AU5411
High-performance 1:4 LVDS clock buffer with <50fs additive jitter, supporting up to 2GHz for clock distribution.
Product Overview
Description
The AU5411 is a high-performance 1:4 LVDS clock buffer designed for distributing low-jitter clock signals to multiple loads. It features ultra-low additive jitter of less than 50 femtoseconds, preserving the quality of the input clock signal.
Supporting input and output frequencies up to 2GHz, the AU5411 is suitable for high-speed networking, data center, and communication applications. The device accepts differential LVDS, LVPECL, or CML inputs and provides four identical LVDS output pairs.
The AU5411 operates from a 2.5V or 3.3V supply and is available in a compact 3x3mm QFN package. It features a synchronous output enable control and is pin-compatible with industry-standard buffers.
Product Series
AU
Primary Application
Clock distribution in networking equipment
Key Features
- Ultra-low <50fs additive jitter
- Wide DC to 2GHz frequency range
- Four identical LVDS outputs
- Flexible LVDS/LVPECL/CML input
- Synchronous output enable
- Pin-compatible with industry standards
- Industrial temperature range -40°C to +85°C
- Compact 3x3mm QFN package
Specifications
| Input Frequency | DC to 2GHz |
|---|---|
| Output Frequency | DC to 2GHz |
| Additive Jitter | <50fs RMS |
| Outputs | 4 LVDS pairs |
| Input Types | LVDS/LVPECL/CML |
| Output Types | LVDS |
| Supply Voltage | 2.5V/3.3V |
| Propagation Delay | 1.2ns typical |
| Package | 3x3mm QFN-16 |
Applications
Clock distribution in networking equipment
Communication and interface
FPGA and ASIC clock fanout
Electronic system design
High-speed ADC/DAC clocking
Data acquisition and conversion
Server and data center clock trees
Electronic system design
Test and measurement systems
Data acquisition and conversion
Wireless infrastructure clocking
Electronic system design
FAE Expert Insights
"The AU5411 is an excellent choice for clock distribution when you need to fan out a precision clock to multiple loads. In my experience, the <50fs additive jitter is among the best in its class - I've measured actual performance around 30-40fs in well-designed systems. This means you can cascade multiple buffers without significant jitter accumulation. The flexible input stage is a nice feature - it accepts LVDS, LVPECL, or CML without external components, simplifying BOM. The pin compatibility with popular industry buffers makes it an easy drop-in replacement with cost savings. One practical tip: the output enable is synchronous, so you won't get runt pulses when enabling/disabling outputs - important for systems that need dynamic clock gating."
Ultra-low additive jitter clock buffer ideal for distributing precision clocks to multiple loads
— David Liu, BeiLuo
Frequently Asked Questions
What is additive jitter and why is it important?
Additive jitter is the additional jitter introduced by a clock buffer beyond the input clock jitter. The AU5411's <50fs additive jitter ensures minimal degradation when distributing clocks to multiple loads. This is critical for high-speed applications like 10G/25G Ethernet and high-speed ADC/DAC systems where total jitter budget is tight.
Choose AU5411 for applications requiring minimal jitter degradation in clock distribution.
What input types does AU5411 support?
The AU5411 supports multiple differential input types: LVDS (Low-Voltage Differential Signaling), LVPECL (Low-Voltage Positive Emitter-Coupled Logic), and CML (Current Mode Logic). This flexibility allows the buffer to accept clocks from various sources without external level translation circuits. The input type is automatically detected or can be configured through pin strapping.
AU5411 accepts LVDS, LVPECL, or CML inputs without external components.
How many loads can AU5411 drive?
The AU5411 provides 4 identical LVDS output pairs, each capable of driving one standard LVDS load (100Ω differential termination). For applications requiring more outputs, multiple AU5411 devices can be cascaded with minimal jitter accumulation due to the low additive jitter. The outputs can also drive multiple loads in a daisy-chain configuration, though this may affect signal integrity at high frequencies.
AU5411 drives 4 LVDS loads; cascade multiple devices for larger fanout.
What is the maximum frequency for AU5411?
The AU5411 supports input and output frequencies from DC to 2GHz. At 2GHz, the device maintains excellent signal integrity with fast rise/fall times (typically <200ps). For optimal performance, proper PCB layout with controlled impedance traces (100Ω differential) is essential. The device is suitable for high-speed applications including 10G Ethernet, PCIe Gen3, and high-speed serial links.
AU5411 supports up to 2GHz, suitable for high-speed networking applications.
How do I terminate AU5411 outputs?
AU5411 LVDS outputs require standard LVDS termination: 100Ω differential resistor placed at the receiver end of the trace. For point-to-point connections, place the termination resistor at the far end. For multi-drop configurations, termination may be needed at both ends depending on trace length. The AU5411 outputs are current-mode and require proper termination for correct voltage levels and signal integrity.
Use 100Ω differential termination at the receiver for proper LVDS signaling.