CY2X0137
High Performance LVDS Oscillator
High Performance LVDS Oscillator
Features
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Functional Description
The CY2X0137 is a high-performance and high-frequency XO.
The device uses a Cypress proprietary low-noise PLL to
synthesize the frequency from an integrated crystal.
The CY2X0137 is available as a factory-configured device or as
a field-programmable device. Factory-configured devices are
configured for general use or they can be customer-specific. The
same CY2X0137 can be configured as four different device type
as mentioned in Logic Block Diagram.
For a complete list of related documentation,
click here.
Low jitter crystal oscillator (XO)
Less than 1 ps typical root mean square (RMS) phase jitter
Low-voltage differential signaling (LVDS) output
Output frequency from 50 MHz to 690 MHz
Factory-configured or field-programmable
Integrated phase-locked loop (PLL)
Can be configured as four different type devices
Supply voltage: 3.3 V or 2.5 V
Pb-free package: 7.0 × 5.0 mm leadless chip carrier (LCC)
Commercial and industrial temperature ranges
Cypress Semiconductor Corporation
Document Number: 001-86061 Rev. *B
•
198 Champion Court
•
San Jose
,
CA 95134-1709
•
408-943-2600
Revised December 10, 2014
CY2X0137
Logic Block Diagram
4
CRYSTAL
OSCILLATOR
LOW- NOISE
PLL
CLK
OUTPUT
DIVIDER
5
CLK#
Device Type 1: High Performance
LVDS Crystal Oscillator with Output
Enable
PROGRAMMABLE
CONFIGURATION
1
OE/PD#
6
V
DD
3
V
SS
4
Device Type 2: High Performance
LVDS Crystal Oscillator with
Frequency Margining - I2C control
1
SDA
2
SCL
CRYSTAL
OSCILLATOR
LOW-NOISE
PLL
CLK
OUTPUT
DIVIDER
5
CLK#
PROGRAMMABLE
CONFIGURATION
I
2
C
INTERFACE
4
CLK
Device Type 3: High
Performance LVDS Crystal
Oscillator with Frequency
Margining - Frequency Select
Crystal
Oscillator
Low-Noise PLL
Output
Divider
5
CLK#
FS1
FS0
1
Frequency Select
Decode
2
CRYSTAL
OSC ILLATOR
LOW-NOISE
PLL
OUTPUT
DIVIDER
4
C LK
Device Type 4: High
Performance LVDS Voltage
Controlled Crystal Oscillator
VIN
1
5
PROGRAMMABLE
CONFIGURATION
C LK#
OE/PD#
2
6
VDD
3
VSS
Document Number: 001-86061 Rev. *B
Page 2 of 20
CY2X0137
Contents
Pinouts .............................................................................. 4
Pin Definitions .................................................................. 4
Functional Description ..................................................... 5
Device Type 1 ............................................................. 5
Device Type 2 ............................................................. 5
Device Type 3 ............................................................. 5
Device Type 4 ............................................................. 5
Programming Description ............................................... 6
Field Programmable CY2X0137F ............................... 6
Factory Configured CY2X0137 ................................... 6
Programming Variables ................................................... 6
Output Frequency ........................................................ 6
Pin 1: Output Enable (OE) or Power-Down (PD#) ...... 6
Industrial versus Commercial Device Performance .... 6
Absolute Pull Range .................................................... 6
Memory Map ...................................................................... 7
Serial Interface Protocol and Timing ........................... 7
Device Address ........................................................... 7
Data Valid .................................................................... 7
Data Frame ................................................................. 7
Acknowledge Pulse ..................................................... 7
Write Operations ............................................................... 8
Writing Individual Bytes ............................................... 8
Writing Multiple Bytes .................................................. 8
Read Operations ............................................................... 8
Current Address Read ................................................. 8
Random Read ............................................................. 8
Sequential Read .......................................................... 8
Absolute Maximum Conditions ..................................... 11
Operating Conditions ..................................................... 11
DC Electrical Characteristics ........................................ 12
AC Electrical Characteristics ........................................ 13
Switching Waveforms .................................................... 14
Termination Circuits ....................................................... 15
Ordering Information ...................................................... 16
Possible Configurations ............................................. 16
Ordering Code Definitions ......................................... 16
Package Diagram ............................................................ 17
Acronyms ........................................................................ 18
Document Conventions ................................................. 18
Units of Measure ....................................................... 18
Document History Page ................................................. 19
Sales, Solutions, and Legal Information ...................... 20
Worldwide Sales and Design Support ....................... 20
Products .................................................................... 20
PSoC® Solutions ...................................................... 20
Cypress Developer Community ................................. 20
Technical Support ..................................................... 20
Document Number: 001-86061 Rev. *B
Page 3 of 20
CY2X0137
Pinouts
Figure 1. 6-pin Ceramic LCC pinout
Device Type 1: High
Performance LVDS Crystal
Oscillator with Output
Enable:
Device Type 2: High
Performance LVDS Crystal
Oscillator with Frequency
Margining - I2C control
Device Type 3: High
Performance LVDS Crystal
Oscillator with Frequency
Margining - Frequency
Select
FS1 1
FS0 2
VSS 3
6 VDD
5 CLK#
4 CLK
Device Type 4: High
Performance LVDS Voltage
Controlled Crystal
Oscillator
VIN 1
OE/PD# 2
VSS 3
6 VDD
5 CLK#
4 CLK
OE/PD# 1
DNU 2
V
SS
3
6 V
DD
5 CLK#
4 CLK
SDA 1
SCLK 2
V
SS
3
6 V
DD
5 CLK#
4 CLK
Pin Definitions
6-pin Ceramic LCC
Name
OE/PD#
Device Type 1
1
Device Type 2
N/A
Device Type 3
N/A
Device Type 4
2
I/O Type
CMOS
input
Description
Output enable pin: Active HIGH. If
OE = 1, CLK is enabled.
