ADCLK846BCPZ屬于集成電路（IC）的時(shí)鐘緩沖器驅(qū)動(dòng)器。由亞德諾半導(dǎo)體技術(shù)有限公司制造生產(chǎn)的ADCLK846BCPZ時(shí)鐘緩沖器，驅(qū)動(dòng)器時(shí)鐘緩沖器和驅(qū)動(dòng)器集成電路產(chǎn)品族中的產(chǎn)品用于幫助信號(hào)在系統(tǒng)中傳輸，常用作頻率/時(shí)間參考信號(hào)，以同步系統(tǒng)內(nèi)的活動(dòng)。盡管這些器件最常用到的功能就是緩沖（即，為使信號(hào)不受驅(qū)動(dòng)負(fù)載的影響而從某個(gè)信號(hào)源復(fù)制信號(hào)），但是該產(chǎn)品族中的某些器件還能執(zhí)行其他功能，例如選擇性改變緩沖信號(hào)路徑、按某個(gè)整數(shù)值分割信號(hào)頻率，或進(jìn)行所用電信號(hào)格式轉(zhuǎn)換。

CIRCUIT DESCRIPTION

The circuit in Figure 1 was constructed by connecting the respective evaluation boards for the individual products. Connections were made with matched cable lengths. The first of three basic requirements to synchronize multiple AD9910’s is to provide a co-incident reference clock (REF CLK).

The setup uses the AD9520 as the REF CLK source for each AD9910 DDS. The AD9520 runs off an external crystal and the internal PLL. The AD9520 distributes phase aligned 1 GHz REF CLKs (PECL outputs) to all four AD9910 evaluation boards. It also provides a CMOS output clock to the Tektronix DG2020A data pattern generator for the IO_UPDATE.

CIRCUIT FUNCTION AND BENEFITS

Synchronization of multiple DDS devices allows precise digital tuning control of the phase and amplitude across multiple frequency carriers. This type of control is useful in radar applications and quadrature (I/Q) upconversion for side-band suppression.

The circuit in Figure 1 demonstrates how to synchronize four AD9910 1 GSPS, DDS chips using the AD9520 clock generator and the ADCLK846 clock fanout buffer. The result is precise phase alignment between the clock and output signals of four AD9910 devices.