Product
Folder
Sample &
Buy
Support &
Community
Tools &
Software
Technical
Documents
CDCLVD1213
SCAS897A – JULY 2010 – REVISED OCTOBER 2016
CDCLVD1213 1:4 Low Additive Jitter LVDS Buffer With Divider
1 Features
3 Description
•
•
The CDCLVD1213 clock buffer distributes an input
clock to 4 pairs of differential LVDS clock outputs with
low additive jitter for clock distribution. The input can
either be LVDS, LVPECL, or CML.
1
•
•
•
•
•
•
•
•
•
1:4 Differential Buffer
Low Additive Jitter: < 300-fs RMS in 10-kHz to 20MHz
Low Output Skew of 20 ps (Maximum)
Selectable Divider Ratio 1, /2, /4
Universal Input Accepts LVDS, LVPECL, and
CML
4 LVDS Outputs, ANSI EIA/TIA-644A Standard
Compatible
Clock Frequency: Up to 800 MHz
Device Power Supply: 2.375 V to 2.625 V
Industrial Temperature Range: –40°C to 85°C
Packaged in 3 mm × 3 mm, 16-Pin VQFN (RGT)
ESD Protection Exceeds 3-kV HBM, 1-kV CDM
The CDCLVD1213 contains a high performance
divider for one output (QD) which can divide the input
clock signal by a factor of 1, 2, or 4.
The CDCLVD1213 is specifically designed for driving
50-Ω transmission lines. The part supports a fail-safe
function. The device incorporates an input hysteresis
which prevents random oscillation of the outputs in
the absence of an input signal.
The device operates in 2.5-V supply environment and
is characterized from –40°C to 85°C (ambient
temperature). The CDCLVD1213 is packaged in
small, 16-pin, 3-mm × 3-mm VQFN package.
Device Information(1)
2 Applications
•
•
•
•
•
PART NUMBER
Telecommunications and Networking
Medical Imaging
Test and Measurement Equipment
Wireless Communications
General-Purpose Clocking
CDCLVD1213
PACKAGE
VQFN (16)
BODY SIZE (NOM)
3.00 mm × 3.00 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Application Example
CDCLVD1213 Block Diagram
QP0
QN0
ASIC
INP
156.25 MHz
QP1
INN
QN1
QP2
70 W
70 W
QN2
PHY1
VT
VCC
CDCLVD1213
LVDS Buffer
with Divider
DIV
200 kW
QDP
/1 /2 /4
QDN
DIV
PHY2
200 kW
GND
Copyright © 2016, Texas Instruments Incorporated
FPGA
Copyright © 2016, Texas Instruments Incorporated
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
CDCLVD1213
SCAS897A – JULY 2010 – REVISED OCTOBER 2016
www.ti.com
Table of Contents
1
2
3
4
5
6
7
8
Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
2
3
3
6.1
6.2
6.3
6.4
6.5
6.6
6.7
3
4
4
4
4
5
6
Absolute Maximum Ratings ......................................
ESD Ratings..............................................................
Recommended Operating Conditions.......................
Thermal Information ..................................................
Electrical Characteristics...........................................
Timing Requirements ................................................
Typical Characteristics ..............................................
Parameter Measurement Information .................. 7
Detailed Description .............................................. 9
8.1 Overview ................................................................... 9
8.2 Functional Block Diagram ......................................... 9
8.3 Feature Description................................................... 9
8.4 Device Functional Modes.......................................... 9
9
Application and Implementation ........................ 12
9.1 Application Information............................................ 12
9.2 Typical Application .................................................. 12
10 Power Supply Recommendations ..................... 14
11 Layout................................................................... 15
11.1 Layout Guidelines ................................................. 15
11.2 Layout Example .................................................... 15
11.3 Thermal Considerations ........................................ 15
12 Device and Documentation Support ................. 16
12.1
12.2
12.3
12.4
12.5
12.6
Documentation Support ........................................
