DC2248A - Demo Manual

DEMO MANUAL DC2248A
LTC6951
Ultralow Jitter Multi-Output Clock
Synthesizer with Integrated VCO
Description
Demonstration circuit 2248A features the LTC®6951,
an Ultralow Jitter Multi-Output Clock Synthesizer with
Integrated VCO.
For ease of use, the DC2248A is powered from a single
6V supply and comes installed with a 100MHz reference.
Direct access to the LTC6951 5V, 3.3V and the reference
supplies is possible by removing jumpers. For evaluation of the LTC6951 with other references, the DC2248A
can be modified to accommodate different onboard or
external components.
All differential inputs and outputs have 0.5" spaced SMA
connectors. The DC2248A has four AC coupled CML outputs with 50Ω transmission lines making them suitable
to drive 50Ω impedance instruments. The LVDS output
is DC coupled.
The LTC6951’s synchronization functions are made available via the LTC6951 SPI interface, an SMA connector and
a turret. The DC2248A can be modified to use an onboard
switch and debounce circuit to control the sync pin.
A DC2026 (or DC590B) USB serial controller board is used
for SPI communication with the LTC6951, controlled by
the supplied LTC6951Wizard™ software.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2248A
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
LT6951Wizard, EZSync ParallelSync and QuikEval are trademarks of Linear Technology
Corporation. All other trademarks are the property of their respective owners.
OUT4, LVDS
DC-COUPLED
OUTPUTS, SMA
OUT3, CML
AC-COUPLED
OUTPUTS, SMA
RIBBON CABLE
CONNECTION
TO DC590
OUT0, CML
AC-COUPLED
OUTPUTS, SMA
SUPPLY OPTION,
JUMPERS,
REFER TO DC2248
RECONFIGURATION
OUT1, CML
AC-COUPLED
OUTPUTS, SMA
SINGLE SUPPLY
6V – 9V INPUT,
BANANA JACKS,
DEFAULT OPTION
OUT2, CML
AC-COUPLED
OUTPUTS, SMA
FREQUENCY REFERENCE OPTION,
SMA AND TURRET,
REFER TO DC2248 RECONFIGURATION
SYNC INPUT,
SMA AND TURRET,
DEFAULT OPTION
SYNC OPTION, ONBOARD
SWITCH AND DEBOUNCE CIRCUIT
REFER TO DC2248 RECONFIGURATION
Figure 1. DC2248A Connections
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1
DEMO MANUAL DC2248A
Quick Start Procedure
The DC2248A is easy to set up to evaluate the performance
of the LTC6951. Follow the procedure below.
LTC6951Wizard Installation
DC2026 and DC590B Configuration
The LTC6951Wizard software is used to communicate with
the LTC6951. It uses the DC2026 (or DC590B) to translate
between USB and SPI-compatible serial communications
formats. It also includes advanced PLL design and simulation capabilities. The following are the LTC6951Wizard
system requirements:
DC2026: Refer to Figure 2. Set the JP3 jumper to the 3.3V
(preferred) or 5V position.
• Windows Operating System: Windows XP, Windows
2003 Server, Windows Vista, Windows 7
DC590B: Refer to Figure 2. Set the JP6 jumper to the 3.3V
(preferred) or 5V position. JP4 should select “EN”, JP5
“ISO” and “SW” should both select “ON.”
• Microsoft .NET 3.5 SP1 or later
The LTC6951Wizard and the DC2026 (or DC590B) are
required to control the DC2248A through a personal
computer (PC).
Connect either the DC2026 (or DC590B) to one of your
computer’s USB ports with the included USB cable.
The DC2026 has the ability to run Linduino code. Refer to
http://www.linear.com/solutions/linduino and the Frequently
Asked Question section (Question #3) for more details.
• Windows Installer 3.1 or later
• Linear Technology’s® DC590B or DC2026 (with the
DC590B emulator sketch loaded)
The DC2026 arrives from the factory with the DC590B
emulator sketch loaded. If this is not the case refer to the
Troubleshooting section.
J1 (DC2026), J4 (DC590B)
RIBBON CABLE CONNECTION TO PC
J5, USB
CONNECTION
TO PC
J3, USB
CONNECTION
TO PC
JP3 (DC2026), JP6 (DC590B)
SELECT 3.3V OPTION
JP5
JUMPER
JP4
JUMPER
Figure 2. DC2026B and DC590B Jumper and Connector Location
2
dc2248af
DEMO MANUAL DC2248A
Quick Start Procedure
Download the LTC6951Wizard setup file at www.linear.
com/LTC6951Wizard.
2. Connect the DC2026 (or DC590B) to the DC2248A with
the provided ribbon cable.
