FemtoClock NG Clock 8V49NS0412 Generator with Four Dividers Datasheet Description Features Eleven differential LVPECL and LVDS outputs with The 8V49NS0412 is a clock generator with four output dividers: programmable voltage swings three integers, and one that is either integer or fractional. When used with an external crystal, the 8V49NS0412 generates One LVCMOS output: Input reference can be passed to this high-performance timing for the communications and datacom output markets, especially for applications that demand extremely low The clock input operates in full differential mode (LVDS, phase noise, such as 10GE, 40GE, 100G, and 400GE. LVPECL) or single-ended LVCMOS mode The 8V49NS0412 provides versatile frequency configurations and Driven from a crystal or differential clock input output formats, and is optimized to deliver excellent phase noise 2.42.5GHz PLL frequency range supports Ethernet, SONET, performance. The device delivers an optimum combination of high and CPRI frequency plans clock frequency and low phase noise performance, combined with Four Integer output dividers with a range of output divide ratios high power supply noise rejection. (see Table 5) The 8V49NS0412 supports two types of output levels: LVPECL or One Fractional output divider can generate any desired output LVDS on eleven of its outputs. In addition, the device has a single frequency LVCMOS output that can provide a generated clock, or act as a Support of output power-down reference bypass output. Excellent clock output phase noise: The device can be configured to deliver specific configurations Offset Output Frequency Single-side Band Phase Noise 2 under pin control only, or additional configurations through an I C 100kHz 156.25MHz -143dBc/Hz 2 serial interface by external processor, or an external I C EEPROM RMS phase noise, 12kHz to 20MHz integration range: to loading the configuration. 110fs (maximum) at 156.25MHz Selected configurations can be controlled via the control input Typical Applications pins without need for serial port access 2 LVCMOS compatible I C serial interface gives access to 10G/40G/100/400G Ethernet additional configuration by external processor or loading the Fiber optics 2 configuration from an external I C EEPROM, or in combination Gigabit Ethernet, Terabit IP switches/routers with the control input pins CPRI Interfaces Single 3.3V supply voltage 64-VFQFN 9 9 mm, lead-free (RoHS 6) package -40C to 85C ambient operating temperature 2021 Renesas Electronics Corporation 1 R31DS0021EU0800 April 28, 20218V49NS0412 Datasheet Contents Description 1 Typical Applications . 1 Features 1 Block Diagram . 3 Pin Assignments 4 Pin Descriptions 4 Principles of Operation . 7 Pin versus Register Control 7 Input Clock Selection (REF SEL) 8 Prescaler and PLL Configuration 8 PLL Loop Bandwidth 9 Output Divider Frequency Sources . 9 Integer Output Dividers (Banks A, B, C, and D) 10 Fractional Output Divider (Bank D) 11 Output Drivers 11 Pin Control of the Output Frequencies and Protocols . 11 Device Start-up and Reset Behavior . 14 Serial Control Port Description . 14 Serial Control Port Configuration Description 14 2 C Mode Operation . 14 I 2 I C Master Mode Operation and Device Start-up Behavior . 15 Register Descriptions . 17 Absolute Maximum Ratings 30 DC Electrical Characteristics . 31 AC Electrical Characteristics . 36 Phase Noise Plots . 38 Applications Information . 41 Recommendations for Unused Input and Output Pins . 41 Inputs 41 Outputs . 41 Overdriving the XTAL Interface . 41 Wiring the Differential Input to Accept Single-Ended Levels . 42 3.3V Differential Clock Input Interface 43 LVDS Driver Termination . 44 Termination for 3.3V LVPECL Outputs . 46 VFQFN EPAD Thermal Release Path . 47 Schematic and Layout Recommendations 48 Power Dissipation and Thermal Considerations . 50 Example 1. LVPECL, 750mV Output Swing . 50 Example 2. LVDS, 350mV Output Swing . 52 Reliability Information . 53 Package Outline Drawings . 53 Marking Diagram 54 Ordering Information . 54 Errata . 54 Recommendations 54 Revision History . 55 2021 Renesas Electronics Corporation 2 R31DS0021EU0800 April 28, 2021