Receiving Notification of Documentation Updates
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
16
16
16
16
16
16
13 Mechanical, Packaging, and Orderable
Information ........................................................... 16
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Original (July 2010) to Revision A
•
2
Page
Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation
section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and
Mechanical, Packaging, and Orderable Information section. ................................................................................................. 1
Submit Documentation Feedback
Copyright © 2010–2016, Texas Instruments Incorporated
Product Folder Links: CDCLVD1213
CDCLVD1213
www.ti.com
SCAS897A – JULY 2010 – REVISED OCTOBER 2016
5 Pin Configuration and Functions
QP1
QN0
QP0
VCC
GND
RGT Package
16-Pin VQFN
Top View
12
11
10
9
13
QN1
14
QP2
15
3mm x 3mm
16 pin QFN (RGT)
8
VT
7
INP
6
INN
5
VCC
Thermal Pad
2
3
4
DIV
GND
1
QDN
16
QDP
QN2
Pin Functions
PIN
NO.
NAME
TYPE
DESCRIPTION
1, 9
GND
Ground
Device ground
2, 3
QDP, QDN
Output
Differential divided LVDS output pair
4
DIV
Input with an
internal 200-kΩ
pullup and
pulldown
5, 10
VCC
Power
6, 7
INN, INP
Input
Differential input pair
VT
Input
Input for threshold voltage
11, 12
QP0, QN0
Output
Differential LVDS output pair number 0
13, 14
QP1, QN1
Output
Differential LVDS output pair number 1
QP2, QN2
Output
Differential LVDS output pair number 2
Thermal Pad
—
8
15, 16
—
Divider selection – selects divider ratio for QD output (see Table 1).
2.5-V supply for the device
See thermal management recommendations
6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1)
MIN
MAX
UNIT
Supply voltage, VCC
–0.3
2.8
V
Input voltage, VI
–0.2
VCC + 0.2
V
Output voltage, VO
–0.2
VCC + 0.2
V
150
°C
See Note (2)
Driver short-circuit current , IOSD
Storage temperature, Tstg
(1)
(2)
–65
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
The output can handle the permanent short.
Submit Documentation Feedback
Copyright © 2010–2016, Texas Instruments Incorporated
Product Folder Links: CDCLVD1213
3
CDCLVD1213
SCAS897A – JULY 2010 – REVISED OCTOBER 2016
www.ti.com
6.2 ESD Ratings
VALUE
V(ESD)
(1)
(2)
Electrostatic discharge
Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1)
>3000
Charged-device model (CDM), per JEDEC specification JESD22-C101 (2)
>1000
UNIT
V
Human-body model, 1.5-kΩ, 100-pF
JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
VCC
Device supply voltage
TA
Ambient temperature
MIN
NOM
MAX
2.375
2.5
2.625
V
85
°C
–40
UNIT
6.4 Thermal Information
CDCLVD1213
THERMAL METRIC (1)
RGT (VQFN)
UNIT
16 PINS
RθJA
Junction-to-ambient thermal resistance
51.3
°C/W
RθJC(top)
Junction-to-case (top) thermal resistance
85.4
°C/W
RθJB
Junction-to-board thermal resistance
20.1
°C/W
ψJT
Junction-to-top characterization parameter
1.3
°C/W
ψJB
Junction-to-board characterization parameter
19.4
°C/W
RθJC(bot)
Junction-to-case (bottom) thermal resistance
6
°C/W
(1)
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report.