Run the LTC6951Wizard setup file and follow the instructions given on the screen. The setup file will verify and/or
install Microsoft .NET and install the LTC6951Wizard. Refer
to the LTC6951Wizard Help menu for software operation.
3.Run the LTC6951Wizard application.
DC2248A Configuration
4.In LTC6951Wizard, click File → Load Settings and select
file “ALL_CHAN_600MHz.6951set”. The DC2248A’s
red STATUS LED (D1) should illuminate after step 4. A
600MHz signal should be present on all outputs.
1.Connect J15 and J16 to a power supply and apply power
(see Figure 1 and the Typical DC2248A Requirements
and Characteristics table). The three green power supply
LEDs (D2, D3, D4) should illuminate at this point.
Be sure to power down or terminate any unused RF output
with 50Ω, or poor spurious performance may result.
5.Synchronize outputs by toggling the LTC6951 SSYNC
bit from the LTC6951Wizard.
Figure 3. LTC6951Wizard Screenshot
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3
DEMO MANUAL DC2248A
Troubleshooting
If the green LEDs (D2, D3, or D4) do not illuminate:
1. Verify J15 measures between 6V and 9V (see the Typical
DC2248A Requirements and Characteristics table).
2. Verify JP1, JP2, JP3 jumpers are installed correctly
(refer to the DC2248A schematic sheet 3).
3. Verify the voltages at JP1, JP2, and JP3 are correct:
a. JP1 = 3.3V
b.JP2 = 5V
c. JP3 = 3.3V
If the red LED (D1) does not illuminate:
1. In LTC6951Wizard’s System tab click “Read All’.
LTC6951Wizard should match Figure 3. If not, see
“Verify DC2248A and LTC6951Wizard Communication.”
2. In LTC6951Wizard’s System tab, Under Status deselect
LOCK and select REFOK. If D1 was does not illuminate
then verify “V+XO” test point reads 3.3V.
5. If using the DC2026, Verify the DC2026 has the DC590B
Emulator sketch loaded by contacting the factory or
following these steps.
a. Download QuikEval™ at
http://www.linear.com/designtools/software/#Data
b.Run QuikEval (Linduino connected to the PC)
If QuikEval does not find a DC590B, reload the DC590
Linduino sketch. To use the LTSketchbook refer to the Linduino Quick Start tab at http://www.linear.com/solutions/
linduino for instructions on how to start using Linduino.
If DC2248A performance is less than the LTC6951
data sheet specifications or LTC6951Wizard
Simulation:
1. For unexpected spurious response, verify power supplies are low noise and spurious free power supplies.
Power supplies that are based off a switching regulator
architecture are known to generate spurs on PLL/VCO
outputs.
1. Ensure the DC2026 (or DC590B) is connected to PC.
2. For poor phase noise results, verify the phase noise
specifications of the phase noise measurement instrument. Traditional spectrum analyzers have higher phase
noise than the LTC6951 and will degrade measurement
results. To measure phase noise performance it is
recommended to use a signal source analyzer, such
as Keysight’s (previously Agilent/HP) E5052.
2. Disconnect and Reconnect DC2026 (or DC590B) to PC.
Contact the factory for further troubleshooting.
Verify DC2248A and LTC6951Wizard Communication:
To verify communication with the DC2248A, the bottom
status line in LTC6951Wizard should read “LTC6951”
and “Comm Enabled” as shown in Figure 3. If not, then
perform the following steps:
3. Ensure DC2026 (or DC590B) is connected to DC2248A.
4. Close LTC6951Wizard and restart.
4
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DEMO MANUAL DC2248A
dc2248A Reconfiguration
The following covers the hardware reconfiguration of the
DC2248A. Refer to LTC6951Wizard and the LTC6951 data
sheet to better understand how to change programmed
parameters on the DC2248A.
Power Supply Options
Table 1 provides the power supply options for DC2248A.
Any combination of onboard LDO or external supplies
is possible. By default the DC2248A is set up to use the
three onboard LDO’s.
Table 1. Power Supply Options
VOLTAGE,
COMPONENTS
JUMPER
3.3V*,
U2 100MHz reference
JP1
5V,
U1 LTC6951
JP2
3.3V,
U1 LTC6951, U3, U4,
U5 and U9
JP3
ONBOARD LDO
EXTERNAL
SUPPLY
Short Jumper
Pins 1–2.
Apply 6V–9V to
J15/J16.
(Default Option).
Short Jumper
Pins 2–3. Apply
appropriate
voltage to
Jumper Pin 1.
Reference Options
Table 2 details the available reference options and board
modifications for each available option. The 6951set files
provided assume the frequency and noise profile of the
default reference. If a different reference is used, update the
reference frequency and noise profile in LTC6951Wizard
before simulating the LTC6951 under the Loop Design tab
(see Frequently Asked Questions section, question #3 and
the LTC6951Wizard Help menu).
