5
4
3
2
1
REVISION HISTORY
ECO
REV
__
DESCRIPTION
REBUILD WITH CHANGE
1
3.3V
APPROVED
DATE
CHRIS P.
10-02-14
J6
3.3V
D
C1
1uF
16V
0805
RZ
CP
*
CI1
*
*
0603
0603
1%
0603
C2
+ 330uF
10V
7343
J7
D
GND
CI2
*
C7
0.01uF
C6
1uF
R1
51.1
1%
2
23
24
V+CP
GNDD
26
25
CP
REF+
CMb
CMc
SDI
GNDC
SDO
TB
TUNE
MUTE
3
GND
3.3V
L1
68nH
0402HPH-68NXJL
-A
-B
-C
-D
LTC6946IUFD-1
LTC6946IUFD-2
LTC6946IUFD-3
LTC6946IUFD-4
2.24 TO 3.74 GHz
3.08 TO 4.91 GHz
3.84 TO 5.79 GHz
4.20 TO 6.39 GHz
16V
0805
17
16
15
TUNE
RF+
CUSTOMER NOTICE
CI1
CI2
CP
RZ
0.022uF
0.022uF
0.022uF
0.01uF
6800pF
6800pF
6800pF
0.01uF
2700pF
2700pF
2700pF
1500pF
453 OHMS
453 OHMS
453 OHMS
536 OHMS
4
APPROVALS
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
APP ENG.
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
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
5
B
J5
SMA-R
RF-
1. ALL RESISTORS ARE IN OHMS, 0402
ALL CAPACITORS ARE IN MICROFARADS, 0402.
*
19
18
0.1uF
C21
100pF
5%
J4
SMA-R
NOTE: UNLESS OTHERWISE SPECIFIED
VCO
C16
2.2uF
5%
C20
100pF
5%
U1
20
L2
3.3V
68nH
C22
0402HPH-68NXJL
5%
ASSY
22
21
C15
0.01uF
C19
0.01uF
JP1
A
GND
C18
1uF
16V
0805
3.3V
2
1
J9
BB
V+RF
V+D
3.3V
3.3V
CMa
SCLK
C17
0.1uF
D1
SML-010VT
RED
B
8
10V
7343
14
3.3V
GNDA
13
7
V+VCO
RF+
6
C10
+ 330uF
C
CS
12
SDI
SDO
1
R3
330
5
MUTE
STATUS
4
STAT
9
E3
CS
SCLK
*
REFO
RF-
3
SMA-R
U1
V+REFO
GNDB
2
11
1
V+REF
28
C14
0.022uF
J3
27
REF-
C13
0.1uF
REF
OUT
C9
1uF
16V
0805
C12
0.01uF
C11
1uF
3.3V
C
5V
C8 0805
1uF 16V
10
SMA-R
J8
GND
REF+
IN
5V
R4
15
29
J1
0805
3
TECHNOLOGY
KIM T.
CHRIS P.
TITLE: SCHEMATIC
ULTRALOW NOISE & SPURIOUS INTEGER-N
SYNTHESIZER WITH INTEGRATED VCO
SIZE
N/A
SCALE = NONE
2
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
DATE:
IC NO.
LTC6946IUFD FAMILY
REV.
1
DEMO CIRCUIT 1705C
Thursday, October 02, 2014
SHEET
1
1
OF
2
A
5
4
3
2
DC590 SPI INTERFACE
3.3V
D
1
U2
NC7WZ17P6X
R5
200K
1
6
3
4
R10
100
R11 100
3.3V
GND
VCC
5
C23
SCLK
0.1uF
V+DIG CS SCLK SDI SDO
1
V+ 2
5V
6
CS 4
SCK/SCL 7
MOSI/SDA 5
MISO
10
EEVCC 9
EESDA 11
EESCL 12
EEGND 14
AUX
U3
NC7WZ17P6X
R9
4.99K
C26
0.1uF
WP
EEGND
3
4
2
GND
1
VCC(A)
2
GND
3
R15
0
0603
B
6
VCC
R12
100
3.3V
5
U4
74LVC1T45GW
4
SCL
SDA
WP
A2
A1
A0
ARRAY
13
8
3
6
5
7
3
2
1
1
SDI
C
C24
0.1uF
8
U5
24LC025-I /ST
C3
0.1uF
R7
200K
VCC
R8
4.99K
R6
200K
GND
R14
4.99K
GND
GND
GND
C
2
EEPROM
J2
HD2X7-079-MOLEX
D
CS
3.3V
VCC(B)
6
DIR
5
C25
0.1uF
4
R16
100
SDO
B
R13
200K
NOTE: EEPROM FOR BOARD IDENTIFICATION
CUSTOMER NOTICE
APPROVALS
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
APP ENG.
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
A
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
5
4
3
TECHNOLOGY
KIM T.
CHRIS P.
TITLE: SCHEMATIC
A
ULTRALOW NOISE & SPURIOUS INTEGER-N
SYNTHESIZER WITH INTEGRATED VCO
SIZE
IC NO.
DATE:
REV.
LTC6946IUFD FAMILY
N/A
SCALE = NONE
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
1
DEMO CIRCUIT 1705C
Thursday, October 02, 2014
SHEET
2
1
2
OF
2