Texas Instruments LMX2492EVM, User Manual

Page 1: ... of a LMX2492 device a LP5900 3 3V LDO a 9 4 10 8 GHz VCO and a 100 MHz crystal oscillator The LMX2492 is a low noise 14 GHz wideband delta sigma fractional N PLL with ramp and chirp generation It consists of a phase frequency detector programmable charge pump and high frequency input for the external VCO The LMX2492 supports a broad and flexible class of ramping capabilities including FSK and con...

Page 2: ...Sawtooth Ramp Configuration 8 10 Continuous Sawtooth Ramp Example 9 11 Continuous Trapezoid Ramp Configuration 9 12 Flag Out Pins Configuration 10 13 Flags Out Timing 10 14 Continuous Trapezoid Ramp Example 10 15 Readback Setting 11 16 Register Readback 11 17 LMX2492EVM Schematic Page 1 12 18 LMX2492EVM Schematic Page 2 13 19 PCB Layer Stack up 14 20 Top Layer 14 21 GND Layer 15 22 Power Layer 15 ...

Page 3: ...1 2 Evaluation Setup Requirement The evaluation will require 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 A function waveform generator optional Texas Instruments Clocks and Synthesizers TICS Pro software Texas Instruments PLLatinum Simul...

Page 4: ...o operate with an external clock source In this case apply a single ended clock to the OSCin SMA connector or apply a differential clock to both OSCin and OSCin SMA connectors See Appendix B for details 2 4 RF Output Connect RFout 2 SMA connector to a spectrum analyzer or a signal analyzer By default the output signal frequency is 4 8 GHz and the amplitude is about 3 dBm Because the frequency accu...

Page 5: ...in TICS Pro 2 Go to Default configuration Default Mode xxxx xx xx Figure 3 Default Mode 2 7 EVM Strap Options The MUXout pin is not connected to the uWire header but is used as the lock detect indicator Other IO pins such as TRIG1 TRIG2 and MOD are connected to the uWire header They could be used as the input trigger sources or output flag indicators during frequency ramping Figure 4 IO Port ...

Page 6: ... Filter Configuration PARAMETER VALUE VCO frequency 9 4 10 8 GHz VCO gain 240 MHz V Effective charge pump gain 3 1 mA Phase detector frequency 100 MHz Loop bandwidth 435 kHz Phase margin 60 8 degrees C1_LF 68 pF C2_LF 3 9 nF C3_LF 150 pF C4_LF Open R2_LF 390 Ω R3_LF 150 Ω R4_LF 0 Ω Figure 5 Loop Filter 3 1 2 Typical Output 1 Follow Section 2 to setup the evaluation 2 Go to USB communications Write...

Page 7: ...Output 3 2 Additional Tests 3 2 1 Frequency Shift Keying FSK Example FSK operation requires an external input trigger signal at either MOD TRIG1 or TRIG2 pin In this example MOD pin is selected as the Trigger A source A 20 kHz square wave clock will be applied to MOD pin to toggle the RF output to switch between 9600 MHz and 9604 MHz That is FSK deviation is 4 MHz Figure 7 TICS Pro FSK Configurati...

Page 8: ...ight 2014 2017 Texas Instruments Incorporated LMX2492EVM Evaluation Module Figure 8 FSK Example 3 2 2 Continuous Sawtooth Ramp Example This example shows how to generate a continuous sawtooth ramp Only one ramp segment is necessary as it will loop back to itself Figure 9 Continuous Sawtooth Ramp Configuration ...

Page 9: ...2492EVM Evaluation Module Figure 10 Continuous Sawtooth Ramp Example 3 2 3 Continuous Trapezoid Ramp Example This is a long ramp example the ramp duration is 1 ms RAMPx_DLY is enabled so that the ramp generator will ramp every 2 phase detector cycles Output flags are turned on to indicate the start of a ramp Figure 11 Continuous Trapezoid Ramp Configuration ...

Page 10: ...ch 2014 Revised October 2017 Submit Documentation Feedback Copyright 2014 2017 Texas Instruments Incorporated LMX2492EVM Evaluation Module Figure 12 Flag Out Pins Configuration Figure 13 Flags Out Timing Figure 14 Continuous Trapezoid Ramp Example ...

Page 11: ...egister Readback To read back the written register values 1 Remove R75 so that the MUXout pin is disconnected from the LED 2 Populate R68 to connect MUXout pin to USB2ANY 3 In TICS Pro set MUXout pin to Output Readback Figure 15 Readback Setting 4 Click on the Register Name that you want to read back 5 Click the Read Register button to read back the register value Figure 16 Register Readback ...

Page 12: ...ww ti com 12 SNAU160E March 2014 Revised October 2017 Submit Documentation Feedback Copyright 2014 2017 Texas Instruments Incorporated LMX2492EVM Evaluation Module 4 Schematic Figure 17 LMX2492EVM Schematic Page 1 ...

Page 13: ...i com Schematic 13 SNAU160E March 2014 Revised October 2017 Submit Documentation Feedback Copyright 2014 2017 Texas Instruments Incorporated LMX2492EVM Evaluation Module Figure 18 LMX2492EVM Schematic Page 2 ...