Sync Options
The LTC6951 data sheet describes several synchronization modes. After selecting the desired synchronization
mode, refer to Tables 3 and 4 to select a synchronization
programming option and the resulting DC2248A board
modifications. Refer to the LTC6951 data sheet for SYNC
timing and level requirements.
CML Outputs (OUT0, OUT1, OUT2, OUT3)
* When using an external reference, power down the onboard reference
by shorting JP1 pins 2–3, or poor spurious performance may result.
LTC6951 6951SET Files
The LTC6951Wizard provides a 6951set file for all LTC6951
data sheet application examples and typical application
circuits. After loading a 6951 set file a pop-up window will
detail any user actions and board modifications required
for the selected file. These same user actions and board
modifications are listed in Table 5.
The DC2248A has four AC coupled CML outputs. To drive
50Ω impedance instruments connect OUTx+ to the instrument and OUTx– to a 50Ω termination, or vice versa. Refer
to LTC6951 data sheet for differential termination options.
The V+BIAS turret provides an option to set the DC offset
level after the AC coupling capacitor. Modifications are
required to use the V+BIAS turret; refer to the DC2248A
schematic.
LVDS Output (OUT4)
Loop Filter Design and Installation
Use 6951Wizard to select, design and simulate different
loop filters (see Frequently Asked Questions section, question #3). Loop filter components RZ, CI1, CI2, CP, L1 and
R1 are located on the top side of the board. Loop filter
component C2 is located on the bottom side of the board.
The LVDS output is DC coupled without onboard termination by default. The DC2248A provides series and a
differential termination resistor options to accommodate
other termination networks described in the data sheet.
Table 2. Reference Options and Board Modifications
DEFAULT REFERENCE OPTION
OPTION
l
INSTALL
DEPOPULATE
LTC6951 PERFORMANCE
COMMENTS
Onboard
NA
NA
Limited by onboard reference
at frequency offsets <10kHz
U2 reference footprint supports 5mm x 7.5mm
and 14mm x 9mm packages with 4 or 6 pins
External*
C36
0402 1µF
C35
Best performance when using
an ultralow noise external
reference
For improved performance connect J12 to an
ultralow noise reference, such as the Wenzel
501-04517D.
* When using an external reference, power down the onboard reference by shorting JP1 pins 2-3, or poor spurious performance may result.
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DEMO MANUAL DC2248A
dc2248A Reconfiguration
Table 3. LTC6951 Sync Mode Programming Options
SYNC PROGRAMMING OPTIONS
(See Table 4 for Board Modifications)
LTC6951
RAO BIT
LTC6951
SSYNC BIT
ONBOARD
SYNC SWITCH
(SW1)*
SYNC SMA
SYNC SMA
AND REF+ SMA
EZSync, STANDALONE
0
l
l
l
l
EZSync, CONTROLLER
0
l
l
l
EZ204Sync
1
l
l
l
l
EZParallelSync
1
l
l
l
l
ParallelSync
1
LTC6951 SYNC MODE
COMMENTS
Modify follower-driver outputs to be DC-coupled,
refer to LTC6951 and follower part number data
sheets for correct termination networks.
l
* SW1 output is connected to a debounce circuit to ensure the SYNC pin receives a clean sync signal
Table 4. DC2248A Board Modifications for LTC6951 Sync Programming Options
DEFAULT SYNC PROGRAMMING
OPTION OPTION
l
R13
LTC6951 SSYNC bit
R54
U2, REFERENCE
COMMENTS
1kΩ
Do Not Install Onboard or External, See Table 2 Refer to LTC6951 data sheet for EZSync timing
Onboard or External, see Table 2 requirements.
Onboard Sync Switch (SW1) Depopulate
0Ω
SYNC SMA
Depopulate Do Not Install Onboard or External, see Table 2
SYNC SMA and REF+ SMA
Depopulate Do Not Install External Only, see Table 2
When using ParallelSync™ refer to LTC6951
data sheet for REF+ and SYNC pins timing
requirements.
