THIS SPEC IS OBSOLETE
Spec No:
001-59931
Spec Title:
CY2XP311, 312.5 MHZ LVPECL CLOCK GENERATOR
Replaced by:
None
CY2XP311
312.5 MHz LVPECL Clock Generator
312.5 MHz LVPECL Clock Generator
Features
Functional Description
■
One LVPECL output pair
■
Output frequency: 312.5 MHz
■
External crystal frequency: 25 MHz
■
Low RMS phase jitter at 312.5 MHz, using 25-MHz crystal
(1.875 MHz to 20 MHz): 0.3 ps (typical)
■
Pb-free 8-pin TSSOP package
■
Supply voltage: 3.3 V or 2.5 V
■
Commercial and industrial temperature ranges
The CY2XP311 is a PLL (phase locked loop) based high
performance clock generator. It is optimized to generate 10 GB
Ethernet, SONET, and other high performance clock
frequencies. It also produces an output frequency that is 12.5
times the crystal frequency. It uses Cypress’s low noise VCO
technology to achieve 0.3 ps typical RMS phase jitter, which
meets both 10 GB Ethernet and SONET jitter requirements. The
CY2XP311 has a crystal oscillator interface input and one
LVPECL output pair.
For a complete list of related documentation, click here.
Logic Block Diagram
XIN
External
Crystal
CRYSTAL
OSCILLATOR
PHASE
DETECTOR
VCO
/2
CLK
CLK#
XOUT
/25
OE
Cypress Semiconductor Corporation
Document Number: 001-59931 Rev. *F
•
198 Champion Court
•
San Jose, CA 95134-1709
•
408-943-2600
Revised April 27, 2020
CY2XP311
Contents
Pinouts .............................................................................. 3
Pin Definitions .................................................................. 3
Frequency Table ............................................................... 3
Absolute Maximum Conditions ....................................... 4
Operating Conditions ....................................................... 4
DC Electrical Characteristics .......................................... 5
AC Electrical Characteristics .......................................... 6
Recommended Crystal Specifications ........................... 6
Parameter Measurements ................................................ 7
Application Information ................................................... 9
Power Supply Filtering Techniques ............................. 9
Termination for LVPECL Output .................................. 9
Crystal Input Interface ................................................. 9
Document Number: 001-59931 Rev. *F
Ordering Information ...................................................... 10
Ordering Code Definitions ......................................... 10
Package Drawing and Dimensions ............................... 11
Acronyms ........................................................................ 12
Document Conventions ................................................. 12
Units of Measure ....................................................... 12
Document History Page ................................................. 13
Sales, Solutions, and Legal Information ...................... 14
Worldwide Sales and Design Support ....................... 14
Products .................................................................... 14
PSoC® Solutions ...................................................... 14
Cypress Developer Community ................................. 14
Technical Support ..................................................... 14
Page 2 of 14
CY2XP311
Pinouts
Figure 1. 8-pin TSSOP pinout
VDD
VSS
XOUT
XIN
1
2
3
4
8
7
6
5
VDD
CLK
CLK#
OE
Pin Definitions
8-pin TSSOP
Pin Number
Pin Name
I/O Type
Description
1, 8
VDD
Power
3.3 V or 2.5 V power supply.
2
VSS
Power
Ground
3, 4
XOUT, XIN
5
OE
CMOS input
6, 7
CLK#, CLK
LVPECL output
XTAL output and input Parallel resonant crystal interface
Output enable. When HIGH, the output is enabled. When LOW, the output is
high impedance
Differential clock output
Frequency Table
Input
Crystal Frequency (MHz)
PLL Multiplier Value
25
12.5
Document Number: 001-59931 Rev. *F
Output Frequency (MHz)
312.5
Page 3 of 14
CY2XP311
Absolute Maximum Conditions
Parameter
Description
Conditions
Min
Max
Unit
–
–0.5
4.4
V
VDD
Supply voltage
VIN[1]
Input voltage, DC
Relative to VSS
–0.5
VDD + 0.5
V
TS
Temperature, storage
Non operating
–65
150
C
TJ
Temperature, junction
–
–
135
C
ESDHBM
ESD protection, human body
model
JEDEC STD 22-A114-B
2000
–
V
UL–94
Flammability rating
At 1/8 in.
