DC1591A - Demo Manual

DEMO MANUAL DC1591A
LTC6409 High Speed, Low
Noise/Distortion Differential
ADC Drivers
DESCRIPTION
Demonstration circuit 1591A features the LTC®6409 differential ADC driver. It incorporates a variety of passive
components to support configurations for varied applications. On this board, two amplifier circuits are provided.
One is single-ended, the other is a differential input and
output. There is also a calibration circuit to de-embed the
effects of other circuit components.
The LTC6409 is a high-speed differential amplifier with
superior distortion and low noise suitable for demanding
communications transceivers, cellular base-stations, and
other high-speed signal chain applications. These fully-
differential amplifiers accept single-ended or differential
inputs with almost no difference in distortion performance.
Each part has the ability to adjust the output common-mode
voltage without any additional components and flexible
input common-mode ranges, which enable input signal DC
coupling and level-shifting for ADC driving applications.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1591A
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
Table 1 shows the function of each SMA connector on the
board. Refer to Figure 1 for the connection diagram and
follow the procedure below:
1.Connect the power supply to V+ and GND as shown in
Figure 1. Typical current consumption of each LTC6409
is about 52mA. Jumper JP1 enables or shuts down
the single-ended amplifier.
2.The power supply voltage range is shown in Figure 1.
Do not exceed the maximum power supply voltage
rating for the parts.
3.Apply an input signal to J1. A low distortion, low noise
signal source with an external high order filter will
yield the best performance. The J1 input is impedance
matched to 50Ω.
4.Observe the output via J2. The output is impedance
matched to 50Ω, suitable for the input of a network or
spectrum analyzer.
Table 1: DC1591A Board I/O Descriptions
CONNECTOR
FUNCTION
J1 (IN)
Single-ended Input. Impedance matched to 50Ω, drive
from a 50Ω network analyzer or signal source.
J2 (OUT)
Single-ended Output. Impedance matched to 50Ω, can
be used to drive a 50Ω network/spectrum analyzer input.
J3 (CAL IN)
Calibration Input. Impedance matched to 50Ω, pairing
with J4 for calibration.
J4 (CAL OUT)
Calibration Output. Impedance matched to 50Ω, pairing
with J3 for calibration to de-embed the effects of other
circuit components.
J5 (IN+)/
J6 (IN–)
Differential Inputs. They are impedance matched to
300Ω differentially. Signal can be driven from preceding
receiver signal chain (i.e., Mixer or I/Q Demodulator).
J7 (OUT–)/
J8 (OUT+)
Differential Outputs. They are impedance matched to
100Ω differentially.
JP1 (SHDN1)
Shutdown Jumper. The lower (EN) position enables the
single-ended amplifier circuit, while the upper (DIS)
puts the amplifier into shutdown mode.
JP2 (SHDN2)
Shutdown Jumper. The lower (EN) position enables the
differential amplifier circuit, while the upper (DIS) puts
the amplifier into shutdown mode.
E4 (VOCM)
Output Common Mode Adjust. By default, this pin is
self-biasing within U1 and U2. Override this voltage
with other DC voltage source as required.
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1
DEMO MANUAL DC1591A
QUICK START PROCEDURE
VCC = 2.7V TO 5.2V
POWER SUPPLY
+
–
IMPEDANCE
MATCHED TO
50Ω
IMPEDANCE
MATCHED TO
50Ω
DC1591A F01
Figure 1. Proper Measurement Equipment Setup
2
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DEMO MANUAL DC1591A
ADDITIONAL INFORMATION
The DC1591A demo board is ready for use out of the
box. A single-ended and a differential amplifier circuit are
provided for ease of use and with minimum modification.
DEMO BOARD VERSIONS
Single-Ended Input and Output Configuration
J1: The single-ended input can be driven from a 50Ω signal
source or network analyzer (usually port 1).
J2: The single-ended output can be connected to spectrum
analyzer or network analyzer (usually port 2).
Differential Inputs and Outputs Configuration
J5 and J6: Differential inputs. Typically, signal input to
these ports are from a receiver signal chain such as a
mixer or I/Q demodulator.
J7 and J8: Differential outputs. These ports can drive
directly into the differential inputs of an ADC.
OUTPUT DRIVE
Each amplifier circuit on the demo board is designed to
have a 50Ω source impedance at its output to facilitate
direct connections to 50Ω terminated test instruments.
ENABLE (SHUTDOWN)
Jumper JP1 and JP2 control the enable function of U1
and U2, respectively, on DC1591A. When set to the EN
position, the part will be on and draws normal operating
current. In the DIS position, the part will be in shutdown
and draws a very small amount of leakage current.