Table 5. LTC6951Wizard Settings File
LTC6951Wizard FILE NAME
USER ACTIONS
BOARD MODIFICATIONS
ALL_CHAN_600MHz
Toggle LTC6951 SSYNC register bit
NA
6951_EZSYNC_STANDALONE
6951-1_EZSYNC_STANDALONE
Toggle LTC6951 SSYNC register bit
NA
6951_EZSYNC_MULTI-CHIP
6951-1_EZSYNC_MULTI-CHIP
Toggle LTC6951 & LTC6954 SYNC Pin (EZSync timing)
Refer to Tables 3 (EZSync CONTROLLER) and 4
6951_ParallelSync_MULTI-CHIP
6951-1_ParallelSync_MULTI-CHIP
Toggle LTC6951 CAL register bit
Toggle LTC6951 SYNC pin (SYNC to REF timing)
Refer to Table 2 (External Reference)
Refer to Tables 3 (ParallelSync) and 4
Loop Filter (values provided in LTC6951Wizard File)
6951_JESD204B
6951-1_JESD204B
Toggle LTC6951 SSYNC register bit
Refer to Table 2 (External Reference)
Loop Filter (values provided in LTC6951Wizard File)
6951_FrontPage_LTC2107
NA
NA
6951_ParallelSyncw6954
Toggle LTC6951 CAL register bit
Toggle LTC6951 SYNC pin (SYNC to REF timing)
Refer to Tables 3 (ParallelSync) and 4
6951_JESD204B_LTC2123
Toggle LTC6951 SSYNC register bit
NA
6
dc2248af
DEMO MANUAL DC2248A
Assembly Options
Table 6. DC2248A Options and Frequency Ranges
ASSEMBLY VERSION
PART NUMBER
FREQUENCY RANGE
DC2248A-A
LTC6951IUHF
1.95MHz to 2500MHz
DC2248A-B
LTC6951IUHF-1
2.1MHz to 2700MHz
Frequently Asked Questions
1 How do I use LTC6951Wizard to design a different
setup and loop filter, simulate results and program
the LTC6951?
In the LTC6951Wizard, select Help: Menu →Help. The
help file discusses the function of all LTC6951Wizard
menus and tabs. The help file also provides a step
by step example describing how to design a different
frequency plan, design and simulate a loop filter, and
how to program the LTC6951 with these new settings.
2.Can the LTC6951Wizard control an LTC6951 on a
board other than the DC2248A?
Yes, connect the DC2026 (or DC590) SPI lines to the
SPI interface of the LTC6951. Also, the LTC6951Wizard
allows communication to the DC2248A by sensing
resistors R34 and R35 in the DC2248A schematic. If
these resistors are not present, the LTC6951Wizard
will not communicate with the LTC6951. To allow
LTC6951Wizard communication to other hardware,
install equivalent resistors in the appropriate location
on the backside of DC2026 J1 connector (or DC590B
J4 connector).
3.Does the LTC6951 have Linduino Code available?
Yes, download the LTC6951 sketch in the LTSketchbook.
To use the LTSketchbook and for instructions on how to
start using Linduino, refer to the Linduino QuickStart tab
at http://www.linear.com/solutions/linduino. This will
give programmers a head start in writing code for the
LTC6951. It is recommended to use LTC6951Wizard
to create the best possible register settings for all
conditions. These LTC6951 register settings from
LTC6951Wizard can be programmed in a lookup table.
At this point the lookup table and LTC6951 sketch can
aid in program development.
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7
DEMO MANUAL DC2248A
Typical DC2248A Requirements and Characteristics
PARAMETER
6V to 9V Power Supply
INPUT OR OUTPUT PHYSICAL LOCATION
DETAILS
Input
J15 and J16 BNC banana jacks
Default option, single supply: 6V–9V low-noise and spur-free
supply, 500mA*; Green LEDs D2, D3, and D4 illuminate
when power supplied.
OUT4+, OUT4–
Two Outputs
J1 and J2 SMA connectors**
LVDS, DC coupled, 600MHz, 750mVpk differential, 1.23V
DC offset (if powered up)*. Requires 100Ω differential
termination.
OUT3+, OUT3–
Two Outputs
J3 and J4 SMA connectors**
CML, AC coupled, 600MHz, 800mVpk differential.*
OUT0+, OUT0–
Two Outputs
J5 and J6 SMA connectors**
CML, AC coupled, 600MHz, 800mVpk differential.*
OUT1+, OUT1–
Two Outputs
J7 and J8 SMA connectors**
CML, AC coupled, 600MHz, 800mVpk differential.*
OUT2+, OUT2–
Two Outputs
J9 and J10 SMA connectors**
CML, AC coupled, 600MHz, 800mVpk differential.*
SYNC
Input
J13 SMA connector or SYNC turret Default option, 1kΩ pull-down resistor. See Tables 3 and 4,
to ensure correct option is selected.
STAT
Output
STATUS turret
Loop Bandwidth
–
Red LED D1 illuminates when STAT pin in high state.
Set by loop filter component values 344kHz*
3.3V Onboard Reference Supply
Input
JP1, Pin 1
Board modifications required for use, see Table 1.
5V LTC6951 Supply
Input
JP2, Pin 1
Board modifications required for use, see Table 1.
