Linear Technology DC1959A Quick setup guide

1
dc1959af
DEMO MANUAL DC1959A





Frequencyreference
input,SMA
Differential
output,SMA
3.3VDCsupply,
bananajacks
5VDC
supply,
banana
jacks
Ribbon
cable
connection
toDC590
Loopfilter
components
Mute
jumper
Description
LTC6948
Ultralow Noise and Spurious Fractional-N
Synthesizer with Integrated VCO
Demonstration circuit 1959A features the LTC6948, an
Ultralow Noise and Spurious Fractional-N Synthesizer
with Integrated VCO.
There are four options of the DC1959A, one for each ver-
sion of the LTC6948. Table 1 summarizes the available
DC1959A options.
The DC1959A provides 50Ω SMA connectors for the ref-
erence frequency input fREF (REF+IN) and the differential
RF output (RF+ and RF–).
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
FracNWizard is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
A DC590 USB serial controller board is used for SPI com-
munication with the LTC6948, controlled by the supplied
FracNWizard™ software.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1959A
Figure 1. DC1959A Connections

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dc1959af
DEMO MANUAL DC1959A
Quick start proceDure
The DC1959A is easy to set up to evaluate the performance
of the LTC6948. Follow the procedure below.
The DC590 and FracNWizard application are required to
control the DC1959A through a personal computer (PC).
DC590 Configuration
Place the DC590 jumpers in the following positions (refer
to Figure 2):
JP4: EE – Must be in the EN position.
JP5: ISO – ON must be selected.
JP5: SW – ON must be selected.
JP6: VCCIO – 3.3V must be selected. This sets the SPI
port to 3.3V operation.
Connect the DC590 to one of your computer’s USB ports
with the included USB cable.
FracNWizard Installation
The FracNWizard software is used to communicate with
the LTC6948 synthesizer. It uses the DC590 to translate
between USB and SPI-compatible serial communica-
tions formats. It also includes advanced PLL design and
simulation capabilities. The following are the FracNWizard
system requirements:
nWindows Operating System: Windows XP, Windows
2003 Server, Windows Vista, Windows 7
nMicrosoft .NET 3.5 SP1 or later
nWindows Installer 3.1 or later
nLinear Technology’s DC590 hardware
Figure 2. DC590 Jumper and Connector Locations


JP6
jumpers
J4,ribbon
cable
connection
tothe
DC1959
JP5jumpers
JP4
jumper
J3,USB
connection
toPC

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dc1959af
DEMO MANUAL DC1959A
Download the FracNWizard setup file at www.linear.com/
FracNWizard.
Run the FracNWizard setup file and follow the instructions
given on the screen. The setup file will verify and/or install
Microsoft .NET and install the FracNWizard. Refer to the
Help menu for software operation.
DC1959A Configuration
1. Connecta100MHzreferencefrequencysourcetoREF+IN
(at J1) and signal analyzers to RF+ and/or RF– (at J5
and/or J4) using the SMA connectors (see Figure 1 and
the Typical DC1959A Requirements and Characteristics
table).
Be sure to terminate any unused RF output with 50Ω,
or poor spurious performance may result.
2. Choose the MUTE jumper setting:
JP1: GND/3.3V – MUTE position. Select GND to mute
the RF output, 3.3V to un-mute.
3. Connect the GND, 3.3V, and 5V banana jacks to a power
supply and apply power (see Figure 1 and the Typical
DC1959A Requirements and Characteristics table).
4. Connect the DC590 to the DC1959A with the provided
ribbon cable.
5. Run the FracNWizard application.
6. In FracNWizard, click File -> Load Settings and point to
the LTC6948-1_100MHz.fracnset file in case of evaluat-
ing the LTC6948-1, for instance, or load the appropriate
file depending on which option of the LTC6948 you are
evaluating.
The red LED on the DC1959A should turn on indicating
that the loop is locked and the output is at 907MHz.
Quick start proceDure
Figure 3. FracNWizard Screenshot