V–0
JA[2]
Thermal resistance, junction to
ambient
0 m/s airflow
100
1 m/s airflow
91
2.5 m/s airflow
87
C/W
Operating Conditions
Parameter
VDD
TA
TPU
Description
Min
Max
Unit
3.3 V supply voltage
3.135
3.465
V
2.5 V supply voltage
2.375
2.625
V
0
70
C
Ambient temperature, industrial
–40
85
C
Power up time for all VDD to reach minimum specified voltage (ensure power ramps
is monotonic)
0.05
500
ms
Ambient temperature, commercial
Notes
1. The voltage on any input or I/O pin cannot exceed the power pin during power up.
2. Simulated using Apache Sentinel TI software. The board is derived from the JEDEC multilayer standard. It measures 76 x 114 x 1.6 mm and has 4-layers of copper
(2/1/1/2 oz.). The internal layers are 100% copper planes, while the top and bottom layers have 50% metalization. No vias are included in the model.
Document Number: 001-59931 Rev. *F
Page 4 of 14
CY2XP311
DC Electrical Characteristics
Parameter
IDD
Description
Operating supply current with
output unterminated
IDDT
Operating supply current with
output terminated
Test Conditions
Min
Typ
Max
Unit
VDD = 3.465 V, OE = VDD,
output unterminated
–
–
125
mA
VDD = 2.625 V, OE = VDD,
output unterminated
–
–
120
mA
VDD = 3.465 V, OE = VDD,
output terminated
–
–
150
mA
VDD = 2.625 V, OE = VDD,
output terminated
–
–
145
mA
VOH
LVPECL output high voltage
VDD = 3.3 V or 2.5 V,
RTERM = 50 to VDD – 2.0 V
VDD – 1.15
–
VDD – 0.75
V
VOL
LVPECL output low voltage
VDD = 3.3 V or 2.5 V,
RTERM = 50 to VDD – 2.0 V
VDD – 2.0
–
VDD – 1.625
V
VOD1
LVPECL peak-to-peak output
voltage swing
VDD = 3.3 V or 2.5 V,
RTERM = 50 to VDD – 2.0 V
600
–
1000
mV
VOD2
LVPECL output voltage swing
(VOH – VOL)
VDD = 2.5 V,
RTERM = 50 to VDD – 1.5 V
500
–
1000
mV
VOCM
LVPECL output common mode
voltage (VOH + VOL)/2
VDD = 2.5 V,
RTERM = 50 to VDD – 1.5 V
1.2
–
–
V
IOZ
LVPECL output leakage current
Output off, OE = VSS
–35
–
35
A
VIH
Input high voltage, OE Pin
–
0.7 × VDD
–
VDD + 0.3
V
VIL
Input low voltage, OE Pin
–
–0.3
–
0.3 × VDD
V
IIH
Input high current, OE Pin
OE = VDD
–
–
115
µA
Input low current, OE Pin
OE = VSS
–50
–
–
µA
Input capacitance, OE Pin
–
–
15
–
pF
Pin capacitance, XIN & XOUT
–
–
4.5
–
pF
IIL
CIN
[3]
CINX[3]
Notes
3. Not 100% tested, guaranteed by design and characterization.
Document Number: 001-59931 Rev. *F
Page 5 of 14
CY2XP311
AC Electrical Characteristics
Parameter [4]
FOUT
TR, TF[5]
TJitter()
Description
Conditions
Output frequency
[6]
Min
Typ
Max
Unit
–
312.5
–
MHz
Output rise or fall time
20% to 80% of full output swing
–
0.5
1.0
ns
–
ps
RMS phase jitter (random)
312.5 MHz, (1.875 to 20 MHz)
–
0.3
TDC[7]
Output duty cycle
Measured at zero crossing point
45
–
55
%
TOHZ
Output disable time
Time from falling edge on OE to
stopped outputs (Asynchronous)
–
–
100
ns
TOE
Output enable time
Time from rising edge on OE to
outputs at a valid frequency
(Asynchronous)
–
–
100
ns
TLOCK
Startup time
Time for CLK to reach valid
frequency measured from the time
VDD = VDD(min.)