GROUND AND VCC CONNECTIONS
DC1591A’s GND connector is not only connected to V– of
the LTC6409, it also serves as the demo board ground.
For best result, a low impedance return path to the power
supply from GND is recommended. Short, low impedance
wires to the V+ and GND connectors of DC1591A will yield
the best performance from the LTC6409.
DRIVING THE INPUTS DC-COUPLED
It is possible to configure the DC1591A inputs differentially
with DC coupling. Transformer T1 should be removed,
and C23 and C24 connections should be replaced with
0Ω resistors. The inputs are now DC-coupled and can be
driven single-ended or differentially (resistor values may
be changed to balance the source impedances, et cetera.
See the product data sheet for more information. Note
input bias currents will flow through the amplifier’s input
resistors if DC1591A is driven DC-coupled.
SCHEMATIC NOTES
Note that transformer T2 and the series resistors at the
amplifier outputs form a 12.6dB attenuation (if the output
has a 50Ω load) that will affect the measured gain of the
demo board. This is done so that the output of DC1591A can
plug directly into a 50Ω network/spectrum analyzer input,
while the amplifier sees a higher 400Ω load impedance.
CHANGING THE OUTPUT COMMON-MODE VOLTAGE
Turret E4 (VOCM) controls the output common mode
voltage of U1 and U2. E4 can be used to level-shift the DC
output voltage for optimum system performance. If used
for this purpose, transformer T2 should be removed, and
C18 and C19 connections can be replaced by 0Ω resistors
to allow the DC bias to reach the output. By default, the
VOCM voltage is self-biased through resistors internal to
the IC’s (U1 and U2).
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DEMO MANUAL DC1591A
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
1
2
C1, C5
CAP. CHIP, X7R, 100pF, 50V, 10%, 0402
AVX, 04025C101KAT
2
2
C2, C6
CAP. CHIP, X7R, 0.01μF, 16V, 10%, 0402
AVX, 0402YC103KAT
3
19
C3, C7, C11, C14, C15, C16, C18, C19, C20, C21,
C23, C24, C25, C26, C28, C29, C30, C31, C32
CAP. CHIP, X7R, 0.1μF, 16V, 10%, 0402
AVX, 0402YC104KAT
4
2
C4, C8
CAP. CHIP, X5R, 0.47µF, 10V, 10%, 0402
MURATA, GRM155R61A474KE15D
5
2
C9, C10
CAP. CHIP, X7R, 1000pF, 25V, 10%, 0402
AVX, 04023C102KAT
6
1
C12
CAP. CHIP, X5R, 10μF, 10V, 10%, 0805
AVX, 0805ZD106KAT
7
4
C13, C17, C22, C27
CAP. CHIP, X7R, 1.3pF, 25V, 10%, 0402
AVX, 04023J1R3ABWTR
8
3
E1, E3, E4
TESTPOINT, TURRET, 0.065" PBF
MILL-MAX, 2308-2-00-80-00-00-07-0
9
0
E2 (OPT)
TESTPOINT, TURRET, 0.065" PBF
MILL-MAX, 2308-2-00-80-00-00-07-0
10
2
JP1, JP2
HEADER, 3 PINS, 2mm
SAMTEC, TMM-103-02-L-S
11
2
JP1, JP2
SHUNT, 2mm CENTER
SAMTEC, 2SN-BK-G
12
8
J1, J2, J3, J4, J5, J6, J7, J8
CON., SMA 50Ω EDGE-LANCH
CONNEX, 132357 / 142-0701-851
13
8
R1, R7, R14, R18, R27, R31, R36, R37
RES., CHIP, 0Ω 1/16W, 1%, 0402
YAGEO, RC0402FR-070RL
14
0
R2, R6, R13, R15, R16, R19, R26, R32, R35, R38 RES., CHIP, 0402 (OPT)
15
2
R3, R4
RES., CHIP, 100Ω 1/16W, 1%, 0402
