Integrated DeviceTechnology
Integrated DeviceTechnology
FemtoClock
®
NG
Universal Frequency Translators
Addressing the Frequency Translation and Jitter
Attenuation Needs of the Most Demanding Applications
POWER MANAGEMENT | ANALOG & RF | INTERFACE & CONNECTIVITY |
CLOCKS & TIMING
| MEMORY & LOGIC | TOUCH & USER INTERFACE | VIDEO & DISPLAY | AUDIO
FUNCTIONS
IDT FemtoClock
®
NG Universal Frequency
Translator products offer:
• Frequency synthesis
• High-bandwidth frequency translation
• Low-bandwidth frequency translation
and jitter attenuation
BENEFITS AND FEATURES
• Fully programmable clock source
• Any frequency in to any frequency out
• Input frequency range: 8 kHz to 710 MHz
• Output frequency range: 1 MHz to 1300 MHz
• Two clock inputs with automatic hitless switching
• Two outputs, supporting single-ended, LVPECL
or LVDS levels
• On-die non-volatile memory allows device to
be fully functional at power-up without requiring
complicated user programming
• Very low RMS jitter on all outputs
• I
2
C programming interface
• -40˚C to +85˚C temperature range
• 40-Lead VFQFN package, 6x6 mm
• Available in Lead-Free (RoHS 6) package
TARGET APPLICATIONS
• Communication and wireless systems
• ADC clocking
• Industrial automation
• Video and image processing systems
• Medical devices
• Test and instrumentation
• Serial RapidIO 1.3 and 2.0
• Jitter attenuation
• Phase-noise sensitive applications
• Enterprise Networking
Description
IDT FemtoClock
®
NG Universal Frequency Translators (UFT) cover all your frequency synthesis
and translation needs. As a frequency synthesizer, a low-cost, readily-available fundamental-
mode crystal can be used to generate any output frequency from 1MHz to 1.3GHz. The internal
architecture of the device allows any frequency of crystal from 16MHz to 40MHz to be used re-
gardless of the frequency desired.
As a frequency translator, this family of devices accepts 1 or 2 input reference clocks from 8 kHz
to 710 MHz, switching between them as necessary and generates any output frequency from
1 MHz to 1.3 GHz with no frequency translation error in most cases. Two different pin-selectable
configurations may be pre-loaded into the internal One-Time Programmable (OTP) non-volatile
memory for automatic operation directly from power-up, or an I
2
C serial interface can be used to
set the desired configurations.
In addition to a crystal input, the UFT features two clock inputs and provides two copies of the
output frequency. Each output is individually programmable as LVPECL or LVDS. Versions of the
UFT with single-ended outputs are also available. Selection between the two input references
may be performed manually via either pin or register, or it may be performed automatically with
revertive or non-revertive recovery.
Part
Number
Output
Frequency
Range
Input
Frequency
Range
OTP
Configs.
Package and
Temp. Range
Output Style
Xtal
Samples
849N202
849N212
840N202
1 MHz to
1300 MHz
1 MHz to
250 MHz
1 MHz to
250 MHz
2x LVDS/LVPECL
1x LVDS/LVPECL
1x LVCMOS
2x LVCMOS
Fundamental
8 kHz to
710 MHz
2
40 QFN,
-40 to +85˚C
Available
IDT
|
THE ANALOG + DIGITAL COMPANY
FEMTOCLOCK UFT PRODUCT BRIEF
1
FemtoClock
®
NG Universal Frequency Translators
POWER MANAGEMENT | ANALOG & RF | INTERFACE & CONNECTIVITY |
CLOCKS & TIMING
| MEMORY & LOGIC | TOUCH & USER INTERFACE | VIDEO & DISPLAY | AUDIO
Integrated DeviceTechnology
STATUS MONITORING
The UFT monitors a number of conditions and
reports their status via both output pins and
register bits, such as:
•
Lock indicator: this status is asserted when
the PLL is locked to the appropriate input
reference for the chosen mode of operation
•
Holdover: indicates that the device is
not locked to a valid input reference clock
FREQUENCY SYNTHESIZER MODE
• Uses a 16 MHz to 40 MHz fundamental mode crystal
• Output frequency range: from 1 MHz to 1300 MHz
• Any frequency output
• Very low RMS jitter
HIGH-BANDWIDTH FREQUENCY
TRANSLATOR MODE
• Input frequency range: from 16 MHz to 710 MHz
• Output frequency range: from 1 MHz to 1300 MHz
• Any frequency output
• Internally selectable bandwidth
• Fast lock time and quick response to
frequency changes
• Allows tracking of Spread-Spectrum clocks
LOW-BANDWIDTH FREQUENCY
TRANSLATOR MODE
• Input frequency range: from 8 kHz to 710 MHz
• Output frequency range: from 1 MHz to 1300 MHz
• Any frequency output
• Internally selectable bandwidth
• External loop filter may be used
Frequency Synthesizer Mode
Frequency Synthesizer Mode allows an arbitrary output frequency to be generated from a
fundamental mode crystal input. The PLL feedback loop supports a second-order delta-sigma
fractional feedback divider. This allows the VCO operating frequency to be a non-integer mul-
tiple of the crystal frequency.
