Description
The 8V49NS0312 is a Clock Generator with four output dividers:
three integer and one that is either integer or fractional. When used
with an external crystal, the 8V49NS0312 generates
high-performance timing geared towards the communications and
datacom markets, especially for applications that demand extremely
low phase noise, such as 10, 40, and 100GE.
The 8V49NS0312 provides versatile frequency configurations and
output formats and is optimized to deliver excellent phase noise
performance. The device delivers an optimum combination of high
clock frequency and low phase noise performance, combined with
high power supply noise rejection.
The 8V49NS0312 supports two types of output levels: LVPECL or
LVDS on eleven of its outputs. In addition, there is a single LVCMOS
output that has the option of providing a generated clock or acting as
a reference bypass output.
The device can be configured to deliver specific output
configurations under pin control only or additional configurations
through an I2
C serial interface.
It is offered in a lead-free (RoHS6) 64-VFQFPN package.

Features
▪ Eleven differential LVPECL, LVDS outputs with programmable
voltage swings
▪ One LVCMOS output
— Input reference maybe bypassed to this output
▪ The clock input operates in full differential mode (LVDS, LVPECL)
or single-ended LVCMOS mode
▪ Driven from a crystal or differential clock input
▪ 2.4-2.5GHz PLL frequency range supports Ethernet, SONET and
CPRI frequency plans
▪ Four Integer output dividers with a range of output divide ratios
(see Table 7)
▪ One Fractional Output divider can generate any desired output
frequency
▪ Support of output power-down
▪ Excellent clock output phase noise
Offset Output Frequency Single-side Band Phase Noise
100kHz 156.25MHz -143dBc/Hz
▪ Phase Noise RMS, 156.25MHz, 12kHz to 20MHz integration
range: 110fs (maximum)
▪ Select configurations may be controlled via the use of control
input pins without need for serial port access
▪ LVCMOS compatible I2
C serial interface gives access to
additional configurations either alone or in combination with the
control input pins
▪ Single 3.3V supply voltage
▪ Lead-free (RoHS 6) 64-VFQFPN packaging
▪ -40°C to 85°C ambient operating temperature