Linear Technology LTC6417 User manual

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DEMO MANUAL DC1660B
Description
LTC6417
1.6GHz Low Noise Differential
16-Bit ADC Buffer
Demonstration circuit 1660B features the LTC
®
6417 dif-
ferential 16-bit ADC buffer. The demo board incorporates a
variety of passive components to allow for direct connec-
tion to a two-port network analyzer or other single-ended
50Ω test system.
The demo board is easily configured to control common-
mode voltage VCM, clamp voltage CLHI, power adjust
PWRADJ,andSHUTDOWNpins.OthersimplePCBmodifi-
cationscanaccommodate differential input/output signals.
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.
Quick start proceDure
DC1660B is easy to set up to evaluate the performance of
the LTC6417. Refer to Figure 1 for proper measurement
equipment setup and follow the procedure below:
1. Connect SMA cables to IN+and OUT+ports.
2. Apply 5.0V between V+and GND turrets.
Tie PWRADJ (TURRET E4) to V+. Limit supply current
to approximately 150mA.
3. VCM, CLHI and SHDN turrets may be left floating.
This procedure contains a critical sequence. The user
must apply supply voltage before applying signal power
to the inputs or forcing a voltage to any other turrets. The
user must also remove the signal from the input ports
and voltages on any other turret before turning down
the supply voltage. This proper sequence will prevent
excessive current through the ESD diodes from any pin
to the positive supply V+.Table 1 shows the function of
each SMA connector on the board. Only J1, J3 and J5
are used in the default configuration. J2 and J4 provide
flexibility for differential input/output signals.
Table 1. DC1660B SMA Connectors
CONNECTOR FUNCTION
J1 (IN+) Differential input connected to input balun for single-
ended operation. Drive from a 50Ω signal source.
No external termination needed.
J2 (IN–) Differential Input. Not connected by default. Remove
capacitor C12 to drive the input balun differentially.
J3 (OUT+) Differential output connected to balun for single-ended
operation. Connect to a 50Ω network/spectrum
analyzer input.
J4 (OUT–) Differential Output. Not connected by default. Remove
capacitor C11 to drive the input balun differentially.
J5 (OR) Overrange Output. Connect to oscilloscope for
monitoring the output signal.
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DEMO MANUAL DC1660B
Figure 1. Proper Measurement Equipment Setup
Quick start proceDure
DC1660B F01
Signal
Generator
Spectrum
Analyzer
DC Power Supply
GND V+
V+ = 4.75V to 5.25V
T1
IMPEDANCE
RATIO
R2 = R6 =
VALUE (Ω)
POWER
GAIN (dB)
MABA-007159-000000 1:1 24.9 0
TMC4-19+ 1:4 100
1:8 200
3
TC8-1G2+ 4.5
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DEMO MANUAL DC1660B
applications information
Input
Demo board DC1660B’s single-ended input is AC-coupled
at port J1. The balun transformer T1 has a 1:4 impedance
ratio and it is matched to 50Ω at its input, when resistors
R2 and R6 are equal to 100Ω.
To drive the inputs differentially, remove capacitor C12.
To DC-couple the inputs, replace DC blocking capacitors
C7 and C10 with 0Ω resistors.
Output
The board’s output transformer T2 has a 1:1 impedance
ratio. T2 converts the LTC6417’s differential output signals
to a single-ended output.
To match T2 to 50Ω, change output series resistors R1
and R3 to 23.7Ω each.
For differential outputs, remove capacitor C11.
To DC-couple the outputs, replace DC blocking capacitors
C5 and C9 with a 0Ω resistor.
Additional Information
The demo board DC1660B is ready to use out of the box.
The demo board is shipped with the default configuration
as single ended input and output. However, it has features
that you can access by adding, removing or changing
components on the board. Refer to LTC6417 data sheet
for more information.
Output Common Mode Adjustment
Turret E1, labeled VCM, controls the output common mode
voltage of the LTC6417.
This function can be used to set the DC output voltage for
optimum system performance.
In the default configuration, C5 and C9 block the DC out-
put voltages. Replace these capacitors with 0Ω jumpers,
and the transmission-line type transformer T2 will couple
the DC voltages to the output port J3. If turret E1 is left
floating, the LTC6417 will self-bias the VCM pin to 1.25V
on a 5.0V supply. The VCM pin has a voltage range from
0.85V to 1.65V.
CLHI
Turret E5, labeled CLHI, controls the high side clamping
voltage of the LTC6417. If turret E5 is left floating, the
LTC6417 will self-bias the CLHI pin to 2.5V on a 5.0V
supply. The internal low side clamping voltage and CLHI
is symmetric with respect to VCM. When CLHI = 2.5V, and
VCM = 1.25V, internal low side clamp will be 0V. Either
output will be limited by these clamp voltages. See the
LTC6417 data sheet for more information.
PWRADJ
Turret E4, labeled PWRADJ, scales the supply current of
the LTC6417. If turret E4 is left floating, the LTC6417 will
self-bias the PWRADJ pin to 1.6V on a 5.0V supply with
a supply current of approximately 115mA.
Shutdown
Turret E7, labeled SHUTDOWN, puts the LTC6417 into
sleep mode when pulled high, significantly reducing
supply current (~25mA). If turret E7 is left floating, the
LTC6417 will pull the SHUTDOWN pin to GND potential
and remain enabled.