–
–
5
ms
Min
Max
Unit
Recommended Crystal Specifications
Parameter [8]
Description
Mode
Mode of Oscillation
Fundamental
–
F
Frequency
25
25
ESR
Equivalent Series Resistance
–
50
CS
Shunt Capacitance
–
7
pF
MHz
Notes
4. Not 100% tested, guaranteed by design and characterization.
5. Refer to Figure 5 on page 7.
6. Refer to Figure 6 on page 7.
7. Refer to Figure 7 on page 8.
8. Characterized using an 18 pF parallel resonant crystal.
Document Number: 001-59931 Rev. *F
Page 6 of 14
CY2XP311
Parameter Measurements
Figure 2. 3.3 V Output Load AC Test Circuit
2V
Z = 50
VDD
SCOPE
CLK
50
LVPECL
Z = 50
VSS
CLK#
50
-1.3V +/- 0.165V
Figure 3. 2.5 V Output Load AC Test Circuit
2V
VDD
SCOPE
Z = 50
CLK
Z = 50
CLK#
50
LVPECL
VSS
50
-0.5V +/- 0.125V
Figure 4. Output DC Parameters
VA
CLK
VOD
VOCM = (V A + VB)/2
CLK#
VB
Figure 5. Output Rise and Fall Time
CLK#
CLK
80%
80%
20%
20%
TR
TF
Figure 6. RMS Phase Jitter
Document Number: 001-59931 Rev. *F
Page 7 of 14
CY2XP311
Parameter Measurements (continued)
Phase noise
Noise
Power
Phase noise mask
Offset Frequency
f2
f1
RMS Jitter =
Area Under the Masked Phase Noise Plot
Figure 7. Output Duty Cycle
CLK
TDC =
CLK#
TPW
TPERIOD
TPW
TPERIOD
Figure 8. Output Enable Timing
OE
VIL
TOHZ
VIH
TOE
CLK
High Impedance
CLK#
Document Number: 001-59931 Rev. *F
Page 8 of 14
CY2XP311
Application Information
Power Supply Filtering Techniques
As in any high speed analog circuitry, noise at the power supply
pins can degrade performance. To achieve optimum jitter
performance, use good power supply isolation practices.
Figure 9 illustrates a typical filtering scheme. 0.01 to 0.1 µF
ceramic chip capacitors are located close to the VDD pins to
provide a short and low impedance AC path to ground. A 1 to 10
µF ceramic or tantalum capacitor is located in the general vicinity
of this device and may be shared with other devices. An
acceptable alternative power supply configuration is shown in
Figure 10.
Figure 9. Power Supply Filtering
3.3V or 2.5V
VDD
(Pin 8)
VDD
(Pin 1)
3.3V
125
125
Z0 = 50
CLK
CLK#
IN
Z0 = 50
84
84
Crystal Input Interface
0.01µF
10µF
3.3V or 2.5V
The CY2XP311 is characterized with 18 pF parallel resonant
crystals. The capacitor values shown in Figure 12 are
determined using a 25 MHz 18 pF parallel resonant crystal and
are chosen to minimize the ppm error. Note that the optimal
values for C1 and C2 depend on the parasitic trace capacitance
and are therefore layout dependent.
Figure 12. Crystal Input Interface
XIN
0.01µF
10
VDD
(Pin 1)
Figure 11. LVPECL Output Termination
0.01µF
Figure 10. Alternative Power Supply Filtering
VDD
(Pin 8)
for VDD = 2.5 V operation, or it can be terminated to VDD–1.5 V.
Note that it is also possible to terminate with 50 ohms to ground
(VSS), but the high and low signal levels differ from the data sheet
values. Termination resistors are best located close to the
destination device. To avoid reflections, trace characteristic
impedance (Z0) should match the termination impedance.
Figure 11 shows a standard termination scheme.
