Texas Instruments LMX2820EVM User manual

User’s Guide
LMX2820EVM Evaluation Module
Noel Fung
ABSTRACT
The LMX2820EVM is designed to evaluate the performance of LMX2820. This board consists of a LMX2820
device.
The LMX2820 is a high-performance wideband synthesizer that can generate any frequency from 44.14 MHz to
22.6 GHz. The device runs from a single 3.3-V supply and has integrated LDOs that eliminate the need for
onboard low noise LDOs.
Table of Contents
1 Trademarks..............................................................................................................................................................................2
2 LMX2820EVM Evaluation Module..........................................................................................................................................3
2.1 Evaluation Module Contents.............................................................................................................................................. 3
2.2 Evaluation Setup Requirement.......................................................................................................................................... 3
2.3 Resources.......................................................................................................................................................................... 3
www.ti.com Table of Contents
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3 Setup........................................................................................................................................................................................4
3.1 Connection Diagram.......................................................................................................................................................... 4
3.2 Power Supply..................................................................................................................................................................... 4
3.3 Reference Clock.................................................................................................................................................................4
3.4 RF Output...........................................................................................................................................................................4
3.5 Programming......................................................................................................................................................................4
3.6 Evaluation Software........................................................................................................................................................... 5
4 Typical Measurement..............................................................................................................................................................6
4.1 Default Configuration......................................................................................................................................................... 6
4.2 Additional Tests.................................................................................................................................................................. 8
5 Schematic..............................................................................................................................................................................10
6 PCB Layout and Layer Stack-Up.........................................................................................................................................12
6.1 PCB Layer Stack-Up........................................................................................................................................................ 12
6.2 PCB Layout...................................................................................................................................................................... 12
7 Bill of Materials..................................................................................................................................................................... 15
8 Troubleshooting Guide.........................................................................................................................................................16
A Using Different Reference Clock........................................................................................................................................ 17
B USB2ANY Firmware Upgrade..............................................................................................................................................18
C Revision History...................................................................................................................................................................20
List of Figures
Figure 3-1. EVM Connection Diagram.........................................................................................................................................4
Figure 3-2. Select Device in TICS Pro.........................................................................................................................................5
Figure 3-3. Default Mode............................................................................................................................................................. 5
Figure 4-1. Loop Filter................................................................................................................................................................. 6
Figure 4-2. Default Output........................................................................................................................................................... 7
Figure 4-3. SYSREF Pulsed Mode Setting..................................................................................................................................8
Figure 4-4. Offset Mixing With PFDIN Pin Setting....................................................................................................................... 8
Figure 4-5. External VCO Mode Setting...................................................................................................................................... 9
Figure 4-6. Register Readback....................................................................................................................................................9
Figure 5-1. LMX2820EVM Schematic (Page 1).........................................................................................................................10
Figure 5-2. LMX2820EVM Schematic (Page 2).........................................................................................................................11
Figure 6-1. PCB Layer Stack-Up............................................................................................................................................... 12
Figure 6-2. Top Layer.................................................................................................................................................................12
Figure 6-3. RF GND Layer.........................................................................................................................................................13
Figure 6-4. Signal GND Layer................................................................................................................................................... 13
Figure 6-5. Bottom Layer........................................................................................................................................................... 14
Figure 8-1. Troubleshooting Guide............................................................................................................................................ 16
Figure B-1. Firmware Requirement........................................................................................................................................... 18
Figure B-2. Firmware Loader.....................................................................................................................................................18
Figure B-3. BSL Button..............................................................................................................................................................18
Figure B-4. Update Firmware.................................................................................................................................................... 19
Figure B-5. Firmware Update Complete.................................................................................................................................... 19
Figure B-6. USB Communications.............................................................................................................................................20
List of Tables
Table 4-1. Loop Filter Configuration.............................................................................................................................................6
Table 7-1. Bill of Materials..........................................................................................................................................................15
Table A-1. Reference Clock Input Configuration........................................................................................................................17
1 Trademarks
PLLatinum™ is a trademark of Texas Instruments.
All trademarks are the property of their respective owners.
