Texas Instruments LMX2581EVM User Manual
  1. Manuals
  2. Brands
  3. Texas Instruments Manuals
  4. Motherboard
  5. LMX2581EVM
  6. User manual
Texas Instruments LMX2581EVM User Manual

Texas Instruments LMX2581EVM User Manual

Hide thumbs

Advertisement

Table of Contents

LMX2581EVM
User's Guide
Literature Number: SNAU136C
November 2012 – Revised November 2013

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the LMX2581EVM and is the answer not in the manual?

Questions and answers

Subscribe to Our Youtube Channel

Related Manuals for Texas Instruments LMX2581EVM

Summary of Contents for Texas Instruments LMX2581EVM

  • Page 1 LMX2581EVM User's Guide Literature Number: SNAU136C November 2012 – Revised November 2013...
  • Page 2 User's Guide SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide The Texas Instruments LMX2581EVM evaluation module (EVM) helps designers evaluate the operation and performance of the LMX2581 Wideband Frequency Synthesizer. The EVM contains one Frequency Synthesizer. Converter: U1...
  • Page 3 R4 (removing power from the XO). Installing the EVM Software Go to http://www.ti.com/tool/codeloader and download and run the most current software. SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 4 Noise before burning in. Noise after burning in XO. Figure 2. Impact of Burning in the XO LMX2581EVM User's Guide SNAU136C – November 2012 – Revised November 2013 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 5 NOTE: To restore the device to its default settings at any time, load the default mode from the “Modes” menu. Figure 3. Loading Default Mode for the Main Configuration Screen SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 6 VCO frequency unless the OUTx_MUX bits on the Bits/Pins page are set Figure 4. Loading the device LMX2581EVM User's Guide SNAU136C – November 2012 – Revised November 2013 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...

  • Page 7: Port Setup

    Also note that the BUFEN pin does not work with the USB2ANY board because pin location 5 is reserved for other purposes. Be aware that the board has been revised and the port setup has changed. Figure 5. SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 8 Divider will ignored unless this is changed to “Channel Divider” Figure 6. Bits/Pins Settings LMX2581EVM User's Guide SNAU136C – November 2012 – Revised November 2013 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 9 FR4 material was chosen because of convenience, availability, and cost. If one was to use Rogers 4003 on the top Prepreg layer, the output power improves about 1 dB. Otherwise, the performance is very similar. SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 10 Assembly Variant: Sheet: warrant that this design will meet the specifications, will be suitable for your application or fit for any particular purpose, or will operate in an implementation. Texas Instruments and/or its Drawn By: Not shown in title block File: SV601009A.SchDoc...
  • Page 11 100 Ω differential trace can be grounded or it will change the desired 100 Ω termination for the differential trace. Out+ LMX2581 Out- OSCin 0.1 F 0.1 F Figure 10. Complementary OSCin Input Recommendation Diagram SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 12 VrefVCO 2.2µF Vtune C4_LF Vtune 3300pF VbiasVCO 2.2µF VccPlane VCCVCO 100pF VccPlane 120 ohm 100pF Figure 12. Vtune Input Diagram LMX2581EVM User's Guide SNAU136C – November 2012 – Revised November 2013 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 13 Vtune C4_LF Vtune 3300pF VbiasVCO 2.2µF VccPlane VCCVCO 100pF VccPlane 120 ohm 100pF Figure 14. Pins 18,19,22,23, and 24 Diagram SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 14 18nH 18nH 100pF 100pF 100pF 100pF 100pF 100pF RFoutB- RFoutA+ RFoutA- RFoutB+ 142-0701-851 142-0701-851 142-0701-851 142-0701-851 Figure 15. Outputs Diagram LMX2581EVM User's Guide SNAU136C – November 2012 – Revised November 2013 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...

