General Description

The ICS813078I is a member of the HiperClocks family of high

performance clock solutions from IDT. The ICS813078I a PLL

based synchronous clock solution that is optimized for wireless

infrastructure equipment where frequency translation and jitter

attenuation is needed.

The device contains two internal PLL stages that are cascaded in

series. The first PLL stage attenuates the reference clock jitter by

using an internal or external VCXO circuit. The internal VCXO

requires the connection of an external inexpensive pullable crystal

(XTAL) to the ICS813078I. This first PLL stage (VCXO PLL) uses

external passive loop filter components which are used to

optimize the PLL loop bandwidth and damping characteristics for

the given application. The output of the first stage VCXO PLL is a

stable and jitter-tolerant 30.72MHz reference input for the second

PLL stage. The second PLL stage provides frequency translation

by multiplying the output of the first stage up to 491.52MHz or

614.4MHz. The low phase noise characteristics of the VCXO-PLL

clock signal is maintained by the internal FemtoClock™ PLL,

which requires no external components or complex programming.

Two independently configurable frequency dividers translate the

internal VCO signal to the desired output frequencies. All

frequency translation ratios are set by device configuration pins.

Supported input reference clock frequencies:

10MHz, 12.8MHz, 15MHz, 15.36MHz, 20MHz, 30.72MHz,

61.44MHz, and 122.88MHz

Supported output clock frequencies:

30.72MHz, 38.4MHz, 61.44MHz, 76.8MHz, 122.88MHz,

153.6MHz, 245.76MHz, 491.52MHz, and 614.4MHz

Features

• Nine outputs, organized in three independent output banks with

differential LVPECL and single-ended outputs

• One differential input clock can accept the following differential

input levels: LVDS, LVPECL, LVHSTL

• One single-ended clock input

• Frequency generation optimized for wireless infrastructure

• Attenuates the phase jitter of the input clock signal by using

low-cost pullable fundamental mode crystal (XTAL)

• Internal Femtoclock frequency multiplier stage eliminates the

need for an expensive external high frequency VCXO

• LVCMOS levels for all control I/O

• RMS phase jitter @ 122.88MHz, using a 30.72MHz crystal

(12kHz to 20MHz): 1.1ps rms (typical)

• RMS phase jitter @ 61.44MHz, using a 30.72MHz crystal

(12kHz to 20MHz): 0.97ps rms (typical)

• VCXO PLL bandwidth can be optimized for jitter attenuation and

reference frequency tracking using external loop filter

components

• PLL fast-lock control

• PLL lock detect output

• Absolute pull range is +/-50 ppm

• Full 3.3V supply voltage

• -40°C to 85°C ambient operating temperature

• Available in lead-free (RoHS 6) package

• For replacement device use 8T49N285-dddNLGI