3.3V LTC6951 Supply
Input
JP3, Pin 1
Board modifications required for use, see Table 1.
REF+
Input
J12 SMA connector or REF+ turret
Board Modifications required for use, see Table 2.
By default an onboard reference (U2) is connected.
REF–
Input
J11 SMA connector or REF– turret
By default NOT INSTALLED.
TUNE
Output/Input
Test point
Debug Only: connected to LTC6951 TUNE pin.
V+BIAS turret
Board modifications required for use, refer to the schematic.
V+BIAS
Input
*These values are for the “ALL_CHAN_600MHz.6951set” file and the default onboard reference.
**Any unused RF output must be powered down or terminated with 50Ω, or poor spurious performance may result.
8
dc2248af
DEMO MANUAL DC2248A
PCB Layout
Top Layer
Parts List
ITEM
QTY REFERENCE
Required Circuit Components
1
1
CI1
2
0
CI2
3
1
CP
4
7
C1, C9, C13, C19, C45, C50, C51
5
1
C2
6
7
1
19
8
9
10
2
12
0
11
12
13
7
6
3
C3
C4, C6, C10, C11, C14-C17, C38-C42,
C44, C53, C58, C62, C71, C72
C5, C46
C7, C8, C12, C18, C21, C30-C35, C37
C20, C23, C36, C54, C55, C59, C60,
C63-C68
C22, C43, C49, C52, C57, C61, C70
C24-C29
C47, C48, C69
PART DESCRIPTION
MANUFACTURER/PART NUMBER
CAP., X7R, 68nF, 50V, 10%, 0603
CAP., 0805
CAP., X7R, 1200pF, 50V, 10%, 0603
CAP., X7R, 0.01µF, 16V, 10%, 0402
CAP., X7R, 820pF, 50V, 10%, 0603
MURATA, GRM188R71H683KA93D
OPT
MURATA, GRM188R71H122KA01D
AVX, 0402YC103KAT2A
MURATA, GRM188R71H821KA01
CAP., X5R, 470nF, 10V, 10%, 0402
CAP., X7R, 0.1µF, 10V, 10%, 0402
AVX, 0402ZD474KAT2A
AVX, 0402ZC104KAT2A
CAP., X7R, 1.0µF, 16V, 10%, 0603
CAP., X5R, 1.0µF, 16V, 10%, 0402
CAP., 0402
TDK, C1608X7R1C105K
AVX, 0402YD105KAT2A
OPT
CAP., X7R, 10µF, 25V, 10%, 1206
CAP., X7R, 0.01µF, 6.3V, 10%, 0201
CAP., TANT., 330µF, 10V, 10%, 7343
MURATA, GRM31CR71E106KA12L
AVX, 02016C103KAT2A
AVX, TPME337K010R0035
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9
DEMO MANUAL DC2248A
Parts List
ITEM
14
15
16
17
18
19
20
21
23
24
25
26
27
28
QTY
0
1
3
1
11
0
3
12
1
2
1
8
2
0
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
6
1
3
1
1
3
5
1
4
5
1
3
1
1
2
1
1
1
1
2
1
REFERENCE
C56
D1
D2, D3, D4
D5
E1-E11
E12
JP1, JP2, JP3
J1-J10, J12, J13, J11
J14
J15, J16
L1
L2-L9
R1, RZ
R2, R5-R7, R10, R11, R14, R16,
R18, R20, R22-R24, R53, R54
R3, R4, R8, R17, R19, R55
R9
R12, R39, R42
R13
R15
R21, R36, R47
R25, R28, R29, R30, R37
R26
R27, R31, R32, R38
R33, R34, R35, R51, R52
R40
R41, R45, R50
R43
R44
R46, R48
R49
SW1
U1
U2
U3, U4
U5
50
1
U6
51
1
U7
52
1
U8
53
1
U9
53
3
SHUNT ON JP1-JP3 PINS 1&2
DC2248A-A Required Circuit Components
1
1
2
1
U1
DC2248A-B Required Circuit Components
1
1
2
1
U1
10
PART DESCRIPTION
CAP., 1206
LED, RED, LED-ROHM-SML-010VT
LED, GREEN, LED-ROHM-SML-010FT
LED, YELLOW, LED-ROHM-SML-010YT
TURRET, TESTPOINT 0.064"
TURRET, TESTPOINT 0.064"
JMP, HD1X3, .079CC
CONN., SMA 50-OHM EDGE-LAUNCH
CONN., HEADER, 14 PIN, 2mm
JACK, BANANA
IND., 0Ω, 0805
IND, FERRITE BEAD, L-0603LS-1608
RES., CHIP, 63.4, 1%, 0603
RES., 0402
MANUFACTURER/PART NUMBER
OPT
ROHM, SML-010VTT86L
ROHM, SML-010FTT86L
ROHM, SML-010YTT86L
MILL-MAX, 2308-2-00-80-00-00-07-0
OPT
SULLINS, NRPN031PAEN-RC
EMERSON, 142-0701-851
MOLEX, 87831-1420
KEYSTONE, 575-4
VISHAY, CRCW08050000Z0EA
TAIYO YUDEN, FBMH1608HL331-T
NIC, NRC06F63R4TRF OPT
RES., CHIP, 0, 0402
RES., CHIP, 10, 1/16W, 1%, 0402
RES., CHIP, 280 1/16W, 5%, 0402
RES., CHIP, 1k, 1/16W, 1%, 0402
RES., CHIP, 330, 1/16W, 1%, 0402
RES., CHIP, 0Ω, 0603
RES., CHIP, 100Ω 1/16W, 5%, 0402
RES., CHIP, 49.9Ω, 1/16W, 1%, 0402
RES., CHIP, 200k, 1/16W, 1%, 0402
RES., CHIP, 4.99k, 1/16W, 1%, 0402
RES., CHIP, 17.8k, 1/16W, 1%, 0402
RES., CHIP, 10k, 1/16W, 1%, 0402
RES., CHIP, 619Ω 1/16W, 1%, 0402
RES., CHIP, 31.6k, 1/16W, 1%, 0402
RES., CHIP, 1M, 1/16W, 1%, 0402
RES., CHIP, 17.4k, 1/16W, 1%, 0402
SWITCH, SLIDE SPDT 30V 0.2A, SW-EG1218
I.C., QFN40UHF-5X7
I.C., 100MHz OSCILLATOR, OSC-VCXO/CVS575S
I.C., DUAL BUFFER, SC70-6
I.C., SINGLE BIT, DUAL SUPPLY, 3-STATE OUTPUT,
SOT363
I.C., SERIAL EEPROM, TSSOP8
I.C., 300mA LOW NOISE LDO REGULATOR, MS8
I.C., REG LDO ADJ 0.75A/0.25A, QFN28UFD-4X5
I.C., DUAL 2-INPUT POSITIVE-NAND GATE, US8
SHUNT, 2mm CTRS.
