8
dc1649afa
DEMO MANUAL DC1649A
SCHEMATIC DIAGRAM
Note:
The buffers shown on sheet 2 of 2 of the schematic are used to
protect the LTC6945 when communicating to it starts before powering it
up. There is no need for such circuitry if the SPI bus is not active before
powering up the LTC6945. The EEPROM is for identification and is not
needed to program the LTC6945.
A
A
B
B
C
C
D
D
E
E
4
4
3
3
2
2
1
1
DC590B SPI INTERFACE
0603
NOTE: EEPROM FOR BOARD IDENTIFICATION
3.3V
3.3V
3.3V
3.3V
CS
SCLK
SDI
SDO
SIZE
DATE:
.
V
E
R
.
O
N
CI
SHEET
OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY
Fax: (408)434-0507
Milpitas, CA 95035 Phone: (408)432-1900
1630 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
4
11/01/2011, 02:27 PM
22
ULTRALOW NOISE AND SPURIOUS INTEGER-N SYNTHESIZER
KIM T.
MICHEL A.
N/A
LTC6945IUFD
DEMO CIRCUIT 1649A
SIZE
DATE:
.
V
E
R
.
O
N
CI
SHEET
OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY
Fax: (408)434-0507
Milpitas, CA 95035 Phone: (408)432-1900
1630 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
4
11/01/2011, 02:27 PM
22
ULTRALOW NOISE AND SPURIOUS INTEGER-N SYNTHESIZER
KIM T.
MICHEL A.
N/A
LTC6945IUFD
DEMO CIRCUIT 1649A
SIZE
DATE:
.
V
E
R
.
O
N
CI
SHEET
OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY
Fax: (408)434-0507
Milpitas, CA 95035 Phone: (408)432-1900
1630 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
4
11/01/2011, 02:27 PM
22
ULTRALOW NOISE AND SPURIOUS INTEGER-N SYNTHESIZER
KIM T.
MICHEL A.
N/A
LTC6945IUFD
DEMO CIRCUIT 1649A
C44 0.1uF
C44 0.1uF
SDOSDO
R8 200K
R8 200K
R26 4.99K
R26 4.99K
EEPROM
ARRAY
U8
24LC025-I /ST
EEPROM
ARRAY
U8
24LC025-I /ST
SDA
5
VCC
8
A0
1
A1
2
A2
3
GND
4
WP
7
SCL
6
SCLKSCLK
GND
V
CC
U5 NC7WZ17P6X
GND
V
CC
U5 NC7WZ17P6X
1
6
4
3
5
2
WPWP
R7 200K
R7 200K
R27 4.99K
R27 4.99K
GND
DIR
VCC(A)
VCC(B)
U7 74LVC1T45GW
GND
DIR
VCC(A)
VCC(B)
U7 74LVC1T45GW
1
6
4
3
5
2
R22
100
R22
100
SDISDI
V+DIGV+DIG
CSCS
C39 0.1uF
C39 0.1uF
C41
0.1uF
C41
0.1uF
R9 0
R9 0
R25 4.99K
R25 4.99K
GND
V
CC
U6 NC7WZ17P6X
GND
V
CC
U6 NC7WZ17P6X
1
6
4
3
5
2
R21
100
R21
100
C36 0.1uF
C36 0.1uF
EEGNDEEGND
C43 0.1uF
C43 0.1uF
R12 100
R12 100
R18 200K
R18 200K
J8
HD2X7-079-MOLEX
J8
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
R19 200K
R19 200K
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