High-Bandwidth Frequency Translator Mode
High-Bandwidth Frequency Translator Mode is used to translate one or two input clocks of
the same nominal frequency into a specified output frequency, attenuating cycle-to-cycle
jitter. As seen on Fig. 1, only the High-Bandwidth PLL loop is used. A pre-divider stage is avail-
able, enabling input frequencies up to 710 MHz.
PD
+
LF
FemtoClock NG
®
VCO
Output
Divider
Q0
nQ0
OE0
Q1
nQ1
OE1
Fractional Feedback Divider
CLK_
SEL
CLK0
nCLK0
CLK1
nCLK1
Switchover
+ Holdover
Logic
Prescaler
One-Time
Programmable
Memory
Registers
CLK_ACTIVE
LOCK_IND
CLK0BAD
CLK1BAD
HOLDOVER
Fig.1: High-Bandwidth Frequency Translator Mode
I
2
C Interface
Low-Bandwidth Frequency Translator Mode (Jitter Attenuator Mode)
Low-Bandwidth Frequency Translator Mode involves two PLL loops and is typically used
to achieve large output-to-input frequency translation ratios. The Low-Bandwidth PLL loop
drives a digitally controlled crystal oscillator (DCXO) loop via an analog-to-digital converter.
The phase detector is optimized to work with frequencies starting at 8 kHz. An external low-
pass filter can be used, as shown on Fig. 2.
Q0
nQ0
OE0
Q1
nQ1
OE1
OSC
PD
+
LF
FemtoClock NG
®
VCO
Output
Divider
Fractional Feedback Divider
CLK_
SEL
CLK0
nCLK0
CLK1
nCLK1
Switchover
+ Holdover
Logic
One-Time
Programmable
Memory
ADC
Divider
Prescaler
Registers
PD
+
CP
Loop Filter
CLK_ACTIVE
LOCK_IND
XTALBAD
CLK0BAD
CLK1BAD
HOLDOVER
Discover what IDT know-how
can do for you:
www.IDT.com
I
2
C Interface
Fig.2: Low -Bandwidth Frequency Translator Mode
DISCLAIMER Integrated Device Technology, Inc. (IDT) and its subsidiaries reserve the right to modify the products and/or specifications described herein at any time and at IDT’s sole discretion. All information in this document, including descriptions of product features and performance, is subject to change without notice. Performance specifications and the operating parameters
of the described products are determined in the independent state and are not guaranteed to perform the same way when installed in customer products. The information contained herein is provided without representation or warranty of any kind, whether express or implied, including, but not limited to, the suitability of IDT’s products for any particular purpose, an implied
warranty of merchantability, or non-infringement of the intellectual property rights of others. This document is presented only as a guide and does not convey any license under intellectual property rights of IDT or any third parties. IDT’s products are not intended for use in life support systems or similar devices where the failure or malfunction of an IDT product can be reasonably
expected to significantly affect the health or safety of users. Anyone using an IDT product in such a manner does so at their own risk, absent an express, written agreement by IDT.
Integrated Device Technology, IDT and the IDT logo are registered trademarks of IDT. Other trademarks and service marks used herein, including protected names, logos and designs, are the property of IDT or their respective third party owners. © Copyright 2011. All rights reserved.
PB_FEMTOCLOCK_UFT_REVB0811
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THE ANALOG + DIGITAL COMPANY
FEMTOCLOCK UFT PRODUCT BRIEF
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