VISHAY, CRCW04020000Z0EA
VISHAY, CRCW04210ROFKED
NIC, NRC04J281TRF
NIC, NRC04F1001TRF
NIC, NRC04F3300TRF
NIC, NRC06Z0TRER
NIC, NRC04J101TRF
NIC, NRC04F49R9TRF
NIC, NRC04F2003TRF
NIC, NRC04F4991TRF
NIC, NRC04F1782TRF
VISHAY, CRCW040210KOFKED
NIC, NRC04F6190TRF
NIC, NRC04F3162TRF
NIC, NRC04F1004TRF
NIC, NRC04F1742TRF
E-SWITCH, EG1218
LINEAR TECH., LTC6951IUHF
CRYSTEK, CCHD-575-25-100.00
FAIRCHILD SEMI., NC7WZ17P6X
NXP SEMI., 74LVC1T45GW
MICROCHIP, 24LC025-I /ST
LINEAR TECH., LT1962EMS8
LINEAR TECH., LT3030EUFD
TI, SN74LVC2G00DCU
SAMTEC 2SN-BK-G
DC2248A2-GENERAL BOM
I.C., QFN40UHF-5X7
LINEAR TECH., LTC6951IUHF
DC2248A2-GENERAL BOM
I.C., QFN40UHF-5X7
LINEAR TECH., LTC6951IUHF-1
dc2248af
A
B
C
D
__
SYNC
SYNC
REF+
REF+
REF-
SMA
J12
EN-XO
SMA
E3
J13
E2
C33
1uF
5
3
2
1
C31
1uF
C30
1uF
R21
0
0603
4
5
6
R24
OPT
R22
OPT
R20
OPT
R25
200
R9
10
C12
1uF
C8
1uF
C7
R4
0
C36
OPT
C35
1uF
C23
OPT
C20
OPT
CI2
OPT 0805
RZ
63.4 CI1
0603 68nF 0603
5V
L9
R8
FBMH1608HL331-T 0
V+XO
5V
3.3V
4
R26
49.9
R19
0
CP
1.2nF
0603
C37
1uF
R23
OPT
C21
1uF
0603
0805
4
1. ALL RESISTORS ARE IN OHMS, 0402
2. ALL CAPACITORS ARE IN MICROFARADS, 0402.
18
C16
0.1uF
R17
0
C2
820pF
0603
3.3V
GND
V+VCO
BVCO
GND
CMA
CMB
CMC
GND
TB
TUNE
BB
V+RF
R1
63.4
32
31
30
29
28
27
26
25
24
23
22
21
L1
0 ohm
C13
0.01uF
C9
0.01uF
1uF
0603
C5
1uF
C3
470nF
C1
0.01uF
SDO
SDI
SCLK
CS
NOTE: UNLESS OTHERWISE SPECIFIED
OUT+
GND
VCC
OUT-
3.3V
FBMH1608HL331-T
L3
09-30-15
DATE
C19
0.01uF
TUNE
EN
VTUNE
U2
CCHD-575-25-100
C18
1uF
L2
FBMH1608HL331-T
C32
1uF
C22
10uF
1206
3.3V_REF
SMA
E12
J11
C34
1uF
V+OUT
REF-
PRODUCTION
CHRIS P.
APPROVED
C29
C28
C27
C26
C25
C24
0.01uF 0.01uF 0.01uF 0.01uF 0.01uF 0.01uF
0201 0201 0201 0201 0201 0201
V+OUT
2
5
20
SDO
DESCRIPTION
V+OUT
16
U1
LTC6951
V+D
REVISION HISTORY
19
SDI
35
CP
SCLK
V+REF
36
V+CP
33
17
CS
REF37
REF+
38
1
2
34
15
OUT4+
3
*
R13
1k
3
3.3V
R51
4.99K
1
SYNCON
3
D5
YELLOW
SYNCON
2
R12