Trademarks www.ti.com
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2 LMX2820EVM Evaluation Module
2.1 Evaluation Module Contents
In the box, there is:
• One LMX2820EVM board (HSDC060-001)
• One USB2ANY (HPA665)
• One USB cable
• One 10-pin ribbon cable
2.2 Evaluation Setup Requirement
The evaluation requires the following hardware and software:
• A DC power supply
• A spectrum analyzer or a signal analyzer
• A PC running Windows 7 or more recent version
• An oscilloscope (optional)
• A high quality signal generator (optional)
• Texas Instruments Clocks and Synthesizers TICS Pro software
• Texas Instruments PLLatinum™ Simulator Tool (optional)
2.3 Resources
Related evaluation and development resources are as follows:
•TICS Pro software
•PLLatinum Simulator Tool (PLL Sim)
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3 Setup
3.1 Connection Diagram
HPA665
USB2ANY
Texas Instruments
50 
Figure 3-1. EVM Connection Diagram
3.2 Power Supply
Apply 3.3 V to the J8 header. The acceptable supply voltage range is 3.2 V to 3.4 V.
3.3 Reference Clock
Connect the OSCINP SMA connector to a high-quality, 100-MHz signal source. The OSCINN SMA connector
can be left open because the OSCIN_N pin is terminated onboard.
The EVM is configured for single-ended input with the OSCIN_P pin connected to the OSCINP SMA connector
and the OSCIN_N pin 50-Ω terminated onboard. If required, the EVM can be modified to operate with a different
clock source in a different configuration. See Appendix A for more details.
3.4 RF Output
Connect either the RFOUTAP or RFOUTAN SMA connector to a signal analyzer. The unused connector must be
terminated with a 50-Ω resistor or SMA load. Output frequency is 6 GHz and the amplitude is about +3 dBm.
By default, the TICS Pro evaluation software has RFOUTB power down. These SMA connectors can be left
open.
3.5 Programming
Connect the ribbon cable from the USB2ANY to the LMX2820EVM.
Connect the USB cable from a PC to USB port in the USB2ANY. This provides power supply to the USB2ANY
and communication with the TICS Pro. A firmware update may be required. See Appendix B for more details.
Setup www.ti.com
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3.6 Evaluation Software
Download and install TICS Pro to a PC.
Run the software and follow these steps to start the program.
1. Go to Select Device → PLL + VCO → LMX2820.
Figure 3-2. Select Device in TICS Pro
2. The "ReadMe" page will load. Please take a minute to read the content to have a basic understanding of the
GUI.
3. Go to Default Configuration → EVM Default Mode.
Figure 3-3. Default Mode
www.ti.com Setup
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4 Typical Measurement
4.1 Default Configuration
4.1.1 Loop Filter
The parameters for the loop filter are listed in Table 4-1.
Table 4-1. Loop Filter Configuration
PARAMETER VALUE
C1_LF 470 pF
C2_LF 68 nF
C3_LF 2.2 nF
R2_LF 68.1 Ω
R3_LF 18.2 Ω
Figure 4-1. Loop Filter
Typical Measurement www.ti.com
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4.1.2 Typical Output
1. Follow Section 3 to set up the evaluation.
2. Click Write All Registers to write all the registers to LMX2820.
The default output is 6 GHz.
Figure 4-2. Default Output
www.ti.com Typical Measurement
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4.2 Additional Tests
4.2.1 SYSREF Example
The SROUT of LMX2820 can be used to generate or duplicate SYSREF signal. The output of SROUT can be a
single pulse, series of pulse, or a continuous stream of pulses. These pulses are synchronous with the RFOUT
signal with an adjustable delay. To use the SYSREF capability, the PLL must be in phase SYNC mode with
PHASE_SYNC_EN = 1. Here is an example of Pulsed mode.
Figure 4-3. SYSREF Pulsed Mode Setting
4.2.2 Offset Mixing With PFDIN Pin
The LMX2820 supports offset mxing with PFDIN pin. In this mode, the internal N divider is bypassed.
When using offset mixing with PFDIN pin, the phase detector must operate with a single PFD. As a result, the
charge pump current is equal to half the current setting made in register CPG.
Figure 4-4. Offset Mixing With PFDIN Pin Setting
Typical Measurement www.ti.com
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4.2.3 External VCO Mode
In addition to the internal VCO, LMX2820 also support working with an external VCO. The polarity of the phase
detector has to be set properly to match with the actual Vtune characteristic. The LMX2820EVM offers various
options to implement passive or active loop filter onboard.
Figure 4-5. External VCO Mode Setting
4.2.4 Register Readback
To read back the written register values, follow these steps:
1. Click the Register Name that you want to read back.
2. Click Read Register to read back the register value.
Figure 4-6. Register Readback
www.ti.com Typical Measurement
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5 Schematic
Figure 5-1. LMX2820EVM Schematic (Page 1)
Schematic www.ti.com
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Figure 5-2. LMX2820EVM Schematic (Page 2)
www.ti.com Schematic
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6 PCB Layout and Layer Stack-Up
6.1 PCB Layer Stack-Up
The top layer is 1-oz. copper.