YAGEO, RC0402FR-07100RL
16
8
R5, R8, R9, R10, R28, R29, R33, R39
RES., CHIP, 150Ω 1/16W, 0.1%, 0402
YAGEO, RT0402BRE07150RL
17
6
R11, R12, R20, R22, R23, R25,
RES., CHIP, 300Ω 1/16W, 1%, 0402
YAGEO, RC0402FR-07300RL
18
2
R17, R30
RES., CHIP, 10Ω 1/16W, 1%, 0402
YAGEO, RC0402FR-0710RL
19
2
R21, R24
RES., CHIP, 75Ω 1/16W, 1%, 0402
YAGEO, RC0402FR-0775RL
20
2
R34, R40
RES., CHIP, 49.9Ω, 1/16W, 1% 0402
VISHAY, CRCW040249R9FKED
21
4
T1, T2, T3, T4
TRANS., TCM4-19 SURFACE MOUNT
MINI CIRCUITS, TCM4-19
22
2
U1, U2
DIFFERENTIAL AMPLIFIER/ADC DRIVER
LINEAR TECH., LTC6409UDB
23
1
FAB, PRINTED CIRCUIT BOARD
DEMO CIRCUIT # DC1591A
24
2
STENCIL – TOP & BOTTOM
DC1591A
4
dc1591af
A
B
C
D
SMA
J1
1
SMA
CAL IN
J3
5
1
P
Pd
T1
S
CT
Sd
1
2
3
SMA
IN+
R18
0 Ohm
VOCM
J5
R19
OPT
E4
SMA
IN-
J6
1
1
P
Pd
T3
C28
0.1uF
VCM
S
CT
1
2
3
R31
0 Ohm
EN
DIS
R38
OPT
R32
OPT
JP2
SHDN2
3
2
1
JP1
3
2
1
C30
R30
10
150 0.1%
R39
150 0.1%
R33
C26
0.1uF
4
C31
-IN
Vocm
+IN
R23
300
R20
300
6
5
2
C16
0.1uF
6
5
2
C27
1.3pF
1.3pF V+
C13
150 0.1%
R28
R25
300
R22
300
R24
75
-IN
Vocm
+IN
V+
+OUT
-OUT
C14
0.1uF
C15
0.1uF
-OUT
R8
150 0.1%
R21
75
U2
LTC6409UDB
0.1uF
C20
0.1uF
VOCM
VOCM
150 0.1%
R10
R9
150 0.1%
R11
300
R17
10
0.1uF
C32
0.1uF
SHDN1
Sd
EN
DIS
E2
VCM
C24
C23
0.1uF
0.1uF
R12
300
TCM4-19
1:4 Xfmr by Mini-Circuits
4
6
R15
OPT
C25
0.1uF
R37
0 Ohm
R16
OPT
V+
TCM4-19
1:4 Xfmr by Mini-Circuits
4
6
CALIBRATION PATH
R13
OPT
R14
0 Ohm
U1
LTC6409UDB
C22
1.3pF
+OUT
R29
150 0.1%
C17
1.3pF
SHDN
3
IN
5
4
3
2
R5
150 0.1%
SHDN
3
E
5
4
3
2
4
9
V+
V+
VVV8
10
11
4
7
1
7
1
50
R40
50
R34
0.1uF
C21
R4
100
R3
100
C18
Sd
CT
S
T4
Pd
P
6
4
C29
0.1uF
R6
OPT
R35
OPT
3
R7
0 Ohm
R36
0 Ohm
TCM4-19
1:4 Xfmr by Mini-Circuits
3
2
1
0.1uF
C19
0.1uF
3
1
Sd
CT
S
1
T2
P
Pd
6
4
J7
J8
SMA
OUT+
SMA
OUT-
R26
OPT
R27
0 Ohm
TCM4-19
1:4 Xfmr by Mini-Circuits
3
2
1
2
3
4
5
4
9
V+
V+
VVV8
10
11
5
4
3
2
5
4
3
2
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
2
3
4
5
R1
1
0 Ohm
1
J4
SMA
J2
OUT
2
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
CUSTOMER NOTICE
SMA
CAL OUT
2
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.
R2
OPT
2
3
4
5
2
3
4
5
5
SCALE = NONE
APP ENG. JOHN C.
PCB DES. NC
APPROVALS
2
-
E3
DATE:
N/A
SIZE
TECHNOLOGY
0.47uF
1
LTC6409UDB
DEMO CIRCUIT 1591A
Thursday, June 10, 2010
IC NO.
DATE
06-02-10
SHEET 1
OF
1
2
REV.
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
C8
0.1uF
0.01uF
C7
100pF
0.1uF
0.47uF
C4
C6
0.01uF
C3
C5
100pF
C2
JOHN C.
APPROVED
C1
PRODUCTION FAB
DIFFERENTIAL AMPLIFIER / ADC DRIVER
TITLE: SCHEMATIC
GND
V+
1
DESCRIPTION
REVISION HISTORY
C9
C12 C11 C10
10uF 0.1uF 1000pF 1000pF
E1
V+
2.7V - 5.25V
REV
ECO
A
B
C
D
E
DEMO MANUAL DC1591A
SCHEMATIC DIAGRAM
dc1591af
5
DEMO MANUAL DC1591A
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 application
engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
6
dc1591af
Linear Technology Corporation
LT 1115 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2015
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