6.5 Electrical Characteristics
VCC = 2.375 V to 2.625 V and TA = –40°C to 85°C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
DIVIDER CONTROL INPUT (DIV) CHARACTERISTICS
VdI3
3-state input
VdIH
Input high voltage
Open
VdIL
Input low voltage
IdIH
Input high current
VCC = 2.625 V, VIH = 2.625 V
IdIL
Input low current
VCC = 2.625 V, VIL = 0 V
Rpull(DIV)
Input pullup or pulldown resistor
0.5 × VCC
V
0.7 × VCC
V
0.2 × VCC
V
30
μA
–30
200
μA
kΩ
DIFFERENTIAL INPUTS (INP, INN) CHARACTERISTICS
fIN
Input frequency
Clock input
VIN,
Differential input voltage peak-topeak
VICM = 1.25 V
DIFF
VICM
Input common-mode voltage range
RIN
Input termination
INP, INN to VT, DC
IIH
Input high current
VCC = 2.625 V, VIH = 2.625 V
IIL
Input low current
VCC = 2.625 V, VIL = 0 V
ΔV/ΔT
Input edge rate
20% to 80%
CIN
Input capacitance
4
0.3
1
MHz
1.6
VPP
VCC – 0.3
70
–10
0.75
V
Ω
10
μA
μA
V/ns
2.5
Submit Documentation Feedback
800
pF
Copyright © 2010–2016, Texas Instruments Incorporated
Product Folder Links: CDCLVD1213
CDCLVD1213
www.ti.com
SCAS897A – JULY 2010 – REVISED OCTOBER 2016
Electrical Characteristics (continued)
VCC = 2.375 V to 2.625 V and TA = –40°C to 85°C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
250
450
mV
–15
15
mV
1.1
1.375
–15
15
LVDS OUTPUT CHARACTERISTICS
|VOD|
Differential output voltage magnitude
ΔVOD
Change in differential output voltage
magnitude
VOC(SS)
Steady-state common-mode output
voltage
ΔVOC(SS)
Steady-state common-mode output
voltage
VIN, DIFF, PP = 0.6 V,
RL = 100 Ω
IOS
Short-circuit output current
VOD = 0 V
VOS
Output AC common mode
VIN, DIFF, PP = 0.6 V, RL = 100 Ω
Vring
Output overshoot and undershoot
Percentage of output amplitude
VOD
tPD
Propagation delay
VIN, DIFF, PP = 0.3 V
tSK, PP
Part-to-part skew
VIN, DIFF, PP = 0.3 V,
RL = 100 Ω
25
V
mV
±24
mA
70
mVPP
10%
1.5
(1)
2.5
ns
600
ps
20
ps
50
ps
tSK, O
Output skew
tSK,P
Pulse skew (with 50% duty cycle
input)
Crossing-point-to-crossing-point
distortion
tRJIT
Random additive jitter (with 50% duty
cycle input)
Edge speed 0.75 V/ns
10 kHz – 20 MHz
tR/tF
Output rise/fall time
20% to 80%,100 Ω, 5 pF
300
ps
ICCSTAT
Static supply current
Outputs unterminated, f = 0 Hz
17
28
mA
ICC100
Supply current
All outputs, RL = 100 Ω,
f = 100 MHz
40
58
mA
ICC800
Supply current
All outputs, RL = 100 Ω,
f = 800 MHz
60
85
mA
(1)
–50
0.3 ps, RMS
50
Undivided outputs only.
6.6 Timing Requirements
MIN
NOM
MAX
UNIT
ADDITIVE PHASE NOISE FOR 100-MHZ CLOCK
phn100
Phase noise at 100-Hz offset
–132.9
dBc/Hz
phn1k
Phase noise at 1-kHz offset
–138.8
dBc/Hz
phn10k
Phase noise at 10-kHz offset
–147.4
dBc/Hz
phn100k
Phase noise at 100-kHz offset
–153.6
dBc/Hz
phn1M
Phase noise at 1-MHz offset
–155.2
dBc/Hz
phn10M
Phase noise at 10-MHz offset
–156.2
dBc/Hz
phn20M
Phase noise at 20-MHz offset
–156.6
dBc/Hz
tRJIT
Random additive jitter from 10 kHz to 20 MHz
171
fs, RMS
ADDITIVE PHASE NOISE FOR 737.27-MHZ CLOCK
phn100
Phase noise at 100-Hz offset
phn1k
Phase noise at 1-kHz offset
–80.2
dBc/Hz
–114.3
phn10k
Phase noise at 10-kHz offset
dBc/Hz
–138
dBc/Hz
phn100k
phn1M
Phase noise at 100-kHz offset
–143.9
dBc/Hz
Phase noise at 1-MHz offset
–145.2
dBc/Hz
phn10M
Phase noise at 10-MHz offset
–146.5
dBc/Hz
phn20M
Phase noise at 20-MHz offset
–146.6
dBc/Hz
tRJIT
Random additive jitter from 10 kHz to 20 MHz
65
fs, RMS
Submit Documentation Feedback
