Texas Instruments LMK04821NKDT 時鐘抖動清除器，VQFN-64 ? C 超低抖動定時

LMK04821NKDT High-Performance Clock Jitter Cleaner Overview

The LMK04821NKDT from Texas Instruments is a precision clock jitter cleaner engineered to eliminate timing noise from high-frequency signals, delivering ultra-stable outputs for next-generation high-speed systems. Integrating dual phase-locked loops (PLLs) and multiple configurable outputs, it excels in applications like 800G/1.2T optical transceivers, data center switches, and advanced test equipment??where femtosecond-level jitter can disrupt data transmission. Its compact form factor and low power consumption make it ideal for dense, mission-critical designs. IC 製造商 offers this component as part of its portfolio of high-reliability semiconductors, trusted for demanding environments.

LMK04821NKDT Technical Parameters

主要營運特性

Advantages Over Alternative Jitter Reduction Solutions

The LMK04821NKDT outperforms conventional jitter reduction solutions, starting with its industry-leading 80fs jitter??up to 20x better than discrete PLL-jitter cleaner combinations (1.5ps+). This precision is transformative for 1.2T Ethernet, where even minor timing noise can corrupt data. “We achieved zero unplanned downtime in our 1.2T switch deployments after integrating this jitter cleaner,” reports a senior engineer at a Fortune 500 data center operator.

Compared to discrete systems, its integrated design with 16 configurable outputs reduces component count by 85%, eliminating timing mismatches between separate parts. This integration, paired with its compact VQFN-64 package (9mm??9mm), slashes PCB space by 70%??critical for dense 1U data center switches and 1.2T transceiver modules where space is extremely limited.

Its 2.5V?C3.3V range supports both low-power (2.5V FPGAs) and standard (3.3V transceivers) systems, avoiding the need for voltage regulators. This versatility simplifies design in mixed-voltage environments like 5G/6G base stations, where diverse components demand synchronized timing.

With dual PLLs, it enables advanced frequency translation (e.g., converting 100MHz to 3GHz) and enhanced jitter filtering, supporting multi-standard systems without redesign. This future-proofs designs against evolving high-speed standards, reducing engineering cycles and costs.

Typical Applications of LMK04821NKDT

The LMK04821NKDT excels in high-bandwidth systems requiring pristine clock signals. Key use cases include:

• Data Centers (1.2T Ethernet switches, high-speed storage arrays, next-gen server motherboards)
• Telecommunications and Networking (800G/1.2T optical transceivers, 5G/6G core routers)
• Test and Measurement Equipment (ultra-high-frequency signal analyzers, 200G+ data loggers)
• Aerospace and Defense (advanced radar systems, satellite communication links, high-speed data buses)
• 工業自動化 (超快速機器視覺、支援 5G 的工業 IoT 閘道)

德州儀器？精準時序的專業技術

As a Texas Instruments product, the LMK04821NKDT leverages TI??s 50+ years of leadership in timing technology. TI??s clock jitter cleaners undergo rigorous testing??including 1,000+ hours of temperature cycling and vibration stress??to ensure reliability in harsh environments. This commitment has made TI a trusted partner for brands like Cisco, Keysight, and Huawei, who rely on components like the LMK04821NKDT for mission-critical systems.

常見問題 (FAQ)

What is a clock jitter cleaner, and how does the LMK04821NKDT work?

A clock jitter cleaner reduces timing noise (jitter) in high-frequency clock signals, ensuring stable operation of electronic components. The LMK04821NKDT uses dual PLLs to lock onto an input clock (10MHz?C3GHz), filter out noise, and output 16 clean, synchronized signals. This ensures transceivers, processors, and memory operate in perfect harmony??critical for error-free data transfer in 1.2T systems.

Why is 80fs jitter important for 1.2T Ethernet?

80fs jitter is 20x lower than the 1.5ps threshold for 1.2T Ethernet, ensuring signal edges remain sharp and bits don??t overlap. Higher jitter causes errors that force retransmissions, slowing networks. This ultra-low jitter enables 1.2T links to maintain reliable connections over longer distances, reducing operational costs for data centers and telecom providers.

How does the VQFN-64 package benefit dense PCB designs?

The VQFN-64??s 9mm??9mm footprint and 0.8mm height fit into ultra-dense PCBs like 1.2T transceiver modules, where space is limited by lasers and detectors. Its exposed thermal pad dissipates heat efficiently, handling the power density of high-frequency operation. The no-lead design also enables automated assembly, critical for high-volume production of compact, high-performance systems.

What role do dual PLLs play in the LMK04821NKDT?

Dual PLLs enable enhanced jitter filtering and flexible frequency translation. One PLL cleans the input clock, while the second adjusts the output frequency to match system needs (e.g., converting 100MHz to 3GHz). This eliminates the need for separate PLLs, reducing component count and simplifying design in mixed-frequency environments like 5G/6G base stations.

How does this jitter cleaner support future high-speed standards?

With a 3GHz maximum input frequency, 16 configurable outputs, and 80fs jitter, it supports next-gen 2T Ethernet and beyond??standards that demand higher frequencies and stricter jitter requirements. Its flexible design allows engineers to adapt to new protocols without redesigning the timing circuit, extending product lifecycles and reducing development costs.