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dc1959af
DEMO MANUAL DC1959A
assembly options
typical Dc1959a reQuirements anD characteristics
Troubleshooting
If the red LED does not illuminate, follow the instructions
below:
1. Verify that you are able to communicate with the
DC1959A.Thebottom status line inFracNWizardshould
read LTC6948 and Comm Enabled as shown in Figure 3.
Refer to FracNWizard’s Troubleshoot and Help if not.
2. Verify that the 3.3V and 5V have the correct voltages
on them and that the reference frequency is applied to
the REF+IN SMA input.
If the red LED is on but you cannot detect an RF output,
make sure jumper JP1 is at the 3.3V position. Run Help ->
Troubleshoot inFracNWizard if theproblem is not resolved.
DC1959A Reconfiguration
You can redesign the frequency plan of the DC1959A using
FracNWizard. You can change the loop filter as found us-
ing FracNWizard by reinstalling the loop filter components
shown in Figure 1.
Quick start proceDure
Table 1. DC1959A Options and Frequency Ranges
ASSEMBLY VERSION PART NUMBER VCO FREQUENCY RANGE (GHz) OUTPUT DIVIDER SETTINGS
DC1959A-A LTC6948IUFD-1 2.240 to 3.740 Integers 1 through 6
DC1959A-B LTC6948IUFD-2 3.080 to 4.910 Integers 1 through 6
DC1959A-C LTC6948IUFD-3 3.840 to 5.790 Integers 1 through 6
DC1959A-D LTC6948IUFD-4 4.200 to 6.390 Integers 1 through 6
PARAMETER INPUT OR OUTPUT PHYSICAL LOCATION DETAILS
3.3V Power Supply Input J6 and J7 Banana Jacks Low-Noise and Spur-Free 3.3V, 130mA
5V Power Supply Input J8 and J9 Banana Jacks Low-Noise and Spur-Free 5V, 33mA
REF+ IN, Reference Frequency Input J1 SMA Connector Low-Noise 100MHz*, 6dBm to 10dBm into 50Ω, See Note
Below
RF+ and RF– Tw o Outputs J4 and J5 SMA Connectors** Frequency: 907MHz*, Power: 0dBm, Frequency Range:
Depends on the Version of the LTC6948 Device – Refer to
Table 1
Loop Bandwidth – Set by Loop Filter Component Values Approximately 160kHz* Depending on the DC1959A Version
*These frequencies are for the DC1959A fracnset files included with FracNWizard.
**Any unused RF output must be terminated with 50Ω, or poor spurious performance may result.
Note: A low noise 100MHz reference frequency, such as the Wenzel 501-04516D OCXO, is recommended. If using a different frequency, make sure to
update the Fref and R_DIV boxes under the System tab in FracNWizard so that Fpfd is still 50MHz. For example, if a 250MHz clock is used, Fref should be
changed to 250MHz and R_DIV to 5. Ref BST and FILT under the System tab in FracNWizard might need to be changed if the reference frequency and/or
power is different than what is recommended in the table above. More information can be found in the LTC6948 data sheet.

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dc1959af
DEMO MANUAL DC1959A
pcb layout
The top metal layer of the DC1959A is shown here as an example of good PCB layout for the LTC6948.

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dc1959af
DEMO MANUAL DC1959A
parts list
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 0 CI2 CAP., 0805 OPT
2 5 C1, C8, C9, C15, C18 CAP., X7R, 1.0µF, 16V, 10%, 0603 TDK, C1608X7R1C105K
3 2 C2, C10 CAP., TANT., 330µF, 10V, 10%, 7343 AVX, TPME337K010R0035
4 9 C3, C7, C17, C22-C27 CAP., X7R, 0.1µF, 10V, 10%, 0402 TDK, C1005X7R1A104K
5 2 C6, C11 CAP., X5R, 1.0µF, 16V, 10%, 0402 TDK, C1005X5R1C105K
6 3 C12, C13, C19 CAP., X7R, 0.01µF, 16V, 10%, 0402 AVX, 0402YC103KAT2A
7 1 C16 CAP., X5R, 2.2µF, 16V, 10%, 0603 TDK, C1608X5R1C225K
8 0 C2_F2, C28 CAP., 0603 OPT
9 2 C20, C21 CAP., X7R, 100pF, 50V, 10%, 0402 AVX, 04025C101KAT2A
10 1 D1 LED, RED PANASONIC, LN1251C-TR
11 1 E3 TURRET, TESTPOINT, 2501 MILL-MAX, 2501-2-00-80-00-00-07-0
12 1 JP1 HEADERS, 3 PINS 2mm CTRS. SAMTEC, TMM-103-02-L-S
13 3 J1, J4, J5 CON., SMA 50Ω EDGE-LAUNCH E.F. JOHNSON, 142-0701-851
14 1 J2 CON., HEADER, 14 PIN, 2mm MOLEX, 87831-1420
15 4 J6, J7, J8, J9 JACK, BANANA KEYSTONE, 575-4
16 2 L1, L2 IND., 68nH 5%, 0402 COILCRAFT, 0402HPH-68NXJLW
17 1 L1_F1 IND., 10µH, 0805 TDK, MLF2012E100K
18 0 L1_F2 IND., 0805 OPT
19 1 R1 RES., CHIP, 51.1Ω, 1/16W, 1%, 0402 NIC, NRC04F51R1TRF
20 0 R1_F2 RES., 0603 OPT
21 4 R2, R18, R19, R20 RES., CHIP, 0Ω, 0402 NIC, NRC04Z0TRF
22 1 R3 RES., CHIP, 330Ω, 1/16W, 1%, 0402 NIC, NRC04F3300TRF
23 1 R4 RES., CHIP, 15Ω, 1/16W, 1%, 0402 NIC, NRC04F15R0TRF
24 4 R5, R6, R7, R13 RES., CHIP, 200k, 1/16W, 1%, 0402 NIC, NRC04F2003TRF
25 3 R8, R9, R14 RES., CHIP, 4.99k, 1/16W, 1%, 0402 NIC, NRC04F4991TRF
26 3 R10, R11, R12 RES., CHIP, 100Ω 1/16W, 5%, 0402 NIC, NRC04J101TRF
27 1 R15 RES., CHIP, 0Ω, 0603 NIC, NRC06Z0TRF
28 2 U2, U3 I.C., DUAL BUFFER, SC70-6 FAIRCHILD SEMI., NC7WZ17P6X
29 1 U4 I.C., DUAL TRANSCEIVER, SOT363 NXP, 74LVC1T45GW+125
30 1 U5 I.C., SERIAL EEPROM, TSSOP8 MICROCHIP, 24LC025-I /ST
31 1 SHUNT ON JP1 SHUNT, 2mm CTRS. SAMTEC 2SN-BK-G