Copyright © 2010–2016, Texas Instruments Incorporated
Product Folder Links: CDCLVD1213
5
CDCLVD1213
SCAS897A – JULY 2010 – REVISED OCTOBER 2016
www.ti.com
6.7 Typical Characteristics
VOD − Differential Output Voltage − mV
350
TA = 25oC
340
2.625V
330
320
2.5V
310
300
2.375V
290
280
270
260
250
0
100
200
300
400
500
600
700
800
Frequency − MHz
Input clock RMS jitter is 32 fs from 10 kHz to 20 MHz and additive
RMS jitter is 152 fs, TA = 25°C, and VCC = 2.5 V
Figure 1. 100-MHz Input and Output Phase Noise Plot
6
Figure 2. Differential Output Voltage vs Frequency
Submit Documentation Feedback
Copyright © 2010–2016, Texas Instruments Incorporated
Product Folder Links: CDCLVD1213
CDCLVD1213
www.ti.com
SCAS897A – JULY 2010 – REVISED OCTOBER 2016
7 Parameter Measurement Information
Oscilloscope
100 W
LVDS
Figure 3. LVDS Output DC Configuration During Device Test
Phase Noise
Analyzer
LVDS
50 W
Figure 4. LVDS Output AC Configuration During Device Test
VOH
OUTNx
VOD
OUTPx
VOL
80%
VOUT,DIFF,PP (= 2 x VOD)
20%
0V
tR
tF
Figure 5. Output Voltage and Rise/Fall Time
INN
INP
tPLH0
tPHL0
tPLH1
tPHL1
QN0
QP0
QN1
QP1
tPLH2
tPHL2
QN2
QP2
(1)
Output skew is calculated as the greater of the following: As the difference between the fastest and the slowest tPLHn
or the difference between the fastest and the slowest tPHLn (n = 0, 1, 2).
(2)
Part-to-part skew is calculated as the greater of the following: As the difference between the fastest and the slowest
tPLHn or the difference between the fastest and the slowest tPHLn across multiple devices (n = 0, 1, 2).
Figure 6. Output and Part-to-Part Skew
Submit Documentation Feedback
Copyright © 2010–2016, Texas Instruments Incorporated
Product Folder Links: CDCLVD1213
7
CDCLVD1213
SCAS897A – JULY 2010 – REVISED OCTOBER 2016
www.ti.com
Parameter Measurement Information (continued)
Vring
QNx
VOD
0V Differential
QPx
Figure 7. Output Overshoot and Undershoot
VOS
GND
Figure 8. Output AC Common Mode
8
Submit Documentation Feedback
Copyright © 2010–2016, Texas Instruments Incorporated
Product Folder Links: CDCLVD1213
CDCLVD1213
www.ti.com
SCAS897A – JULY 2010 – REVISED OCTOBER 2016
8 Detailed Description
8.1 Overview
The CDCLVD1213 LVDS drivers use CMOS transistors to control the output current. Therefore, proper biasing
and termination are required to ensure correct operation of the device and to maximize signal integrity.
The proper LVDS termination for signal integrity over two 50-Ω lines is 100 Ω between the outputs on the
receiver end. Either DC-coupled termination or AC-coupled termination can be used for LVDS outputs. TI
recommends placing a termination resistor close to the receiver. If the receiver is internally biased to a voltage
different than the output common-mode voltage of the CDCLVD1213, AC-coupling must be used. If the LVDS
receiver has internal 100-Ω termination, external termination must be omitted.
8.2 Functional Block Diagram
QP0
QN0
INP
QP1
INN
QN1
QP2
70 W
70 W
QN2
VT
VCC
QDP
/1 /2 /4
200 kW
QDN
DIV
200 kW
GND
Copyright © 2016, Texas Instruments Incorporated
8.3 Feature Description
The CDCLVD1213 is a low additive jitter LVDS fan-out buffer that can generate four copies of an LVPECL,
LVDS, or CML input, one of which can be frequency divided by a factor of 1, 2, or 4. The CDCLVD1213 can
accept reference clock frequencies up to 800 MHz while providing low output skew.
