Texas Instruments LMX2485E-EVM User manual

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SNAU114D–March 2006–Revised June 2016
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User's Guide
SNAU114D–March 2006–Revised June 2016
Using the LMX2485E & LMX2487E Evaluation Board
The Texas Instruments LMX2485E-EVM/LMX2487E-EVM helps designers evaluate the operation and
performance of any of the devices in the LMX248x family. Although only two options are offered, the other
members in the family are all pinout compatible and program compatible to one of these existing board
option. They would be expected to have similar performance, just different in the maximum frequency of
operation.
Topic ........................................................................................................................... Page
1 Setup.................................................................................................................. 2
2 Schematic........................................................................................................... 7
3 Bill of Materials.................................................................................................... 8
4 PCB Layers Stackup........................................................................................... 10
5 PCB Layout ....................................................................................................... 11
6 Typical Phase Noise Performance Plots................................................................ 13

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Table 1. Evaluation Device and Package Configurations
Device RF PLL Frequency Range Evaluation Vehicle
LMX2485E 50 to 3000 MHz LMX2485E EVAL
LMX2485 500 to 3000 MHz
LMX2486 1000 to 4500 MHz LMX2487E EVALLMX2487 1000 to 6000 MHz
LMX2487E 3000 to 7500 MHz
The EVM contains one Frequency Synthesizer (See Table 1).
Table 2. Evaluation Device and Package Configurations
Board Version Designator IC Package VCO Model VCO Frequency
Range
LMX2485E-EVM U1 LMX2485E QFN24 Crystek CVCO55CL 60-80 MHz
Crystem CVCO55BE-
1800-2200 1800-2200 MHz
LMX2487E-EVM U1 LMX2487E QFN24 Crystek CVCO44BH 4100-4300 MHz
Although the devices are very broadband, the VCO is ultimately what limits the frequency range of the
evaluation board. These VCOs were chosen primarily availability, standard footprint, and for lower risk of
being obsoleted.
WARNING! Due to availability issues, the LMX2485E-EVM has two different suppliers for VCO. Be
sure to check the VCO model number to know what VCO model you have!
1 Setup
Input/Output Connector Description.
Figure 1. Evaluation Board Setup

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VccVCO
Connect this to a 5 V Power supply.
OSCin
Connect this to a signal generator at +4 dBm. Default frequency is 50 MHz for the LMX2485E-EVM and
100 MHz for the LMX2487E-EVM.
RFout
Connect this to a spectrum analyzer. The board has DC blocking capacitors, so the signal is AC coupled.
uWire
Hook this to the programming interface.
1.1 Quick Start for EVM Communications
Codeloader is the software used to communicate with the EVM (Please download the latest version from
TI.com - http://www.ti.com/tool/codeloader). This EVM can be controlled through the uWire interface on
board. There are two options in communicating with the uWire interface from the computer.
Option 1
Figure 2. LPT Interface
Open Codeloader.exe →Click “Select Device” →Click “Port Setup” tab →Click “LPT” (in Communication
Mode).
Option 2
Figure 3. USB2ANY-uWire Adapter Board

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The Adapter Board
Table 3 describes the pins configuration on the adapter board for each EVM board (See examples in the
table below).
Table 3. Adapter Board Jumper Configuration
EVM Jumper Bank Code Loader Configuration
A B C D E F G H
LMX2581 A4 B1 C2 E5 F1 G1 H1 BUFEN (pin 1), Trigger (pin 7)
LMX2541 A4 C3 E4 F1 G1 H1 CE (pin 1), Trigger (pin 10)
LMK0400x A0 C3 E5 F1 G1 H1 GOE (pin 7)
LMK01000 A0 C1 E5 F1 G1 H1 GOE (pin 7)
LMK030xx A0 C1 E5 F1 G1 H1 SYNC (pin 7)
LMK02000 A0 C1 E5 F1 G1 H1 SYNC (pin 7)
LMK0480x A0 B2 C3 E5 F0 G0 H1 Status_CLKin1 (pin 3)
LMK04816/
4906 A0 B2 C3 E5 F0 G0 H1 Status_CLKin1 (pin 3)
LMK01801 A0 B4 C5 E2 F0 G0 H1 Test (pin 3), SYNC0 (pin 10)
LMK0482x
(prelease) A0 B5 C3 D 2E4 F0 G0 H1 CLKin1_SEL (pin 6), Reset (pin 10)
LMX2531 A0 E5 F2 G1 H2 Trigger (pin 1)
LMX2485/7 A0 C1 E5 F2 G1 H0 ENOSC (pin 7), CE (pin 10)
LMK03200 A0 E5 F0 G0 H1 SYNC (pin 7)
LMK03806 A0 C1 E5 F0 G0 H1
LMK04100 A0 C1 E5 F1 G1 H1
Example adapter configuration (LMK01801).
Figure 4. Example Adapter Board Configuration
Open Codeloader.exe →Click “Select Device” →Click “Port Setup” Tab →Click “USB” (in
Communication Mode) *Remember to also make modifications in “Pin Configuration” Section according to
Table above .
*Remember to also make modifications in “Pin Configuration” Section according to Table above.