7
dc1959af
DEMO MANUAL DC1959A
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
DC1959A-A Required Circuit Components
1 1 DC1959A GENERAL BOM
2 1 C2_F1 CAP., C0G, 2.4nF, 50V, 5%, 0603 MURATA, GRM1885C1H242JA01D
3 1 CI1 CAP., X7R, 82nF, 50V, 10%, 0603 MURATA, GRM188R71H823KA93D
4 1 CP CAP., C0G, 3.6nF, 50V, 5%, 0603 MURATA, GRM1885C1H362JA01D
5 2 R1_F1, RZ RES., CHIP, 57.6Ω, 1/16W, 1%, 0603 NIC, NRC06F57R6TRF
6 1 U1 I.C. SYNTHESIZER, QFN28UFD-4X5 LINEAR TECH., LTC6948IUFD-1
DC1959A-B Required Circuit Components
1 1 DC1959A GENERAL BOM
2 1 C2_F1 CAP., C0G, 2nF, 50V, 5%, 0603 MURATA, GRM1885C1H202JA01D
3 1 CI1 CAP., X7R, 68nF, 50V, 10%, 0603 MURATA, GRM188R71H683KA93D
4 1 CP CAP., C0G, 3nF, 50V, 5%, 0603 MURATA, GRM1885C1H302JA01D
5 2 R1_F1, RZ RES., CHIP, 63.4Ω, 1/16W, 1%, 0603 NIC, NRC06F63R4TRF
6 1 U1 I.C. SYNTHESIZER, QFN28UFD-4X5 LINEAR TECH., LTC6948IUFD-2
DC1959A-C Required Circuit Components
1 1 DC1959A GENERAL BOM
2 1 C2_F1 CAP., X7R, 1.8nF, 50V, 10%, 0603 MURATA, GRM188R71H182KA01D
3 1 CI1 CAP., X7R, 56nF, 50V, 10%, 0603 MURATA, GRM188R71H563KA93D
4 1 CP CAP., C0G, 2.4nF, 50V, 5%, 0603 MURATA, GRM1885C1H242JA01D
5 2 R1_F1, RZ RES., CHIP, 75Ω, 1/16W, 5%, 0603 VISHAY, CRCW060375R0JNEA
6 1 U1 I.C. SYNTHESIZER, QFN28UFD-4X5 LINEAR TECH., LTC6948IUFD-3
DC1959A-D Required Circuit Components
1 1 DC1959A GENERAL BOM
2 1 C2_F1 CAP., C0G, 1.6nF, 50V, 5%, 0603 MURATA, GRM1885C1H162JA01D
3 1 CI1 CAP., X7R, 56nF, 50V, 10%, 0603 MURATA, GRM188R71H563KA93D
4 1 CP CAP., C0G, 2.4nF, 50V, 5%, 0603 MURATA, GRM1885C1H242JA01D
5 2 R1_F1, RZ RES., CHIP, 76.8Ω, 1/16W, 1%, 0603 NIC, NRC06F76R8TRF
6 1 U1 I.C. SYNTHESIZER, QFN28UFD-4X5 LINEAR TECH., LTC6948IUFD-4
parts list