8.4 Device Functional Modes
The divider on output QD can be configured to divide the input frequency by a factor 1, 2, or 4 through the
control pin (see Table 1). Unused outputs can be left floating to reduce overall component cost. Both AC- and
DC-coupling schemes can be used with the CDCLVD1213 to provide greater system flexibility.
Table 1. Divider Selection Table
DIV
DIVIDER RATIO
0
/1
open
/2
1
/4
Submit Documentation Feedback
Copyright © 2010–2016, Texas Instruments Incorporated
Product Folder Links: CDCLVD1213
9
CDCLVD1213
SCAS897A – JULY 2010 – REVISED OCTOBER 2016
www.ti.com
8.4.1 LVDS Output Termination
Unused outputs can be left open without connecting any traces to the output pins.
The CDCLVD1213 can be connected to LVDS receiver inputs with DC- and AC-coupling as shown in Figure 9
and Figure 10 (respectively).
Z = 50 W
100 W
CDCLVD1213
LVDS
Z = 50 W
Figure 9. Output DC Termination
100 nF
Z = 50 W
100 W
CDCLVD1213
LVDS
Z = 50 W
100 nF
Figure 10. Output AC Termination (With the Receiver Internally Biased)
8.4.2 Input Termination
The CDCLVD1213 input has an internal 140-Ω termination and can be interfaced with LVDS, LVPECL, or CML
drivers. An external 350-Ω resistor (in parallel with the internal 140-Ω termination) is required to interface with a
50-Ω transmission line.
LVDS drivers can be connected to CDCLVD1213 inputs with DC- and AC-coupling as shown in Figure 11 and
Figure 12 (respectively). With AC coupling, an external bias voltage (VCC/2) must be provided to the VT pin.
Z = 50 W
350 W
LVDS
CDCLVD1213
Z = 50 W
Figure 11. LVDS Clock Driver Connected to CDCLVD1213 Input (DC-Coupled)
100 nF
Z = 50 W
350 W
LVDS
CDCLVD1213
Z = 50 W
100 nF
VT = 1.25V
Figure 12. LVDS Clock Driver Connected to CDCLVD1213 Input (AC-Coupled)
Figure 13 illustrates how to connect a CML input to the CDCLVD1213 input buffer. The input does not have
internal biasing, so external biasing (VCC/2 to VT) is required for AC coupling. If the CML output swing is >1.6
VPP, then signal swing must be reduced to meet VIN, DIF, PP ≤ 1.6 VPP.
10
Submit Documentation Feedback
Copyright © 2010–2016, Texas Instruments Incorporated
Product Folder Links: CDCLVD1213
CDCLVD1213
www.ti.com
SCAS897A – JULY 2010 – REVISED OCTOBER 2016
100 nF
Z = 50 W
350 W
CML
CDCLVD1213
Z = 50 W
100 nF
VT = 1.25V
Figure 13. CML Clock Driver Connected to CDCLVD1213 Input
Figure 14 illustrates how to connect an LVPECL input to the CDCLVD1213 input buffer. The input does not have
internal biasing, so external biasing (VCC/2 to VT) is required for AC coupling. The series resistors are required to
reduce the LVPECL signal swing if the signal swing is >1.6 Vpp.
75 W
100 nF
Z = 50 W
350 W
LVPECL
CDCLVD1213
Z = 50 W
75 W
150 W
150 W
100 nF
VT = 1.25V
Figure 14. LVPECL Clock Driver Connected to CDCLVD1213 Input
Submit Documentation Feedback
Copyright © 2010–2016, Texas Instruments Incorporated
Product Folder Links: CDCLVD1213
11
CDCLVD1213
SCAS897A – JULY 2010 – REVISED OCTOBER 2016
www.ti.com
9 Application and Implementation
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
9.1 Application Information
The CDCLVD1213 is a low additive jitter universal to LVDS fan-out buffer with an integrated frequency divider on
one output. The small package, low output skew, and low additive jitter make for a flexible device in demanding
applications.