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1.2 Loop Filter Values
TI’s Clock Design Tool can be used to optimize PLL phase noise/jitter for given specifications. See
http://www.ti.com/tool/codeloader.
1.3 RF PLL Loop Filter
Table 4. RF PLL Loop Filter Parameters
LMX2485E LMX2487E
VCO Used Crystek CVCO55CL Crystek CVCO55BH
VCO Gain 8 MHz/V 100 MHz/V
VCO Input Capacitance 330 pF 10 pF
Nominal Output Frequency 60 to 80 MHz 4100 to 4300 MHz
Phase Margin 44º 50º
Loop Bandwidth 8.7 kHz 15 kHz
Reference Clock Frequency 50 MHz 100 MHz
Kφ(Charge Pump) 16X (1520 μA) 8X (760 μA)
Phase Detector Freq 2000 kHz 20000 kHz
PLL Supply 3.3 V from LDO 3.3 V from LDO
VCO Supply 5 V 5 V
C1 10 nF 5.6 nF
C2 680 nF 120 nF
C3 15 nF 220 pF
C4 1 nF 1 nF
R2 180 Ω270 Ω
R3 220 Ω1.2 kΩ
R4 3.3 k Ω1.2 kΩ
The RF PLL loop filter parameters above are specifically for the VCO listed. If other VCO are used
instead, the values for these parameters will change.
For detailed design and simulation, please check our PLLatinum Sim Tool.

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1.4 Installing the EVM Software
Go to http://www.ti.com/tool/codeloader
Click on the download button to download the software.
Run the executable file.
Figure 5. Using the EVM Software
On the Port Setup tab, the user may select the type of communication port (USB or Parallel) that will be
used to program the device on the evaluation board. If parallel port is selected, the user should ensure
that the correct port address is entered.
Don’t forget to press <Ctrl>+L or do Keyboard Controls -> Load Device, to load the settings.

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2 Schematic
Figure 6. LMX2485E/87E-EVM Schematic
View Section 3 Bill of Materials for actual component values.

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3 Bill of Materials
Table 5. Bill of Materials
Item Designator Description Manufacturer Part Number Qty
1C18, C22, C24, C26, C30, C31,
C35, C41 CAP, CERM, 100pF, 25V, +/-
10%, X7R, 0603 AVX 06033C101KAT2A 8
2C5, C10, C11,
C14, C16, C17,
C25, C28, C29,
C36
CAP, CERM, 0.1uF, 16V, +/-
10%, X7R, 0603 Kemet C0603C104K4RACTU 10
3C1, C2, C3, C7, C8, C9, C37,
C40 CAP, CERM, 1uF, 16V, +/-10%,
X5R, 0603 Kemet C0603C105K4PACTU 8
4 C4, C19 CAP, CERM, 10uF, 10V, +/-
10%, X5R, 0805 Kemet C0805C106K8PACTU 2
5 D1 LED Lumex 1594540000 1
6 L1 FB, 120 ohm, 500mA, 0603 Murata BLM18AG121SN1D 1
7OSCin, RFout,
VccVCO Connector, SMT, End launch SMA 50 ohm Emerson Network Power 142-0701-851 3
8R3, R20, R21,
R23, R55 RES, 0 ohm, 5%, 0.1W, 0603 Vishay-Dale CRCW06030000Z0EA 5
9R1, R2, R4, R6, R7, R9, R10,
R12, R56 RES, 10.0 ohm, 1%, 0.1W, 0603 Vishay-Dale CRCW060310R0FKEA 9
10 R27, R29, R31 RES, 18 ohm, 5%, 0.1W, 0603 Vishay-Dale CRCW060318R0JNEA 3
11 R14 RES, 51 ohm, 5%, 0.1W, 0603 Vishay-Dale CRCW060351R0JNEA 1
12 R24,C21 RES, 10k ohm, 5%, 0.1W, 0603 Vishay-Dale CRCW060310K0JNEA 2
13 R43 RES, 270 ohm, 5%, 0.1W, 0603 Vishay-Dale CRCW0603270RJNEA 1
14 R32, R34, R35,
R36, R39 RES, 15k ohm, 5%, 0.1W, 0603 Vishay-Dale CRCW060315K0JNEA 5
15 R33, R37, R42,
R47 RES, 27k ohm, 5%, 0.1W, 0603 Vishay-Dale CRCW060327K0JNEA 4
16 U3 Ultra Low Noise, 150mA Linear
Regulator for RF/Analog Circuits
Requires No Bypass Capacitor,
6-pin LLP Texas Instruments LP5900SDX-3.3 1
18 U5 Low Noise, RRO Op Amp with
CMOS Input Texas Instruments LM6211MF 1
18 U7 NFET Fairchild BSS138 1
19 uWire Header FCI 52601-G10-8LF 1