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dc1959af
DEMO MANUAL DC1959A
schematic Diagram
5 5
4 4
3 3
2 2
1 1
D D C C B B A A
VCO
2.24 TO 3.74 GHz 3.08 TO 4.91 GHz 3.84 TO 5.79 GHz
ASSY U1
*A LTC6948IUFD-1
LTC6948IUFD-2 LTC6948IUFD-3
NOTE: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS ARE IN OHMS, 0402 2. ALL CAPACITORS ARE IN MICROFARADS, 0402
LTC6948IUFD-4 4.20 TO 6.39 GHz
B C D
CI1 R1_F1, RZC2_F1 CP
3.6nF82nF 57.62.4nF 3nF68nF 63.42nF 2.4nF56nF 751.8nF
56nF 76.81.6nF 2.4nF
3.3V
5V
3.3V
3.3V
3.3V
3.3V
3.3V
3.3V
5V
CS
SCLK
SDO
SDI
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: [phone]
Milpitas, CA 95035 Phone: [phone] McCarthy Blvd. LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
2
DEMO CIRCUIT 1959A
01/27/2014, 12:05 PM
12
ULTRALOW NOISE & SPURIOUS FRACTIONAL-N
N/A LTC6948IUFD-1/-2/-3/-4
KIM T.
MICHEL A.
SYNTHESIZER WITH INTEGRATED VCO
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: [phone]
Milpitas, CA 95035 Phone: [phone] McCarthy Blvd. LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
2
DEMO CIRCUIT 1959A
01/27/2014, 12:05 PM
12
ULTRALOW NOISE & SPURIOUS FRACTIONAL-N
N/A LTC6948IUFD-1/-2/-3/-4
KIM T.
MICHEL A.
SYNTHESIZER WITH INTEGRATED VCO
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: [phone]
Milpitas, CA 95035 Phone: [phone] McCarthy Blvd. LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
2
DEMO CIRCUIT 1959A
01/27/2014, 12:05 PM
12
ULTRALOW NOISE & SPURIOUS FRACTIONAL-N
N/A LTC6948IUFD-1/-2/-3/-4
KIM T.
MICHEL A.
SYNTHESIZER WITH INTEGRATED VCO
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
MICHEL A.
PRODUCTION
201-27-14
__
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
MICHEL A.
PRODUCTION
201-27-14
__
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
MICHEL A.
PRODUCTION
201-27-14
__
R2
0
R2
0
R19 0 R19 0
C6
1uF
C6
1uF
L2
68nH
0402HPH-68NXJL
L2
68nH
0402HPH-68NXJL
C12
0.01uF
C12
0.01uF
C8 1uF 0603 C8 1uF 0603
R18
0
R18
0
JP1
GND
3.3V
MUTE
JP1
GND
3.3V
MUTE
1 3 2
C2_F1
*
0603
C2_F1
*
0603
C20
100pF
C20
100pF
J1
SMA-R
REF+
IN
J1
SMA-R
REF+
IN
C27
0.1uF
C27
0.1uF
+
C2 330uF 10V 7343
+
C2 330uF 10V 7343
C9 1uF 0603 C9 1uF 0603
R1_F1
*
0603
R1_F1
*
0603
C16 2.2uF
0603
C16 2.2uF
0603
L1
68nH
0402HPH-68NXJL
L1
68nH
0402HPH-68NXJL
J5 SMA-R
RF+
J5 SMA-R
RF+
J7
GND
J7
GND
C21
100pF
C21
100pF
R3 330 R3 330
J9
GND
J9
GND
J8
5V
J8
5V
C22
0.1uF
C22
0.1uF
TUNETUNE
J6
3.3V
J6
3.3V
R20
0
R20
0
E3
STATUS
E3
STATUS
R4 15 R4 15 C19 0.01uF C19 0.01uF
C28
OPT
0603
C28
OPT
0603
L1_F2 OPT 0805 L1_F2 OPT 0805 R1_F2 OPT 0603 R1_F2 OPT 0603
C7
0.1uF
C7
0.1uF
CI2
OPT
0805
CI2
OPT
0805
C2_F2
OPT 0603
C2_F2
OPT 0603
CP
*
0603
CP
*
0603
C15 1uF 0603 C15 1uF 0603
J4
SMA-R
RF-
J4
SMA-R
RF-
CI1
*
0603
CI1
*
0603
R1 51.1 R1 51.1
C17 0.1uF C17 0.1uF
C13
0.01uF
C13
0.01uF
+
C10 330uF 10V 7343
+
C10 330uF 10V 7343
D1 LN1251C D1 LN1251C
2 1
C11
1uF
C11
1uF
U1 *
QFN28UFD-4X5
U1 *
QFN28UFD-4X5
STAT
2
TUNE 15
CS
3
MUTE
9
SDI
5
V+D
8
LDO
7
RF+
12
RF-
11
GNDA
10
SCLK
4
TB 16
GNDB 17
V+RF
13
REF+
1
BB
14
SDO
6
CMC 18 CMB 19 CMA 20
GNDC 21
BVCO 22
V+VCO 23
GNDD 24
V+CP 25
CP 26
V+REF 27
REF- 28
GND 29
C18 1uF 0603 C18 1uF 0603
L1_F1
10uH
0805
L1_F1
10uH
0805
RZ * 0603 RZ * 0603
C1 1uF 0603 C1 1uF 0603