9.2 Typical Application
2.5 V
PHY
INP
156.25 MHz LVDS
From Backplane
100
350
INN
2.5 V
1k
ASIC
VT
100
1k
FPGA
DIV
100
100
CPU
100
Copyright © 2016, Texas Instruments Incorporated
Figure 15. Fan-Out Buffer for Line Card Application
12
Submit Documentation Feedback
Copyright © 2010–2016, Texas Instruments Incorporated
Product Folder Links: CDCLVD1213
CDCLVD1213
www.ti.com
SCAS897A – JULY 2010 – REVISED OCTOBER 2016
Typical Application (continued)
9.2.1 Design Requirements
The CDCLVD1213 shown in Figure 15 is configured with a 156.25-MHz LVDS clock from the backplane as its
input frequency. The LVDS clock is AC-coupled. A resistor divider (and a 0.1-µF capacitor to reduce noise) is
used to set the bias voltage correctly at the VT pin. The configuration example is driving 4 LVDS receivers in a
line card application with the following properties:
• The PHY device is capable of DC-coupling with an LVDS driver such as the CDCLVD1213. This PHY device
features internal termination so no additional components are required for proper operation.
• The ASIC LVDS receiver features internal termination and operates at the same common-mode voltage as
the CDCLVD1213. Again, no additional components are required.
• The FPGA requires external AC-coupling, but has internal termination. 0.1-µF capacitors are placed to
provide AC-coupling.
• The CPU on output QD is internally terminated, and requires only external AC-coupling capacitors. The DIV
pin is pulled to ground with a 100-Ω resistor to set the frequency divider to 1 so that the CPU clock frequency
is also 156.25 MHz.
9.2.2 Detailed Design Procedure
See Input Termination for proper input terminations, dependent on single-ended or differential inputs.
See LVDS Output Termination for output termination schemes depending on the receiver application.
Unused outputs can be left floating.
In this example, the PHY, ASIC, and FPGA or CPU require different schemes. Power supply filtering and
bypassing is critical for low-noise applications.
See Power Supply Recommendations for recommended filtering techniques. A reference layout is provided in
Low-Additive Jitter, Four-LVDS-Outputs Clock Buffer With Divider EVM (SCAU044).
9.2.3 Application Curves
The CDCLVD12xx's low additive noise is shown in this line card application. The low noise 156.25-MHz source
with 67-fs RMS jitter drives the CDCLVD12xx, resulting in 80-fs RMS when integrated from 12 kHz to 20 MHz.
The resultant additive jitter is a low 44-fs RMS for this configuration.
Reference signal is low-noise Rohde and Schwarz SMA100A
Figure 16. CDCLVD12xx Reference Phase Noise,
67-fs RMS (12 kHz to 20 MHz)
Figure 17. CDCLVD12xx Output Phase Noise,
80-fs RMS (12 kHz to 20 MHz)
Submit Documentation Feedback
Copyright © 2010–2016, Texas Instruments Incorporated
Product Folder Links: CDCLVD1213
13
CDCLVD1213
SCAS897A – JULY 2010 – REVISED OCTOBER 2016
www.ti.com
10 Power Supply Recommendations
High-performance clock buffers are sensitive to noise on the power supply, which can dramatically increase the
additive jitter of the buffer. Thus, it is essential to reduce noise from the system power supply, especially when
jitter or phase noise is critical to applications.
Filter capacitors are used to eliminate the low-frequency noise from the power supply, where the bypass
capacitors provide the low impedance path for high-frequency noise and guard the power-supply system against
the induced fluctuations. These bypass capacitors also provide instantaneous current surges as required by the
device and must have low equivalent series resistance (ESR). To properly use the bypass capacitors, they must
be placed close to the power-supply pins and laid out with short loops to minimize inductance. TI recommends
adding as many high-frequency (for example, 0.1-µF) bypass capacitors as there are supply pins in the package.
TI recommends, but does not require, inserting a ferrite bead between the board power supply and the chip
power supply that isolates the high-frequency switching noises generated by the clock driver; these beads
prevent the switching noise from leaking into the board supply. Choose an appropriate ferrite bead with low DCresistance because it is imperative to provide adequate isolation between the board supply and the chip supply,
as well as to maintain a voltage at the supply pins that is greater than the minimum voltage required for proper
operation.