Page 14: ...tack up www ti com 14 SNAU160E March 2014 Revised October 2017 Submit Documentation Feedback Copyright 2014 2017 Texas Instruments Incorporated LMX2492EVM Evaluation Module 5 PCB Layout and Layer Stack up 5 1 PCB Layer Stack up The top layer is 1 oz copper Figure 19 PCB Layer Stack up 5 2 PCB Layout Figure 20 Top Layer ...

Page 15: ...yout and Layer Stack up 15 SNAU160E March 2014 Revised October 2017 Submit Documentation Feedback Copyright 2014 2017 Texas Instruments Incorporated LMX2492EVM Evaluation Module Figure 21 GND Layer Figure 22 Power Layer ...

Page 16: ...ut and Layer Stack up www ti com 16 SNAU160E March 2014 Revised October 2017 Submit Documentation Feedback Copyright 2014 2017 Texas Instruments Incorporated LMX2492EVM Evaluation Module Figure 23 Bottom Layer ...

Page 17: ...le R2 R6 R7 3 RES 18 Ω 5 0 063 W 0402 CRCW040218R0JNED Vishay Dale R2_LF 1 RES 390 Ω 5 0 1 W 0603 CRCW0603390RJNEA Vishay Dale R3 1 RES 68 Ω 5 0 063 W 0402 CRCW040268R0JNED Vishay Dale R3_LF 1 RES 150 Ω 5 0 1 W 0603 CRCW0603150RJNEA Vishay Dale R4 1 RES 36 Ω 5 0 063 W 0402 CRCW040236R0JNED Vishay Dale R4_LF R15 R17 R18 R29 R30 R31 R32 R33 R35 R40 R44 R51 R60 14 RES 0 Ω 5 0 1 W 0603 CRCW06030000Z0E...

Page 18: ...s Verify communications x R WR 86 RPPXQLFDWLRQV QWHUIDFH ensure that the USB2ANY button is turned green OLFN 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 o...

Page 19: ... module is used at the first time TICS Pro will request for a firmware update Simply 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 setup otherwise the programming to LMX2492EVM will not be successful 1 When you see this message click the OK button Figure 25 Firmware Requirement 2 Next foll...

Page 20: ...as Instruments Incorporated USB2ANY Firmware Upgrade 3 If you don t know the location of the BSL button click the long button in the middle of the screen Figure 27 BSL Button 4 Click the OK button to go back to the previous screen Follow the on screen procedure until the below screen is pop up Figure 28 Update Firmware ...

Page 21: ...corporated USB2ANY Firmware Upgrade 5 Click the Upgrade Firmware button the firmware will be upgrading Click the Close button after it is done Figure 29 Firmware Update Completed 6 Check the USB connection in TICS Pro by clicking USB communications Interface Make sure the USB Connected button is turned green Figure 30 USB Communications ...

Page 22: ... March 2014 Revised October 2017 Using Different Reference Clock There are different options to provide a reference clock to LMX2492EVM By default the EVM is configured for the on board single ended XO clock To use external clock R21 and R28 must be removed If external differential clock is desired OSCin SMA connector is required Figure 31 Reference Clock Input Configuration ...

Page 23: ...ion History Revision History NOTE Page numbers for previous revisions may differ from page numbers in the current version Changes from D Revision September 2015 to E Revision Page Changed to use on board XO 4 Changed to use TICS Pro to program the device 4 Changed VCO frequency and VCO gain 6 Changed U2 part number 17 Added Appendix A 19 Added Appendix B 22 ...

Page 24: ...y set forth above or credit User s account for such EVM TI s liability under this warranty shall be limited to EVMs that are returned during the warranty period to the address designated by TI and that are determined by TI not to conform to such warranty If TI elects to repair or replace such EVM TI shall have a reasonable time to repair such EVM or provide replacements Repaired EVMs shall be warr...

Page 25: ...the user guide with the maximum permissible gain and required antenna impedance for each antenna type indicated Antenna types not included in this list having a gain greater than the maximum gain indicated for that type are strictly prohibited for use with this device Concernant les EVMs avec antennes détachables Conformément à la réglementation d Industrie Canada le présent émetteur radio peut fo...

Page 26: ...ed loads Any loads applied outside of the specified output range may also result in unintended and or inaccurate operation and or possible permanent damage to the EVM and or interface electronics Please consult the EVM user guide prior to connecting any load to the EVM output If there is uncertainty as to the load specification please contact a TI field representative During normal operation even ...

Page 27: ...COST OF REMOVAL OR REINSTALLATION ANCILLARY COSTS TO THE PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES RETESTING OUTSIDE COMPUTER TIME LABOR COSTS LOSS OF GOODWILL LOSS OF PROFITS LOSS OF SAVINGS LOSS OF USE LOSS OF DATA OR BUSINESS INTERRUPTION NO CLAIM SUIT OR ACTION SHALL BE BROUGHT AGAINST TI MORE THAN TWELVE 12 MONTHS AFTER THE EVENT THAT GAVE RISE TO THE CAUSE OF ACTION HAS OCCURRED 8 2 Specif...

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