Linear Technology DC1765A Quick setup guide

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dc1765af
DEMO MANUAL DC1765A
Description
LTC6957-1/LTC6957-2
Low Phase Noise, Dual LVPECL or LVDS
Output Buffer/Driver/Logic Converter
Demonstration Circuit 1765A features the LT C
®
6957-1/
LTC6957-2, a low phase noise, dual LVPECL or LVDS
output buffer/driver/logic converter.
The DC1765A provides 0.5" spaced SMA connectors for
the differential inputs and outputs. The inputs are termi-
nated to on-board 50Ω resistors. The LVPECL outputs
of the DC1765A-A are individually biased through 130Ω
resistors to ground and then AC-coupled. The transmis-
sion lines are 50Ω, making the outputs suitable to drive
50Ω input impedance instruments. The LVDS outputs
of the DC1765A-B are terminated with 100Ω differential
and are DC-coupled. The DC1765A allows the user to
take advantage of the shutdown and bandwidth selection
features of the LTC6957. The DC1765A can operate with
a single-ended or differential sine wave or square-wave
input signal. Supply the DC1765A with 3.3V and it is
ready to function. The DC1765A offers extra component
population options to make it compatible with different
logic signal types.
Design files for this circuit board are available at
http://www.linear.com/demo
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
Figure 1. DC1765A Inputs and Outputs

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DEMO MANUAL DC1765A
Quick start proceDure
The DC1765A is very straightforward to operate. Refer to
Figure 1 for the following discussion.
DC1765A Configuration
1. Applyalow-noise and low-spurious3.3Vsupplybetween
the V+ (E1) and GND (E2) turrets.
2. Connect a low phase-noise (or jitter) single-ended or
differential input signal to IN+ (J1) and/or IN– (J2)
SMA connectors. Refer to the LTC6957 data sheet for
appropriate input signal types and levels.
3. Connect either of the outputs (OUT1, J3 and J4 or OUT2,
J5 and J6) to a high-speed scope, spectrum analyzer or
a signal analyzer to start the evaluation of the LTC6957.
4. Configure the input bandwidth of the LTC6957 with the
use of FILTA (JP1) and FILTB (JP2) jumpers. Follow the
instructions given in the LTC6957 data sheet to choose
the correct bandwidth given an input signal.
5. Shutdown an unused output by using jumper SD1 (JP3)
to shutdown OUT1 or jumper SD2 (JP4) to shutdown
OUT2.
DC1765A Reconfiguration
The DC1765A is flexible and allows the connectivity of a
variety of input and output signal types. The DC1765A is
configured as shown in the schematic diagram. However,
the DC1765A allows the installation of different input and
output configurations to adapt to a variety of logic sig-
nals. Refer to the Applications Information section of the
LTC6957 data sheet for all possible connectivity options
that can be implemented by modifying the DC1765A.

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dc1765af
DEMO MANUAL DC1765A
assembly options
Table 1. DC1765A Assembly Options
ASSEMBLY VERSION PART NUMBER OUTPUT TYPE
DC1765A-A LTC6957HMS-1 LVPECL
DC1765A-B LTC6957HMS-2 LVDS
layout top layer
The top metal layer of the DC1765A is shown here as an example of good PCB layout for the LTC6957-1/LTC6957-2.

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DEMO MANUAL DC1765A
parts list
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
DC1765A General BOM
1 2 C6, C8 CAP., X7R, 0.01µF 50V 10%, 0603 NIC, NMC0603X7R103K50TRP
2 1 C13 CAP., X7R, 0.1µF 50V 10%, 0603 TDK, C1608X7R1H104K
3 1 C14 CAP., X5R, 1µF 25V 10%, 0603 TDK, C1608X5R1E105K
4 1 C16 CAP., TANT, 22µF 10V, 3528 AVX, TPSB226K010R0400
5 2 E1, E2 TESTPOINT, TURRET 0.094" MILLMAX, 2501-2-00-80-00-00-07-0
6 4 JP1, JP2, JP3, JP4 HEADER 1×3 079 SAMTEC, TMM-103-02-L-S
7 6 J1, J2, J3, J4, J5, J6 CONN., SMA 50Ω EDGE-LAUNCH E.F. JOHNSON, 142-0701-851
8 0 R6, R11, R14 RES., OPT 0603 OPT
9 2 R7, R15 RES., CHIP, 49.9Ω 1% 0603 VISHAY, CRCW060349R9FKEA
10 4 R16, R17, R18, R19 RES., CHIP, 330k 1% 0603 VISHAY, CRCW0603330KFKEA
11 4 SHUNTS FOR JP1-JP4 SHUNT, .079" CENTER SAMTEC, 2SN-BK-G
12 4 STAND-OFF, NYLON 0.500 KEYSTONE, 8833 (SNAP ON)
DC1765A-A
1 1 DC1765A GENERAL BOM DC1765A
2 4 Z1, Z2, Z3, Z4 CAP., X7R, 0.01µF 50V, 0603 NIC, NMC0603X7R103K50TRP
3 4 R1, R2, R3, R4 RES., CHIP, 130Ω, 0603 VISHAY, CRCW0603130RFKEA
4 0 R20, R21 RES., 0603 OPT
5 1 U1 IC, LTC6957HMS-1, MS12 LINEAR TECH., LTC6957HMS-1
DC1765A-B
1 1 DC1765A GENERAL BOM DC1765A
2 4 Z1, Z2, Z3, Z4 RES., CHIP, 0Ω, 0603 VISHAY, CRCW06030000Z0EA
3 0 R1, R2, R3, R4 RES., 0603 OPT
4 2 R20, R21 RES., CHIP, 100Ω 5%, 0603 VISHAY, CRCW0603100RJNEA
5 1 U1 IC, LTC6957HMS-2, MS12 LINEAR TECH., LTC6957HMS-2