280
R54
OPT
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
2
SCALE = NONE
CHRIS P.
KIM T.
APPROVALS
R18
OPT
V+BIAS
R16
OPT
V+BIAS
R14
OPT
V+BIAS
R11
OPT
V+BIAS
R10
OPT
V+BIAS
R7
OPT
V+BIAS
R6
OPT
V+BIAS
R5
OPT
V+BIAS
1Y
*
GND
ASSY
A
B
2A
2B
1B
2Y
VCC
1A
DATE:
N/A
SIZE
GND
GND
GND
GND
U1
LTC6951
LTC6951 - 1
C71
0.1uF
3.3V
1
OUT2-
OUT2+
OUT1-
OUT1+
OUT0-
OUT0+
OUT3-
OUT3+
OUT4-
OUT4+
Fout =
2.5GHz
2.7GHz
SMA
J10
SMA
J9
SMA
J8
SMA
J7
SMA
J6
SMA
J5
SMA
J4
SMA
J3
SMA
J2
SMA
J1
Wednesday, September 30, 2015
IC NO.
1
SHEET
1
ULTRALOW JITTER MULTI-OUTPUT CLOCK
SYNTHESIZER WITH INTEGRATED VCO
LTC6951IUHF
DEMO CIRCUIT 2248A
OF
3
2
REV.
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
-1
SUFFIX
L8
FBMH1608HL331-T
E4
E9
E11
E10
TECHNOLOGY
5
6
7
8
U9
SN74LVC2G00DCU
C17
0.1uF
C15
0.1uF
C14
0.1uF
C11
0.1uF
C10
0.1uF
C6
0.1uF
C4
0.1uF
C72
0.1uF
R3
0
R55
0
TITLE: SCHEMATIC
4
3
2
OFF
R53
OPT
1
R52
4.99k
3.3V
2
1
SW1
EG1218
CUSTOMER NOTICE
1
2
3
4
5
6
7
8
9
10
11
12
R2
OPT
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES.
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
APP ENG.
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
STATUS
D1
RED
R15
330
E1
V+OUT
OUT2-
OUT2+
V+OUT
OUT1-
OUT1+
V+OUT
OUT0-
OUT0+
V+OUT
OUT3-
OUT3+
STATUS
39
STAT
13
OUT4SYNC
14
V+OUT
GND
40
GND
41
REV
2
ECO
A
B
C
D
DEMO MANUAL DC2248A
Schematic Diagram
11
dc2248af
A
B
C
5
13
8 GND
3 GND
GND
1
V+ 2
5V
6
CS 4
SCK/SCL 7
MOSI/SDA 5
MISO
10
EEVCC 9
EESDA 11
EESCL 12
EEGND 14
AUX
WP
CS
SCLK
R34
4.99K
EEGND
R33
4.99K
V+DIG
6
5
7
3
2
1
R35
4.99K
SDI
SCL
SDA
WP
A2
A1
A0
24LC025-I /ST
U6
SDO
R36
0
0603
C40
0.1uF
4
NOTE: EEPROM FOR BOARD IDENTIFICATION
HD2X7-079-MOLEX
ARRAY
J14
DC590 SPI INTERFACE
4
EEPROM
8
VCC
GND
12
4
D
5
R37
100
3.3V
R31
200K
R27
200K
C42
0.1uF
R32
200K
3
2
DIR
3
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
4
5
6
3.3V
3.3V
3.3V
2
2
SCALE = NONE
CHRIS P.
