LMX2485E
- Quadruple Modulus Prescaler for Lower Divides
- RF PLL: 8/9/12/13 or 16/17/20/21
- IF PLL: 8/9 or 16/17
- Advanced Delta-Sigma Fractional Compensation
- 12-Bit or 22-Bit Selectable Fractional Modulus
- Up to 4th Order Programmable Delta-Sigma
Modulator
- Features for Improved Lock Time
- Fastlock / Cycle Slip Reduction With Integrated
Time-Out Counter Which Requires Only a
Single-Word Write
- Fastlock / Cycle Slip Reduction With Integrated
- Wide Operating Range
- LMX2485 RF PLL: 500 MHz to 3.0 GHz
- LMX2485E RF PLL: 50 MHz to 3.0 GHz
- Useful Features
- Digital Lock Detect Output
- Hardware and Software Power-Down Control
- On-Chip Input Frequency Doubler.
- RF Phase Detector Frequency up to 50 MHz
- 2.5 to 3.6 V Operation With ICC = 5.0 mA
The LMX2485 device is a low power, high performance delta-sigma fractional-N PLL with an auxiliary integer-N PLL. The device is fabricated using Texas Instruments advanced process.
With delta-sigma architecture, fractional spurs at lower offset frequencies are pushed to higher frequencies outside the loop bandwidth. The ability to push close in spur and phase noise energy to higher frequencies is a direct function of the modulator order. Unlike analog compensation, the digital feedback technique used in the LMX2485 is highly resistant to changes in temperature and variations in wafer processing. The LMX2485 delta-sigma modulator is programmable up to fourth order, which allows the designer to select the optimum modulator order to fit the phase noise, spur, and lock time requirements of the system.
Serial data for programming the LMX2485 is transferred through a three-line, high-speed (20-MHz) MICROWIRE interface. The LMX2485 offers fine frequency resolution, low spurs, fast programming speed, and a single-word write to change the frequency. This makes it ideal for direct digital modulation applications, where the N-counter is directly modulated with information. The LMX2485 is available in a 24-lead 4.0 × 4.0 × 0.8 mm WQFN package.
技術文件
| 重要文件 | 類型 | 標題 | 格式選項 | 下載最新的英文版本 | 日期 | |
|---|---|---|---|---|---|---|
| * | 資料表 | LMX2485x 3-GHz Delta-Sigma Low-Power Dual PLLatinum Frequency Synthesizer datasheet (Rev. G) | PDF | HTML | 2016/1/13 | ||
| 應用說明 | AN-1879 Fractional N Frequency Synthesis (Rev. B) | 2021/11/18 |
設計與開發
如需其他條款或必要資源,請按一下下方的任何標題以檢視詳細頁面 (如有)。
CODELOADER — CodeLoader Device Register Programming v4.19.0
The CodeLoader 4 software is used to program the LMX PLLs and LMK timing devices through either the USB or line print terminal (LPT) port of a computer. This software also provides information on how to program the device by showing the bits that are actually sent.
Which software do I use?
Product | (...) |
CLOCKDESIGNTOOL — Clock Design Tool Software
時脈設計工具軟體可協助進行零件選擇、迴路濾波器設計,以及計時裝置解決方案模擬。當您輸入所需的輸出頻率和參考頻率 (選用) 時,此工具可提供符合指定需求、分頻器值和建議迴路濾波器的 TI 裝置,以將抖動降到最低。
CLOCKDESIGNTOOL 教學影片
我應該使用哪個軟體?
產品 | 迴路濾波器和裝置配置 + 模擬 | 模擬工具 | 裝置暫存器程式化 |
LMX24xx PLL 系列 | EasyPLL | ||
LMX25xx PLL+VCO 系列 | 時脈設計工具 | ||
LMK 抖動清除器及分配器 |
TICSPRO-SW — TICS Pro GUI and Live Programming Tool for Clocking Devices
德州儀器 (TI) 的時鐘及合成器 (TICS) 專業級軟體用於編程具有以下前置字元的產品編號的評估模組 (EVM):CDC、LMK 和 LMX。這些產品包括鎖相迴路及電壓控制振盪器 (PLL+VCO)、合成器和時鐘裝置。
CLOCK-TREE-ARCHITECT — 時鐘樹架構程式設計軟體
時鐘樹架構是一款時鐘樹合成工具,可根據您的系統需求產生時鐘樹解決方案,進而簡化您的設計流程。此工具可從廣泛的計時產品資料庫中汲取資料,產生系統級多晶片計時解決方案。
PLLATINUMSIM-SW — PLL 迴路濾波器、相位雜訊、鎖定時間與雜散模擬工具
PLLATINUMSIM-SW 為一模擬工具,可讓使用者建立 PLLatinum™ 積體電路的詳細設計和模擬,包括 LMX 系列的相位鎖定迴路 (PLL) 及合成器。
| 封裝 | 針腳 | CAD 符號、佔位空間與 3D 模型 |
|---|---|---|
| WQFN (RTW) | 24 | Ultra Librarian |
訂購與品質
建議產品可能具有與此 TI 產品相關的參數、評估模組或參考設計。