Top layer
RO4350B (Er = 3.66)
RF GND layer
FR4 (Er = 4.2)
FR4 (Er = 4.2)
Bottom layer
62 mil
Signal GND layer
10 mil
Figure 6-1. PCB Layer Stack-Up
6.2 PCB Layout
Figure 6-2. Top Layer
PCB Layout and Layer Stack-Up www.ti.com
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Figure 6-3. RF GND Layer
Figure 6-4. Signal GND Layer
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Figure 6-5. Bottom Layer
PCB Layout and Layer Stack-Up www.ti.com
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7 Bill of Materials
Table 7-1. Bill of Materials
DESIGNATOR QTY DESCRIPTION PART NUMBER MANUFACTURER
C1LF 1 CAP, CERM, 470 pF, 10 V,+/- 5%, C0G/
NP0, 0603
885012006012 Wurth Elektronik
C2, C4, C8, C12, C14, C18, C20,
C23, C32, C33, C34
11 CAP, CERM, 0.1 µF, 16 V, +/- 10%, X5R,
0201
GRM033R61C104K
E84D
MuRata
C2LF 1 CAP, CERM, 0.068 µF, 25 V,+/- 10%,
X7R, 0603
885012206070 Wurth Elektronik
C3, C5, C9, C27 4 CAP, CERM, 10 µF, 10 V,+/- 10%, X5R,
0603
GRM188R61A106K
AALD
MuRata
C3LF 1 CAP, CERM, 2200 pF, 16 V, +/- 10%,
X7R, 0603
885012206036 Wurth Elektronik
C10, C15, C16, C24, C35 5 CAP, CERM, 0.1 µF, 10 V,+/- 10%, X5R,
0201
530Z104KT10T American Technical
Ceramics
C11, C13, C17, C19, C21, C22, C25,
C26, C28, C30, C31
11 CAP, CERM, 1 µF, 25 V, +/- 10%, X5R,
0402
GRM155R61E105K
A12D
MuRata
C29 1 CAP, CERM, 0.47 µF, 25 V, +/- 10%, X7R,
AEC-Q200 Grade 1, 0603
CGA3E3X7R1E474
K080AB
TDK
D1 1 LED, Green, SMD LTST-C190GKT Lite-On
J1 1 Header, 100mil, 3x1, Gold, TH TSW-103-07-G-S Samtec
J2 1 Header (shrouded), 100mil, 5x2, Gold,
SMT
52601-S10-8LF FCI
J8 1 Header, 100mil, 2x1, Gold, TH TSW-102-07-G-S Samtec
J10, J11, J12, J13, J15, J16, J19 7 JACK, SMA, 50 Ohm, Gold, Edge Mount 142-0771-831 Cinch Connectivity
J14, J18 2 CONN SMA JACK STR EDGE MNT CON-SMA-EDGE-S RF Solutions Ltd.
R1 1 RES, 1.0 k, 5%, 0.1 W, AEC-Q200 Grade
0, 0603
CRCW06031K00JN
EA
Vishay-Dale
R2, R4, R5, R6, R7, R8, R9 7 RES, 33, 5%, 0.1 W, AEC-Q200 Grade 0,
0603
CRCW060333R0JN
EA
Vishay-Dale
R2LF 1 RES, 68.1, 1%, 0.1 W, AEC-Q200 Grade
0, 0603
CRCW060368R1FK
EA
Vishay-Dale
R3LF 1 RES, 18.2, 1%, 0.1 W, AEC-Q200 Grade
0, 0603
CRCW060318R2FK
EA
Vishay-Dale
R15 1 RES, 330, 5%, 0.1 W, AEC-Q200 Grade
0, 0603
CRCW0603330RJN
EA
Vishay-Dale
R18, R21, R22, R23, R24, R25, R26,
R27, R28, R37
10 RES, 0, 5%, 0.1 W, AEC-Q200 Grade 0,
0603
CRCW06030000Z0
EA
Vishay-Dale
R30, R32 2 RES, 0, 5%, 0.05 W, 0201 CRCW02010000Z0
ED
Vishay-Dale
R31, R35, R40 3 RES, 49.9, 1%, 0.1 W, AEC-Q200 Grade
0, 0603
CRCW060349R9FK
EA
Vishay-Dale
SH-J1 1 Shunt, 100mil, Gold plated, Black SNT-100-BK-G Samtec
TP1, TP2, TP3, TP4, TP5, TP6, TP7,
TP8, TP9
9 Test Point, Miniature, White, TH 5002 Keystone
TP11 1 Test Point, Miniature, Black, TH 5001 Keystone
TP12 1 Test Point, Miniature, Red, TH 5000 Keystone
U1 1 RF Synthesizer LMX2820 Texas Instruments
www.ti.com Bill of Materials
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8 Troubleshooting Guide
If the EVM does not work as expected, use Figure 8-1 to identify potential root causes. Consider the following:
• Do not make modifications to the EVM or change the default settings until AFTER it is verified to be working.
