ICS849N202I Datasheet, PDF (1/39 Pages) Integrated Device Technology – FemtoClock® NG Universal Frequency Translator

FemtoClock® NG Universal Frequency
Translator
ICS849N202I
DATA SHEET
General Description
The ICS849N202I is a highly flexible FemtoClock® NG general
purpose, low phase noise Universal Frequency Translator /
Synthesizer with alarm and monitoring functions suitable for
networking and communications applications. It is able to generate
any output frequency in the 0.98MHz - 312.5MHz range and most
output frequencies in the 312.5MHz - 1,300MHz range (see Table 3
for details). A wide range of input reference clocks and a range of
low-cost fundamental mode crystal frequencies may be used as the
source for the output frequency.
The ICS849N202I has three operating modes to support a very
broad spectrum of applications:
1) Frequency Synthesizer
• Synthesizes output frequencies from a 16MHz - 40MHz
fundamental mode crystal.
• Fractional feedback division is used, so there are no
requirements for any specific crystal frequency to produce the
desired output frequency with a high degree of accuracy.
2) High-Bandwidth Frequency Translator
• Applications: PCI Express, Computing, General Purpose
• Translates any input clock in the 16MHz - 710MHz frequency
range into any supported output frequency.
• This mode has a high PLL loop bandwidth in order to track input
reference changes, such as Spread-Spectrum Clock
modulation, so it will not attenuate much jitter on the input
reference.
3) Low-Bandwidth Frequency Translator
• Applications: Networking & Communications.
• Translates any input clock in the 8kHz -710MHz frequency
range into any supported output frequency.
• This mode supports PLL loop bandwidths in the 10Hz - 580Hz
range and makes use of an external crystal to provide
significant jitter attenuation.
This device provides two factory-programmed default power-up
configurations burned into One-Time Programmable (OTP) memory.
The configuration to be used is selected by the CONFIG pin. The two
configurations are specified by the customer and are programmed by
IDT during the final test phase from an on-hand stock of blank
devices. The two configurations may be completely independent of
one another.
One usage example might be to install the device on a line card with
two optional daughter cards: an OC-12 option requiring a 622.08MHz
LVDS clock translated from a 19.44MHz input and a Gigabit Ethernet
option requiring a 125MHz LVPECL clock translated from the same
19.44MHz input reference.
To implement other configurations, these power-up default settings
can be overwritten after power-up using the I²C interface and the
device can be completely reconfigured. However, these settings
would have to be re-written next time the device powers-up.
Features
• 4^TH generation FemtoClock® NG technology
• Universal Frequency Translator (UFT) / Frequency Synthesizer
• Two outputs, individually programmable as LVPECL or LVDS
• Both outputs may be set to use 2.5V or 3.3V output levels
• Programmable output frequency: 0.98MHz up to 1,300MHz
• Zero ppm frequency translation
• Two differential inputs support the following input types:
LVPECL, LVDS, LVHSTL, HCSL
• Input frequency range: 8kHz - 710MHz
• Crystal input frequency range: 16MHz - 40MHz
• Two factory-set register configurations for power-up default state
• Power-up default configuration pin or register selectable
• Configurations customized via One-Time Programmable ROM
• Settings may be overwritten after power-up via I²C
• I²C Serial interface for register programming
• RMS phase jitter at 125MHz, using a 40MHz crystal
(12kHz - 20MHz): 510fs (typical), Low Bandwidth Mode (FracN)
• RMS phase jitter at 400MHz, using a 40MHz crystal
(12kHz - 40MHz): 321fs (typical), Synthesizer Mode (Integer FB)
• Output supply voltage modes:
V_CC/V_CCA/V_CCO
3.3V/3.3V/3.3V
3.3V/3.3V/2.5V (LVPECL only)
2.5V/2.5V/2.5V
• -40°C to 85°C ambient operating temperature
• Available in lead-free (RoHS 6) package
Pin Assignment
XTAL_IN
XTAL_OUT
VCC
CLK_SEL
CLK0
nCLK0
VCC
V_EE
CLK1
nCLK1
40 39 38 37 36 35 34 33 32 31
1
30
2
29
3 ICS849N202I
28
4 _{40 Lead VFQFN}
27
5 _{6mm x 6mm x 0.925mm} 26
6
K Package
25
7
Top View
24
8
23
9
22
10
21
11 12 13 14 15 16 17 18 19 20
LOCK_IND
VCC
OE0
Q0
nQ0
VCCO
Q1
nQ1
OE1
VEE
ICS849N202CKI REVISION A SEPTEMBER 26, 2011
1
©2011 Integrated Device Technology, Inc.