  • Page 15: Pcb Layers

    PCB Layers Figure 16 shows the assembly diagram that indicates where the components are placed. Figure 16. Top Assembly Layer SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 16 Figure 17. Top Layer LMX2581EVM User's Guide SNAU136C – November 2012 – Revised November 2013 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 17 OSCin source. There is a connection through component L3 on the top layer. This reduces coupling from the OSCin signal to the outputs that can potentially spurs at +/- Foscin offset. Figure 18. Ground Layer SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 18 19, is used to route the power signals. There is a cutout below the OSCin signal to reduce any coupling the OSCin frequency from nearby vias to the power plane. Figure 19. Power Layer LMX2581EVM User's Guide SNAU136C – November 2012 – Revised November 2013 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 19 20, is used to route less critical functions. There are several optional components on the bottom layer, including the option to use an external VCO. Figure 20. Bottom Layer SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 20 XO. Comparing to the plot above, we see that the XO , not the LMX2581, is the dominant source of phase noise at 100 Hz and 1 kHz. Figure 22. Phase Noise (Default Mode) Plot 2 of 3 LMX2581EVM User's Guide SNAU136C – November 2012 – Revised November 2013 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 21 -155 dBc/Hz. Figure 23. Phase Noise (Default Mode) Plot 3 of 3 SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 22 Figure 24. VCO Phase Noise Fvco = 1900 MHz RFOutA+ Figure 25. VCO Phase Noise Fvco = 1900 MHz RFOutB+ LMX2581EVM User's Guide SNAU136C – November 2012 – Revised November 2013 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 23 Figure 26. VCO Phase Noise Fvco = 2200 MHz RFOutA+ Figure 27. VCO Phase Noise Fvco = 2200 MHz RFOutB+ SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 24 Figure 28. VCO Phase Noise Fvco = 2700 MHz RFOutA+ Figure 29. VCO Phase Noise Fvco = 2700 MHz RFOutB+ LMX2581EVM User's Guide SNAU136C – November 2012 – Revised November 2013 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 25 Figure 30. VCO Phase Noise Fvco = 3300 MHz RFOutA+ Figure 31. VCO Phase Noise Fvco = 3300 MHz RFOutB+ SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 26 Figure 32. Fvco = 2103 MHz (No Divide) Figure 33. Fvco = 2103 MHz/2 = 1051.5 MHz (Divide by 2) LMX2581EVM User's Guide SNAU136C – November 2012 – Revised November 2013 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 27 Figure 34. Fvco = 2403 MHz (No Divide) Figure 35. Frequency = 2403/2 = 1201.5 MHz (Divide by 2) SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 28 Figure 36. Fvco = 2703 MHz (No Divide) Figure 37. Frequency = 2703/2 = 1451.5 MHz (Divide by 2) LMX2581EVM User's Guide SNAU136C – November 2012 – Revised November 2013 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 29 Figure 38. Fvco = 3403 MHz (No Divide) Figure 39. Frequency = 3403/2 = 1051.5 MHz (Divide by 2) SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 30 This is the VCO calibration time and is independent of the loop filter. This can be dramatically improved by guiding the VCO to the correct frequency. Figure 40. LMX2581EVM User's Guide SNAU136C – November 2012 – Revised November 2013 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 31 This lock time can be decreased much further (<10 µs) if the OSCin and phase detector frequencies are raised. Figure 41. SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 32 This plot shows that this calibration is getting within about 200 kHz of the final frequency, so this is all the analog PLL has to settle out. Figure 42. LMX2581EVM User's Guide SNAU136C – November 2012 – Revised November 2013 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 33 Measured Performance Data www.ti.com Figure 43 shows the PLL settling to the final frequency. Figure 43. SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...

  • Page 34: Output Power

    The legend shows different values of the pull-up component that were used. LMX2581EVM User's Guide SNAU136C – November 2012 – Revised November 2013 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 35 Measured Performance Data www.ti.com Figure 46. SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 36 51 ohm resistor pull-up (OUTA). For the inductor pull-up (OUTB), a setting closer to 30 is more optimal. Figure 48. LMX2581EVM User's Guide SNAU136C – November 2012 – Revised November 2013 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 37 SINGLE-ENDED output power is +14.4 dBm! Figure 49. Figure 50 is the same board output at 2.2 GHz output. Figure 50. SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 38 This is more typical of a loop bandwidth that one would use for a clocking application or something with wider channel spacing. Figure 51. LMX2581EVM User's Guide SNAU136C – November 2012 – Revised November 2013 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...

  • Page 39: Bill Of Materials

    CRCW060318R0JNEA 0603 RES, 33 Ω, 5%, 0.1W, Vishay-Dale CRCW060333R0JNEA 0603 R23, R26 RES, 51 Ω, 5%, Vishay-Dale CRCW040251R0JNED 0.063W, 0402 SNAU136C – November 2012 – Revised November 2013 LMX2581EVM User's Guide Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...
  • Page 40 Gold-plated, SMD Vcc_TB Terminal Block, Weidmuller 1592820000 10.76x17x11 mm, 2POS, 26-12AWG, TH OSC 100.0000MHZ Connor-Winfield CWX813-100.0M 3.3 V +-25PPM SMD LMX2581EVM User's Guide SNAU136C – November 2012 – Revised November 2013 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...

  • Page 41: Revision History

    Added comments about use with external signal. NOTE: Page numbers for previous revisions may differ from page numbers in the current version. SNAU136C – November 2012 – Revised November 2013 Revision History Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated...

  • Page 42: Regulatory Compliance Information

    Any exceptions to this are strictly prohibited and unauthorized by Texas Instruments unless user has obtained appropriate experimental/development licenses from local regulatory authorities, which is responsibility of user including its acceptable authorization.
  • Page 43 FCC Interference Statement for Class B EVM devices This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications.
  • Page 44 Also, please do not transfer this product, unless you give the same notice above to the transferee. Please note that if you could not follow the instructions above, you will be subject to penalties of Radio Law of Japan. Texas Instruments Japan Limited (address) 24-1, Nishi-Shinjuku 6 chome, Shinjuku-ku, Tokyo, Japan http://www.tij.co.jp...
  • Page 45 FDA Class III or similar classification, then you must specifically notify TI of such intent and enter into a separate Assurance and Indemnity Agreement. Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright © 2013, Texas Instruments Incorporated...

  • Page 46: Important Notice

    IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue.
  • Page 47 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Texas Instruments LMX2581EVM...

Table of Contents