Power-down pin: Active LOW. If
PD# = 0, the device is powered
down and the clock is disabled. The
functionality
of
this
pin
is
programmable
Differential output clock
Do not use: DNU pins are electrically
connected, but perform no function
Supply voltage: 2.5 V or 3.3 V
Ground
Frequency Select
I2C Serial Data
I2C Serial Clock
VCXO Control voltage, Positive
Slope
CLK,
CLK#
DNU
V
DD
V
SS
FS1, FS0
SDA
SCLK
VIN
4,5
2
6
3
N/A
N/A
N/A
N/A
4,5
N/A
6
3
N/A
1
2
N/A
4,5
N/A
6
3
1,2
N/A
N/A
N/A
4,5
N/A
6
3
N/A
N/A
N/A
1
LVDS
output
–
Power
Power
CMOS
input
I/O
CMOS
input
Analog
input
Document Number: 001-86061 Rev. *B
Page 4 of 20
CY2X0137
Functional Description
Device Type 1
Device Type 1 is a simple Crystal oscillator with one output
frequency. Pin 1 can be programmed either as OE or PD#. The
OE function is used to enable or disable the CLK output whereas
PD# function puts the device into a low-power state,
Figure 2
shows how the frequency words are arranged and
selected.
Figure 2. Frequency Words
Register
Address
10h – 15h
16h – 1Bh
1Ch – 21h
Frequency Word 0
Frequency Word 1
Frequency Word 2
Frequency Word 3
Select Byte
Bits [1:0]
00
01
10
11
Sel
Control
Device Type 2
In Device Type 2, It has an I
2
C bus serial interface
used to change the output frequency.
[1]
,
PLL
which is
22h – 27h
40h
The CY2X0137 comes configured for four different frequencies.
At power-on, the four configurations are transparently loaded
into an internal volatile memory which, in turn, controls the PLL.
The user can switch between the four frequencies through the
I
2
C bus. The user can also configure the CY2X0137 with new
output frequencies by shifting new data into the internal memory.
Frequency margining is a common application for this feature.
One frequency is used for the standard operating mode of the
device, while additional frequencies are available for margin
testing, either during product development or in-system
manufacturing test.
Note that all configuration changes made using I C are
temporary and are lost when power is removed from the device.
At power-on, the device returns to its original state.
The configuration for a particular frequency is stored in a 6-byte
block of memory, known as a word. The CY2X0137 has four
such words, labeled ‘Frequency Word 0’ through ‘Frequency
Word 3’. An additional register byte contains a 2-bit field, which
selects one of the four frequency words. By writing to this select
byte, the user can switch back and forth between the four
programmed frequencies. The select byte can be configured to
select any of the four frequency words at power-on.
When changing the output frequency, the frequency transition is
not guaranteed to be smooth. There can be frequency
excursions beyond the start frequency and the new frequency
Glitches and runt pulses are possible, and time must be allowed
for the PLL to re-lock.
If more than four frequencies are needed, the I
2
C bus can be
used to change any of the four frequency words. When writing
frequency words through I
2
C, the users should not change the
currently selected word. Instead, write one of the three
unselected words before changing the select byte to select that
new word.
2
Device Type 3
The FS0 and FS1 pins select between four different output
frequencies, as shown in
Table 1.
Frequency margining is a
common application for this feature. One frequency is used for
the standard operating mode of the device, while the other
frequencies are available for margin testing, either during
product development or in system manufacturing test.
Table 1. Frequency Select
FS1
0
0
1
1
FS0
0
1
0
1
Output Frequency
Frequency 0
Frequency 1
Frequency 2
Frequency 3
When changing the output frequency, the frequency transition is
not guaranteed to be smooth. There can be frequency
excursions beyond the start frequency and the new frequency.
Glitches and runt pulses are possible, and time must be allowed
for the PLL to relock.
Device Type 4
Device Type 4 is a Voltage Controlled Crystal Oscillator. It has a
Control voltage pin VIN which is an analog input that is used to
adjust the output frequency. The nominal output frequency is
defined when VIN = V
DD,NOM
/2. Increasing the voltage on VIN
increases the output frequency, while decreasing the voltage on
VIN decreases the output frequency. Any voltage between V
SS
and V
DD
is allowed on VIN. The voltage or frequency slope is
very linear over most of the control voltage range.
Note
1. The serial interface is I
2
C Bus compliant, with the following exceptions: SDA input leakage current, SDA input capacitance, SDA and SCLK are clamped to V
DD
,
setup time, and output hold time.
Document Number: 001-86061 Rev. *B
Page 5 of 20
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