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DEMO MANUAL DC1765A
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: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS AND CAPACITORS ARE 0603.
GND
ASSY
LTC6957HMS-1
U1
-A
LTC6957HMS-2-B
H
L
H
L
H
L
H
L
R1-R4
130 OHM
OPT
Z1-Z4
0.01uF
0 OHM
3.15V - 3.45V
*
V+
*R20-R21
OPT
100 OHM
LVPECL
LVDS
OUT1+ OUT1- OUT2- OUT2+
V+
V+
V+ V+
V+
V+ V+
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
MICHEL A.PRODUCTION3 08-16-12
__
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
MICHEL A.PRODUCTION3 08-16-12
__
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
MICHEL A.PRODUCTION3 08-16-12
__
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
3
08/16/2012, 06:45 PM
11
LOW PHASE NOISE, DUAL LVPECL OR LVDS OUTPUT
KIM T.
MICHEL A.
N/A
LTC6957HMS-1 / -2
DEMO CIRCUIT 1765A
BUFFER / DRIVER / LOGIC CONVERTER
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
3
08/16/2012, 06:45 PM
11
LOW PHASE NOISE, DUAL LVPECL OR LVDS OUTPUT
KIM T.
MICHEL A.
N/A
LTC6957HMS-1 / -2
DEMO CIRCUIT 1765A
BUFFER / DRIVER / LOGIC CONVERTER
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
3
08/16/2012, 06:45 PM
11
LOW PHASE NOISE, DUAL LVPECL OR LVDS OUTPUT
KIM T.
MICHEL A.
N/A
LTC6957HMS-1 / -2
DEMO CIRCUIT 1765A
BUFFER / DRIVER / LOGIC CONVERTER
J4
SMA-R
OUT1-
J4
SMA-R
OUT1-
JP3 SD1 JP3 SD1
1 3 2
J1
SMA-R
IN+
J1
SMA-R
IN+
R1 * R1 *
U1U1
GND
5
IN-
4
IN+
3
V+
2
FILTA
1
OUT1- 10 OUT2- 9
OUT2+ 8
SD2 7
FILTB
6
OUT1+ 11
SD1 12
R4 * R4 *
JP1
FILTA
JP1
FILTA
1 3 2
R2 * R2 *
R20 * R20 *
Z1
*
Z1
*
R6 OPT R6 OPT
C13 0.1uF C13 0.1uF
C14 1uF C14 1uF
C8
0.01uF
C8
0.01uF
+
C16 22uF
3528 10V
+
C16 22uF
3528 10V
R15 49.9 R15 49.9
R14 OPT R14 OPT
E2E2
R3 * R3 *
J3
SMA-R
OUT1+
J3
SMA-R
OUT1+
R11 OPT R11 OPT
R19 330k R19 330k
R7 49.9 R7 49.9
C6
0.01uF
C6
0.01uF
JP2
FILTB
JP2
FILTB
1 3 2
R18 330k R18 330k
R17 330k R17 330k
E1E1
R21 * R21 *
Z2
*
Z2
*
J2
SMA-R
IN-
J2
SMA-R
IN-
Z3
*
Z3
*
J6
SMA-R
OUT2+
J6
SMA-R
OUT2+
JP4 SD2 JP4 SD2
1 3 2
J5
SMA-R
OUT2-
J5
SMA-R
OUT2-
R16 330k R16 330k
Z4
*
Z4
*

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dc1765af
DEMO MANUAL DC1765A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2013
LT 0213 • 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
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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
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agency certified (FCC, UL, CE, etc.).
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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-
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