9
dc1959af
DEMO MANUAL DC1959A
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 representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
schematic Diagram
5 5
4 4
3 3
2 2
1 1
D D C C B B A A
NOTE: EEPROM FOR BOARD IDENTIFICATION
DC590 SPI INTERFACE
3.3V
3.3V
3.3V
3.3V
CS
SCLK
SDI
SDO
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: [phone]
Milpitas, CA 95035 Phone: [phone] McCarthy Blvd. LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
2
DEMO CIRCUIT 1959A
01/27/2014, 11:57 AM
22
ULTRALOW NOISE & SPURIOUS FRACTIONAL-N
N/A LTC6948IUFD-1/-2/-3/-4
KIM T.
MICHEL A.
SYNTHESIZER WITH INTEGRATED VCO
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: [phone]
Milpitas, CA 95035 Phone: [phone] McCarthy Blvd. LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
2
DEMO CIRCUIT 1959A
01/27/2014, 11:57 AM
22
ULTRALOW NOISE & SPURIOUS FRACTIONAL-N
N/A LTC6948IUFD-1/-2/-3/-4
KIM T.
MICHEL A.
SYNTHESIZER WITH INTEGRATED VCO
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: [phone]
Milpitas, CA 95035 Phone: [phone] McCarthy Blvd. LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
2
DEMO CIRCUIT 1959A
01/27/2014, 11:57 AM
22
ULTRALOW NOISE & SPURIOUS FRACTIONAL-N
N/A LTC6948IUFD-1/-2/-3/-4
KIM T.
MICHEL A.
SYNTHESIZER WITH INTEGRATED VCO
R11 100R11 100
C23 0.1uFC23 0.1uF
R12
100
R12
100
C3
0.1uF
C3
0.1uF
CSCS SDOSDO
R7
200K
R7
200K
V+DIGV+DIG
R10
100
R10
100
R15
0
0603
R15
0
0603
R6
200K
R6
200K
J2
HD2X7-079-MOLEX
J2
HD2X7-079-MOLEX
MOSI/SDA 7
EESDA 9
V+ 1
5V 2
CS 6
SCK/SCL 4
EEVCC 10
MISO 5
EESCL 11
EEGND 12
AUX 14
GND
3
GND
13
GND
8
R5
200K
R5
200K
EEPROM
ARRAY
U5
24LC025-I /ST
EEPROM
ARRAY
U5
24LC025-I /ST
SDA
5
VCC 8
A0
1A1 2A2 3
GND
4
WP
7
SCL
6
WPWP
C24 0.1uF C24 0.1uF
R13
200K
R13
200K
GND
DIR
VCC(A) VCC(B)
U4 74LVC1T45GW
GND
DIR
VCC(A) VCC(B)
U4 74LVC1T45GW
1 6
43 52
EEGNDEEGND
R8
4.99K
R8
4.99K
C25
0.1uF
C25
0.1uF
SDISDI
R9
4.99K
R9
4.99K
GND VCC
U3
NC7WZ17P6X
GND VCC
U3
NC7WZ17P6X
1 6
43 52
R14
4.99K
R14
4.99K
C26
0.1uF
C26
0.1uF
GND VCC
U2 NC7WZ17P6X
GND VCC
U2 NC7WZ17P6X
1 6
43 52
SCLKSCLK
Note: The buffers shown on sheet 2 of 2 of the schematic are used to protect the LTC6948 when connected to the DC590 before the LTC6948 is powered up. There is no
need for such circuitry if the SPI bus is not active before powering up the LTC6948. The EEPROM is for identification and is not needed to program the LTC6948.

10
dc1959af
DEMO MANUAL DC1959A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2014
LT 0414 • PRINTED IN USA
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LT C ) 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 LT C 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 LT C 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. LT C assumes no liability for applications assistance,
customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.
LT C 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 LT C applica-
tion engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation