時(shí)鐘/計(jì)時(shí) - 時(shí)鐘發(fā)生器,PLL,頻率合成器 系列:PLLatinum™ 標(biāo)準(zhǔn)包裝:39 系列:- 類(lèi)型:* PLL:帶旁路 輸入:時(shí)鐘 輸出:時(shí)鐘 電路數(shù):1 比率 - 輸入:輸出:1:10 差分 - 輸入:輸出:是/是 頻率 - 最大:170MHz 除法器/乘法器:無(wú)/無(wú) 電源電壓:2.375 V ~ 3.465 V 工作溫度:0°C ~ 70°C 安裝類(lèi)型:* 封裝/外殼:* 供應(yīng)商設(shè)備封裝:* 包裝:*
LMX2370TMX/NOPB 制造商:Texas Instruments 功能描述:PLL Frequency Synthesizer Dual 45MHz to 2500MHz 20-Pin TSSOP T/R