DEMO MANUAL DC1629A
LTC2472: Selectable
250sps/1ksps 16-Bit, Differential,
∆Σ ADC with SPI Interface
DESCRIPTION
Demonstration circuit 1629A features the LTC2472, a
16-bit high performance Δ∑ analog-to-digital converter
(ADC) with an SPI interface. The input is differential with
a range of ±VREF The modulator’s proprietary sampling
technique reduces the average input current to less than
50nA – orders of magnitude lower than typical delta
sigma ADCs.
DC1629A is a member of Linear Technology‘s QuikEval™
family of demonstration boards. It is designed to allow easy
evaluation of the LTC2472 and may be connected directly
to the target application’s analog signals while using the
DC590 USB Serial Controller board and supplied software
to measure performance. The exposed ground planes allow
proper grounding to prototype circuitry. After evaluating
with Linear Technology’s software, the digital signals can
be connected to the end application’s processor/controller
for development of the serial interface.
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 and
QuickEval is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
RIBBON CABLE
TO DC590 CONTROLLER
INPUTS
Figure 1. Proper Measurement Equipment Setup
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DEMO MANUAL DC1629A
QUICK START PROCEDURE
Connect DC1629A to a DC590 USB Serial Controller using
the supplied 14-conductor ribbon cable. Connect DC590
to host PC with a standard USB A/B cable. Run the evaluation software supplied with DC590 or downloaded from
http://www.linear.com/software. The correct program will
be loaded automatically. Click the COLLECT button to start
reading the input voltage. Details on software features are
documented in the control panel’s help menu.
Tools are available for logging data, changing reference
voltage, changing the number of points in the strip chart
and histogram, and changing the number of points averaged for the DVM display.
Figure 2. Software Screenshot
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DEMO MANUAL DC1629A
HARDWARE SET-UP
CONNECTION TO DC590 SERIAL CONTROLLER
GND: This turret is connected directly to the internal
ground planes.
J1 is the power and digital interface connector. Connect
to DC590 serial controller with supplied 14-conductor
ribbon cable.
VCC: This is the supply and reference voltage for the ADC.
Do not draw any power from this point.
ANALOG CONNECTIONS
IN+: This is the positive input to the ADC. The maximum
differential voltage between IN+ and IN– is ±1.25V.
Analog signal connections are made via the row of turret
posts along the edge of the board. Also, when connecting
the board to an existing circuit the exposed ground planes
along the edges of the board may be used to form a solid
connection between grounds.
IN–: This is the negative input to the ADC
REFOUT: This turret is connected to the LTC2472 REFOUT
pin. This pin may be used to provide a reference voltage
to an external circuit and can source up to 100μA. Do NOT
drive this pin. This pin is normally at 1.25V.
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DEMO MANUAL DC1629A
PARTS LIST
ITEM
QUANTITY
1
7
2
1
REFERENCEDESCRIPTION
PART DESCRIPTION
MANUFACTURER, PART NUMBER
REQUIRED CIRCUIT COMPONENTS
C1, C2, C3, C4, C5,
C7, C8
Capacitor, 0402, 0.1μF, 20%, 16V, X7R
TDK C1005X7R1C104M
C6
Capacitor, 0603, 10μF, 20%, 6.3V, X5R
TDK C1608X5R0J106M
C6 - Alternate
Capacitor, 0603, 10μF, 20%, 6.3V, X5R
Murata GRM188R60J106ME47D
3
5
E1, E2, E3, E4, E5
4
1
J1
Turret
Mill Max 2308-2
Header, 2mm × 7mm 2mm
Molex 878311420
5
2
R1, R5
Resistor, 0402, 1kΩ, 5%, 1/16W
Vishay CRCW0402102JNED
6
3
R2, R3, R4
7
1
U1
Resistor, 0402, 4.99kΩ, 1%, 1/16W
IC, 16-Bit ADC w/Integrated Precision Refrence Linear Technology LTC2472CDD
Vishay CRCW04024K99FKED
8
1
U2
IC, IC Serial EEPROM 2k
Microchip Technology 24LC025-I/ST
9
1
Fab, Printed Circuit Board
Demo Circuit 1629A
10
1
Stencil
Stencil 1629A
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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.
A
B
C
GND
VCC
IN-
IN+
REFOUT
E4
E3
E5
E1
E2
5
VCC
1K
R5
1K
R1
C3
0.1uF
0.1uF
0.1uF
C8
C7
C2
0.1uF
U1
LTC2472CDD
1%
1%
$33529$/6
R3
4.99K
4
3
7+,6&,5&8,7,635235,(7$5<72/,1($57(&+12/2*<$1'
6833/,(')2586(:,7+/,1($57(&+12/2*<3$576
1
REV
6&$/( 121(
A0
A1
A2
WP
SCL
5
1%
R4
4.99K
PRODUCTION
TECHNOLOGY
14
12
9
10
11
5
7
4
6
2
1
NC
EEGND
EESDA
EEVCC
EESCL
MISO
MOSI/SDA
SCK/SCL
CS
5V
VUNREG
J1
06/01/10
DATE
1
LEO C.
APPROVED
,&12
LTC2472CDD
2
1
6+((7 1
DEMO CIRCUIT 1629A
'$7( Tuesday, June 01, 2010
N/A
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16-BIT DIFFERENTIAL DELTA SIGMA SPI ADC
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C5
VCC
DESCRIPTION
REVISION HISTORY
U2
24LC025-I/ST
SDA
2
7,7/( 6&+(0$7,&
1
2
3
7
6
&6 6&. 6', 6'
TP7
R2
4.99K
10uF
0.1uF
3
CS
SCK 5
4
SDI
6
SDO
C6
C4
&86720(5127,&(
IN-
IN+
VCC
/,1($57(&+12/2*<+$60$'($%(67())25772'(6,*1$
&,5&8,77+$70((76&86720(56833/,('63(&,),&$7,216
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$33(1* /(2&
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&,5&8,7%2$5'/$<2870$<6,*1,),&$17/<$))(&7&,5&8,7
3(5)250$1&(255(/,$%,/,7<&217$&7/,1($5
7(&+12/2*<$33/,&$7,216(1*,1((5,1*)25$66,67$1&(
10
9
0.1uF
12
C1
1
REFOUT
2
COMP
GND
GND
GND
13
11
7
VCC
REF8
ECO
8
3
GND
3
D
4
GND
8
VCC
GND
4
GND
13
5
A
B
C
D
DEMO MANUAL DC1629A
SCHEMATIC DIAGRAM
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DEMO MANUAL DC1629A
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
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Linear Technology Corporation
LT 0411 REV A • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2010