Figure 18 shows this recommended power-supply decoupling method.
Ferrite Bead
1 µF
10 µF
0.1 µF
Figure 18. Power-Supply Decoupling
14
Submit Documentation Feedback
Copyright © 2010–2016, Texas Instruments Incorporated
Product Folder Links: CDCLVD1213
CDCLVD1213
www.ti.com
SCAS897A – JULY 2010 – REVISED OCTOBER 2016
11 Layout
11.1 Layout Guidelines
For reliability and performance reasons, the die temperature must be limited to a maximum of 125°C.
The device package has an exposed pad that provides the primary heat removal path to the printed-circuit board
(PCB). To maximize the heat dissipation from the package, a thermal landing pattern including multiple vias to a
ground plane must be incorporated into the PCB within the footprint of the package. The thermal pad must be
soldered down to ensure adequate heat conduction to of the package. Figure 19 shows a recommended land
and via pattern.
11.2 Layout Example
Figure 19. Recommended PCB Layout
11.3 Thermal Considerations
The CDCLVD1213 supports high temperatures on the printed-circuit board (PCB) measured at the thermal pad.
The system designer must ensure that the maximum junction temperature is not exceeded. ΨJB can allow the
system designer to measure the board temperature with a fine gauge thermocouple and back calculate the
junction temperature using Equation 1. Note that ΨJB is close to RθJB as 75% to 95% of a device's heat is
dissipated by the PCB.
TJ = TPCB + ( ΨJB × Power)
(1)
Example:
Calculation of the junction-lead temperature with a 4-layer JEDEC test board using four thermal vias:
TPCB = 105°C
ΨJB = 19.4°C/W
PowerinclTerm = Imax × Vmax = 85 mA × 2.625 V = 223 mW (maximum power consumption including
termination resistors)
PowerexclTerm = 215 mW (maximum power consumption excluding termination resistors, see Power
Consumption of LVPECL and LVDS (SLYT127) for further details)
ΔTJ = ΨJB × PowerexclTerm = 19.4°C/W × 215 mW = 4.17°C
TJ = ΔTJ + TChassis = 4.17°C + 105°C = 109.17°C (maximum junction temperature of 125°C is not
violated)
Further information can be found at Semiconductor and IC Package Thermal Metrics (SPRA953) and Using
Thermal Calculation Tools for Analog Components (SLUA566).
Submit Documentation Feedback
Copyright © 2010–2016, Texas Instruments Incorporated
Product Folder Links: CDCLVD1213
15
CDCLVD1213
SCAS897A – JULY 2010 – REVISED OCTOBER 2016
www.ti.com
12 Device and Documentation Support
12.1 Documentation Support
12.1.1 Related Documentation
For related documentation see the following:
• Low-Additive Jitter, Four-LVDS-Outputs Clock Buffer With Divider EVM (SCAU044)
• Power Consumption of LVPECL and LVDS (SLYT127)
• Semiconductor and IC Package Thermal Metrics (SPRA953)
• Using Thermal Calculation Tools for Analog Components (SLUA566)
12.2 Receiving Notification of Documentation Updates
To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper
right corner, click on Alert me to register and receive a weekly digest of any product information that has
changed. For change details, review the revision history included in any revised document.
12.3 Community Resources
The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective
contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of
Use.
TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration
among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help
solve problems with fellow engineers.
Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and
contact information for technical support.
12.4 Trademarks
E2E is a trademark of Texas Instruments.
12.5 Electrostatic Discharge Caution
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
12.6 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
13 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
16
Submit Documentation Feedback
Copyright © 2010–2016, Texas Instruments Incorporated
Product Folder Links: CDCLVD1213
PACKAGE OPTION ADDENDUM
www.ti.com
10-Dec-2020
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
(4/5)
(6)
CDCLVD1213RGTR
ACTIVE
VQFN
RGT
16
3000
RoHS & Green
NIPDAU
Level-2-260C-1 YEAR
-40 to 85
D1213
CDCLVD1213RGTT
ACTIVE
VQFN
RGT
16
250
RoHS & Green
NIPDAU
Level-2-260C-1 YEAR
-40 to 85
D1213
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