KIM T.
APPROVALS
74LVC1T45GW
GND
VCC(A) VCC(B)
U5
5
2
1
4
3
GND VCC
6
1
U4
5
2
NC7WZ17P6X
4
3
GND VCC
6
NC7WZ17P6X
1
U3
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES.
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
APP ENG.
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
CUSTOMER NOTICE
3
C41
0.1uF
C39
0.1uF
R30
100
0.1uF
DATE:
N/A
SIZE
Wednesday, September 30, 2015
IC NO.
1
SHEET
2
OF
3
2
REV.
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
LTC6951IUHF
DEMO CIRCUIT 2248A
TECHNOLOGY
SDO
SDI
SCLK
CS
ULTRALOW JITTER MULTI-OUTPUT CLOCK
SYNTHESIZER WITH INTEGRATED VCO
TITLE: SCHEMATIC
R38
200K
C38
R29
100
R28
100
1
A
B
C
D
DEMO MANUAL DC2248A
Schematic Diagram
Note: The buffers shown on sheet 2 of 2 of the schematic are used to protect the LTC6951 when connected to Linduino before the LTC6951 is powered
up. There is no need for such circuitry if the SPI bus is not active before powering up the LTC6951. The EEPROM is for identification and is not needed to
program the LTC6951.
dc2248af
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
A
B
C
E5
E8
C57
10uF
1206
C58
0.1uF
C61
10uF
1206
L7
FBMH1608HL331-T
C52
10uF
1206
C62
0.1uF
C53
0.1uF
5
POWER SUPPLIES
J16
GND
JACK BANANA
JACK BANANA
6V - 9V
J15
L5
FBMH1608HL331-T
C44
0.1uF
4
OUT
ADJ
BYP
GND
IN
NC
NC
SHDN
1
2
3
3.3V
3
2
1
16
17 IN2
IN2
20
21 IN1
IN1
JP3
HD1X3-079
3.3V
NC
JP2
HD1X3-079
NC
5V
LT1962EMS8
5V
5
6
7
14
C43
10uF
1206
U7
4
3
2
1
+
C48
330uF
10V
7343
C51
0.01uF
R46
1M
R44
31.6K
C65
OPT
+
C69
330uF
10V
7343
C70
10uF
1206
3.3V
C68
OPT
R49
17.4K
R48
1M
C50
0.01uF
15
8
5V
3
EP
+
C47
330uF
10V
7343
CUSTOMER NOTICE
C46
1uF
0603
3.3V_REF
1
2
3
3
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
2
2
SCALE = NONE
CHRIS P.
KIM T.
APPROVALS
C66
OPT
C63
OPT
C59
OPT
R43
619
R42
280
R39
280
C54
OPT
V+BIAS
5V
3.3V_REF
3.3V
NC
JP1
HD1X3-079
3.3V_REF
3.3V_REF
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES.
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
APP ENG.
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
R50
10K
29
C45
0.01uF
LT3030EUFD
U8
R45
10K
R41
10K
R40
17.8K
C49
10uF
1206
10
L4
FBMH1608HL331-T
4
8
OUT2 7
OUT2
SHDN2
SHDN1
2
1 OUT1
OUT1
23
9
BYP2
BYP1
28
PWRGD2
22
ADJ2
ADJ1
27
PWRGD1
18
13
12
11
6
5
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
19
24
25
26
3
4
D
5
5V
GREEN
D4
3.3V_REF
GREEN
D3
3.3V
GREEN
D2
C56
OPT
1206
2
2
2
DATE:
N/A
SIZE
E7
E6
GND
V+REBIAS
LTC6951IUHF
DEMO CIRCUIT 2248A
Wednesday, September 30, 2015
IC NO.
1
SHEET
3
OF
3
2
REV.
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
L6
FBMH1608HL331-T
TECHNOLOGY
R47
0
0603
ULTRALOW JITTER MULTI-OUTPUT CLOCK
SYNTHESIZER WITH INTEGRATED VCO
TITLE: SCHEMATIC
C67
OPT
C64
OPT
C60
OPT
C55
OPT
1
1
1
1
A
B
C
D
DEMO MANUAL DC2248A
Schematic Diagram
dc2248af
13
DEMO MANUAL DC2248A
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions:
This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT
OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete
in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety
measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union
directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations.
If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date
of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU
OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS
FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR
ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims
arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all
appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or
agency certified (FCC, UL, CE, etc.).
No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance,
customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.
LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive.
Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and
observe good laboratory practice standards. Common sense is encouraged.
This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC application engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
14 Linear Technology Corporation
dc2248af
LT 1215 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2015