LMK04808BISQE/NOPB Texas Instruments 时钟合成器/抖动清除器

1 Features 3 Description

The LMK0480x family is the industry's highest

1• Ultra-Low RMS Jitter Performance

performance clock conditioner with superior clock

– 111 fs RMS Jitter (12 kHz to 20 MHz) jitter cleaning, generation, and distribution with

– 123 fs RMS Jitter (100 Hz to 20 MHz) advanced features to meet next generation system

• Dual Loop PLLatinum™ PLL Architecture requirements. The dual loop PLLatinum™

architecture is capable of 111 fs rms jitter (12 kHz to

• PLL1 20 MHz) using a low noise VCXO module or sub-200

– Integrated Low-Noise Crystal Oscillator Circuit fs rms jitter (12 kHz to 20 MHz) using a low cost

– Holdover Mode when Input Clocks are Lost external crystal and varactor diode.

– Automatic or Manual Triggering/Recovery The dual loop architecture consists of two high•

PLL2 performance phase-locked loops (PLL), a low-noise

crystal oscillator circuit, and a high-performance

– Normalized PLL Noise Floor of –227 dBc/Hz voltage controlled oscillator (VCO). The first PLL

– Phase Detector Rate up to 155 MHz (PLL1) provides low-noise jitter cleaner functionality

– OSCin Frequency-Doubler while the second PLL (PLL2) performs the clock

generation. PLL1 can be configured to either work

– Integrated Low-Noise VCO with an external VCXO module or the integrated

• 2 Redundant Input Clocks with LOS crystal oscillator with an external tunable crystal and

– Automatic and Manual Switch-Over Modes varactor diode. When paired with a very narrow loop

bandwidth, PLL1 uses the superior close-in phase • 50 % Duty Cycle Output Divides, 1 to 1045 (Even

noise (offsets below 50 kHz) of the VCXO module or and Odd) the tunable crystal to clean the input clock. The

• 12 LVPECL, LVDS, or LVCMOS Programmable output of PLL1 is used as the clean input reference to

Outputs PLL2 where it locks the integrated VCO. The loop

• Digital Delay: Fixed or Dynamically Adjustable bandwidth of PLL2 can be optimized to clean the farout

phase noise (offsets above 50 kHz) where the • 25 ps Step Analog Delay Control.

integrated VCO outperforms the VCXO module or

• 14 Differential Outputs. Up to 26 Single Ended. tunable crystal used in PLL1.
2 Applications • Data Converter Clocking • Wireless Infrastructure • Networking, SONET/SDH, DSLAM • Medical / Video / Military / Aerospace • Test and Measurement