Schematic Note
The schematic included at the end of this Quick Start Guide
includes approximate power gains at various points along
DC1660B’s signal chain. The power gains (PG1 – PG4)
assume single-ended 50Ω test system and the LTC6417
is operating in a small-signal region. If the output load is
a high-impedance load, the power gains PG3 – PG4 will
vary from the schematic.
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DEMO MANUAL DC1660B
parts list
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
1 15 C1, C3, C4, C5, C7, C9, C10,
C13-C15, C17, C19-C21, C24
CAP., X5R, 0.1µF, 16V, 10% 0402 AVX, 0402YD104KAT2A
2 4 C2, C16, C18, C22 CAP., X7R, 680pF, 50V, 10% 0402 AVX, 04025C681KAT2A
3 2 C11, C12 CAP., X7R, 0.1µF, 25V, 20% 0603 AVX, 06033C104MAT2A
4 0 C6, C8, C23 CAP., OPT 0603 (OPT)
5 6 E1, E2, E3, E4, E5, E7 TESTPOINT TURRET, .061" PBF MILL-MAX, 2308-2-00-80-00-00-07-0
6 5 J1, J2, J3, J4, J5 CON., SMA 50Ω EDGE-LAUNCH E.F. JOHNSON, 142-0701-851/132357
7 2 R2, R6 RES., CHIP, 100Ω, 1/16W, 1% 0402 VISHAY CRCW0402100RFKED
8 4 R1, R3, R4, R5 RES., CHIP, 0Ω, 1/16W, 1% 0402 VISHAY, CRCW04020000Z0ED
9 0 R7, R8 RES., CHIP OPT 0402 (OPT)
10 1 T1 TRANSFORMER, TCM4-19+ SM-22 MINI-CIRCUITS TCM4-19+
11 1 T2 TRANSFORMER, ETC1-1-13, SM-22 M/A-COM, MABA-007159-000000 (PBF)
12 1 U1 I.C. LTC6417CUDC UDC 20 PIN (3×4) LINEAR, LTC6417CUDC#PBF
13 1 FAB, PRINTED CIRCUIT BOARD DEMO CIRCUIT 1660B
14 2 STENCILS TOP AND BOTTOM STENCIL DC1660B
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DEMO MANUAL DC1660B
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
DD C C B B A A
NOTE: UNLESS OTHERWISE SPECIFIED
1. ALL RESISTORS AND CAPACITORS ARE 0402
DEMO CIRCUIT 1660B
IN-
GND
V+ 4.75V - 5.25V
PWRADJ
CL HI
SHUT DOWN VCM
IN+
OUT+
OUT-
OR
INPUT NETWORK POWER GAIN = PG1 BUFFER POWERGAIN = PG2
OUTPUT TERMINATION POWER GAIN = PG3 OUTPUT TRANSFORMER POWER GAIN = PG4
PG=Power Gain (dB)
DEMO BOARD SIGNAL CHAIN:
TRANSFORMATION
GPOITAR
Overall
100 100 24.9 24.9
23.7 0 23.7 0
R1=R3R2=R6
0
PG1
0 3 3
0 0 0 0
PG2
0
PG3
-3 -3 0
0
PG4
0 0 0 0
-3 3 0
1:1 1:1 1:4 1:4TCM4-19+
MABA-007159-000000 MABA-007159-000000
TCM4-19+
T1
-3
0
023.7
200TC8-1G2+
5.15.4200
0
1:8
4.5 0
0
4.51:8
TC8-1G2+
0
JOHN C.2ND PROTOTYPE 21-92-22
__
REVISION HISTORY
ETADNOITPIRCSED APPROVEDECO REV
2
Wednesday, February 29, 2012
1 1
ADC BUFFER
LT
JOHN C.
N/A
LTC6417CUDC
SIZE DATE:
.VER.ONCI
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
V+
V+
V+
V+ V+
J4
C22
680pF
C24
0.1uF
R4
0
C5
0.1uF
C1
0.1uF
E2
R5
0
E4
R1
0
C8
OPT 0603
E5
C9
0.1uF
C14
0.1uF
T1
TCM4-19+
15
34
2
E7
C7
0.1uF
C4
0.1uF
R8
OPT
C13
0.1uF
C11
0.1uF
0603
E3
C10
0.1uF
E1
C18
680pF
J1
R2
100
R3
0
C15
0.1uF
C6
OPT
0603
C12
0.1uF
0603
R7
OPT
C3
0.1uF
C19
0.1uF
C17
0.1uF
C16
680pF
C20
0.1uF
J5
C2
680pF
U1
LTC6417CUDC
6
7
8
9
10 17
18 19
20
11
5
4
3
2
1
12
13
14
15
16
21
V+
GND IN+ IN-
GND GND
OUT-
OUT+
GND
V+
PWRADJ
NC
GND
CL HI
V+
SHUTDOWN
NC
OR
VCM
V+
GND
J3
R6 100
T2
MABA-007159-000000
5 43
1
2
C23
OPT
0603
J2
C21
0.1uF
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DEMO MANUAL DC1660B
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2012
LT 0412 • PRINTED IN USA
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 applica-
tion engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
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