0.01µF
10µF
X1
18 pF Parallel
Crystal
C1
33 pF
Device
XOUT
C2
27 pF
Termination for LVPECL Output
The CY2XP311 implements its LVPECL driver with a current
steering design. For proper operation, it requires a 50 ohm dc
termination on each of the two output signals. For 3.3 V
operation, this data sheet specifies output levels for termination
to VDD–2.0 V. This same termination voltage can also be used
Document Number: 001-59931 Rev. *F
Page 9 of 14
CY2XP311
Ordering Information
Part Number
Package Type
Product Flow
CY2XP311ZXI
8-pin TSSOP
Industrial, –40 C to 85 C
CY2XP311ZXIT
8-pin TSSOP – Tape and Reel
Industrial, –40 C to 85 C
Ordering Code Definitions
CY 2X P311 Z X
X
T
X = blank or T
blank = Tube; T = Tape and Reel
Temperature Range: X = C or I
C = Commercial; I = Industrial
Pb-free
Package Type: Z = 8-pin TSSOP
Part Identifier
Family
Company ID: CY = Cypress
Document Number: 001-59931 Rev. *F
Page 10 of 14
CY2XP311
Package Drawing and Dimensions
Figure 13. 8-pin TSSOP (4.40 mm Body) Package Outline, 51-85093
51-85093 *E
Document Number: 001-59931 Rev. *F
Page 11 of 14
CY2XP311
Acronyms
Acronym
Document Conventions
Description
Units of Measure
CLKOUT
Clock Output
CMOS
Complementary Metal Oxide Semiconductor
°C
degree Celsius
DPM
Die Pick Map
kHz
kilohertz
EPROM
Erasable Programmable Read Only Memory
k
kilohm
LVDS
Low-Voltage Differential Signalling
MHz
megahertz
LVPECL
Low-Voltage Positive Emitter Coupled Logic
M
megaohm
NTSC
National Television System Committee
µA
microampere
OE
Output Enable
PAL
Phase Alternate Line
PD
Power Down
PLL
Phase Locked Loop
TTL
Transistor-Transistor Logic
Document Number: 001-59931 Rev. *F
Symbol
Unit of Measure
µs
microsecond
µV
microvolt
µVrms
microvolts root-mean-square
mA
milliampere
mm
millimeter
ms
millisecond
mV
millivolt
nA
nanoampere
ns
nanosecond
nV
nanovolt
ohm
ppm
parts per million
V
volt
Page 12 of 14
CY2XP311
Document History Page
Document Title: CY2XP311, 312.5 MHz LVPECL Clock Generator
Document Number: 001-59931
Rev.
ECN No.
Orig. of
Change
Submission
Date
**
2897143
KVM
03/22/2010
*A
2915328
KVM
04/16/2010
Changed status from Preliminary to Final.
*B
3201150
BASH
03/21/2011
Updated Ordering Information:
No change in part numbers.
Added Ordering Code Definitions.
Updated Package Drawing and Dimensions:
spec 51-85093 – Changed revision from *B to *C.
Added Acronyms and Units of Measure.
*C
4335323
CINM
04/07/2014
Updated Package Drawing and Dimensions:
spec 51-85093 – Changed revision from *C to *D.
Updated to new template.
Completing Sunset Review.
*D
4570097
CINM
11/14/2014
Updated Functional Description:
Added “For a complete list of related documentation, click here.” in the end.
Updated Ordering Information:
Updated part numbers.
Updated Package Drawing and Dimensions:
spec 51-85093 – Changed revision from *D to *E.
*E
5686604
XHT
04/06/2017
Updated to new template.
Completing Sunset Review.
*F
6869116
XHT
04/27/2020
Obsolete document.
Completing Sunset Review.
Document Number: 001-59931 Rev. *F
Description of Change
New data sheet.
Page 13 of 14
CY2XP311
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© Cypress Semiconductor Corporation, 2010-2020. This document is the property of Cypress Semiconductor Corporation and its subsidiaries, including Spansion LLC ("Cypress"). This document,
including any software or firmware included or referenced in this document ("Software"), is owned by Cypress under the intellectual property laws and treaties of the United States and other countries
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Document Number: 001-59931 Rev. *F
Revised April 27, 2020
Page 14 of 14