• Register read back requires the correct software setup. See Section 4.2.4 for details.
• The POR current of the LMX2820EVM is approximately 220 mA.
• The power-down current of the LMX2820EVM is approximately 10 mA.
Device locked Congratulation!
Start
Yes
Verify hardware setup:
x Validate power supply is connected, turned on, and current limit is appropriate for the device.
x Validate OSCin signal is supplied and turned on, if required.
x Ensure programming cable is hooked up to the board.
x Ensure spectrum analyzer center frequency matches target frequency. Choose wide span so that the carrier can
be seen if it is off frequency.
x Ensure device is not powered down by the CE pin.
x Load all registers (Ctrl+L).
Device locked Congratulation!
No
Yes
Verify software setup:
x 5HYHUWWRGHIDXOWPRGHLQWKHVRIWZDUHXQGHU³'HIDXOW&RQILJXUDWLRQ´.
x Validate that no boxes are red. If so, mouse over and read the tool tips.
x Ensure that all the frequency boxes values are correct. Also understand that the VCO frequency could be
different than the output frequency as there are often dividers after the boxes.
x Load all registers (Ctrl+L).
x Try Readback at this point, if necessary.
Device locked Congratulation!
No
Yes
Verify communications:
x *RWR³86%&RPPXQLFDWLRQV´, ³,QWHUIDFH´, ensure that the USB2ANY button is turned green. &OLFN³,GHQWLI\´WR
have the program blink the green LED.
x Send simple one way communication to the device such as: POWERDOWN, RESET, or change the status of a
pin. Realize that if a RESET is done, do a Ctrl+L to refresh the registers afterwards. For POWERDOWN, you can
validate this looking at the current on the power supply.
Device locked Congratulation!
No
Yes
No
Contact TI support
www.ti.com/support
Figure 8-1. Troubleshooting Guide
Troubleshooting Guide www.ti.com
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A Using Different Reference Clock
These are the different options to provide a reference clock to LMX2820EVM. By default, the EVM is configured for an external single-ended clock.
Table A-1. Reference Clock Input Configuration
DIFFERENTIAL CLOCK SINGLE-ENDED CLOCK
www.ti.com Using Different Reference Clock
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B USB2ANY Firmware Upgrade
Usually when the USB2ANY module is used the first time, TICS Pro will request a firmware update. Follow the
pop-up instructions to complete the update. This is necessary to ensure that the USB connection between the
PC and the USB2ANY module is properly set up, otherwise the programming to LMX2820EVM will not be
successful.
1. When the USB2ANY Firmware Requirement pop-up window appears, click OK to continue.
Figure B-1. Firmware Requirement
2. Next, follow the on-screen procedure shown in Figure B-2.
Figure B-2. Firmware Loader
3. If you do not know the location of the BSL button, click the Help me locate the BSL Button (S1) button to
launch the USB2ANY BSL Button (S1) Location pop-up window.
Figure B-3. BSL Button
USB2ANY Firmware Upgrade www.ti.com
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4. Click OK to close out of the USB2ANY BSL Button (S1) Location pop-up window and return to the previous
screen. Follow the on-screen procedure until the Update Firmware screen appears.
Figure B-4. Update Firmware
5. Click Upgrade Firmware to start the firmware upgrade. Click Close after the upgrade is complete.
Figure B-5. Firmware Update Complete
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6. Go to USB communications → Interface in the TICS Pro software to check the USB connection. Make sure
the USB Connected button is green.
Figure B-6. USB Communications
C Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision * (June 2020) to Revision A (January 2021) Page
• Updated the numbering format for tables, figures, and cross-references throughout the document. Updated
the operating frequency range............................................................................................................................1
• Updated graphics and added description to the ReadMe page to the Evaluation Software section.................. 5
• Updated graphic in SYSREF Example section...................................................................................................8
• Updated graphic and changed external PFD mode to offset mixing with PFDIN pin in the Offset Mixing With
PFDIN Pin section.............................................................................................................................................. 8
• Updated graphic in External VCO Mode section................................................................................................ 9
Revision History www.ti.com
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