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Table 6. Additional LMX2485E-EVM Specific Components
Item Designator Description Manufacturer Part Number Qty
20 U1 LMX2485E Texas Instruments LMX2485E 1
21 U2 VCO Crystek CVCO55CL-0060-0110 1
22 R45 RES, 15k ohm, 5%, 0.1W, 0603 Vishay-Dale CRCW060315K0JNEA 1
23 R46 RES, 27k ohm, 5%, 0.1W, 0603 Vishay-Dale CRCW060327K0JNEA 1
24 R50 RES, 0 ohm, 5%, 0.1W, 0603 Vishay-Dale CRCW06030000Z0EA 1
25 C1_RF CAP, CERM, 0.01uF, 100V, +/-5%,
X7R, 0603 Kemet C0603C103J1RACTU 1
26 C2_RF CAP, CERM, 0.68uF, 10V, +/-10%,
X5R, 0603 Kemet C0603C684K8PAC 1
27 C3_RF CAP, CERM, 0.015uF, 100V, +/-
10%, X7R, 0603 Kemet C0603C153K1RACTU 1
28 C4_RF CAP, CERM, 1000pF, 50V, +/-5%,
C0G/NP0, 0603 Kemet C0603C102J5GAC 1
29 R2_RF RES, 180 ohm, 5%, 0.1W, 0603 Vishay-Dale CRCW0603180RJNEA 1
30 R3_RF RES, 220 ohm, 5%, 0.1W, 0603 Vishay-Dale CRCW0603220RJNEA 1
31 R4_RF RES, 3.3k ohm, 5%, 0.1W, 0603 Vishay-Dale CRCW06033K30JNEA 1
Table 7. Additional LMX2487E-EVM Specific Componenents
Item Designator Description Manufacturer Part Number Qy
32 U1 LMX2487E Texas Instruments LMX2487E 1
33 U2 VCO Crystek CVCO55BH-4100-4300 1
35 C1_RF CAP, CERM, 5600pF, 100V,
+/-5%, X7R, 0603 AVX 06031C562JAT2A 1
36 C2_RF CAP, CERM, 0.12uF, 10V, +/-
10%, X5R, 0603 MuRata GRM188R61A124KA01D 1
37 C3_RF CAP, CERM, 220pF, 100V, +/-
10%, X7R, 0603 AVX 06031C221KAT2A 1
38 C4_RF CAP, CERM, 1000pF, 50V, +/-
5%, C0G/NP0, 0603 Kemet C0603C102J5GAC 1
39 R2_RF RES, 270 ohm, 5%, 0.1W,
0603 Vishay-Dale CRCW0603270RJNEA 1
40 R3_RF RES, 1.2k ohm, 5%, 0.1W,
0603 Vishay-Dale CRCW06031K20JNEA 1
41 R4_RF RES, 1.2k ohm, 5%, 0.1W,
0603 Vishay-Dale CRCW06031K20JNEA 1

FR-4 (Er = 4.8)
10 mil
Top Layer
RF Ground Plane]
FR4 (Er = 4.8)
23 mil
Power Plane #1
FR4
23 mil
Bottom Layer
62.2 mil thick
PCB Layers Stackup www.ti.com
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4 PCB Layers Stackup
6-layer PCB Stackup includes:
• Top Layer for high-priority high-frequency signals (2 oz)
• FR4 Dielectric, 10 mils
• RF Ground plane (1 oz)
• FR4, 23 mils
• Power plane #1 (1 oz)
• FR4, 23 mils
• Bottom Layer copper clad for thermal relief (2 oz)
Figure 7. PCB Layers