LINEAR TECHNOLOGY DC1011A Evaluation Board Instruction Manual
- June 3, 2024
- LINEAR TECHNOLOGY
Table of Contents
DEMO MANUAL DC1011A
LTC2498, LTC2496, LTC2494
24-bit/16-bit, 8-/16-Channel, Easy Drive
ΔS ADC with SPI Interface
Description
Demonstration Circuit 1011A-A features the LT C ® 2498 8-/16-channel, 24-bit
Delta Sigma ADC with Easy Drive™ inputs. Key DC specifications include 2ppm
INL, 1ppm offset, 25ppm full-scale error and 10nV/°C offset drift. In the
6.9Hz/280nVRMS mode, input normal mode rejection of 50Hz and 60Hz noise is
better than 87dB. DC1011A-B features the LTC2496 16-bit Δ∑ ADC that is pinout
and software compatible with the LTC2498. DC1011A-C features the LTC2494
16-bit Δ∑ ADC with internal PGA and temperature sensor. DC1011A is a member of
Linear Technology’s QuikEval™ family of demonstration boards. It is designed
to allow easy evaluation of the LTC2498, LTC2496 or LTC2494 and may be
connected directly to the target application’s analog signals while using the
DC590 USB Serial Control- ler board and QuikEval software to measure
performance. The exposed ground planes allow proper grounding to prototype
circuitry. After evaluating with LT C ’s software, the digital signals can be
connected to the application’s processor/controller for development of the
serial interface.
Design files for this circuit board are available at
http://www.linear.com/demo
, LT, LTC, LTM, Linear Technology and the Linear logo are registered
trademarks and Easy Drive and QuikEval are trademarks of Linear Technology
Corporation. All other trademarks are the property of their respective
owners. 
Quick start proceDure
Connect the DC1011A 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
www.linear.com/software. The correct program
will be loaded automatically. Click the COLLECT button to start reading the
input voltage. Click the slider at the bottom of the strip-chart display to
change the oversample ratio (OSR) which will in turn change the data output
rate. 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.
HarDware setup
JuMPErS
JP1, JP3: Select the source for REF+ and REF–, respectively. REF+ can be 5V
from the on-board LT1236 reference (default) or supplied externally. REF– can
be Ground (0V, default) or supplied externally. JP2: Select source for analog
COM input, either tied to ground or supplied externally to the COM turret
post.
ConnECtion to DC590 SErial ControllEr
J2 is the power and digital interface connector. Connect to a DC590 serial
controller with the supplied 14-conductor ribbon cable. Digital signals are
also connected to through hole test points on the circuit board.
Analog ConneCtions
Analog signal connections are made via the row of turret posts along the
edge of the board. Also, if you are 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.
gnD: Ground turrets are connected directly to the internal analog ground
plane.
PWr gnD: Power ground, connected to the power return trace.
VCC: This is the supply for the ADC. Do not draw any power from this point.
External power may be applied to this point after disabling the VCC supply on
DC590. See the DC590 quick start guide for details.
REF+,REF–: These turrets are connected to the LTC2496/2498/2494 REF+ and REF–
pins. If the onboard reference is being used, the reference voltage may be
monitored from this point. An external reference may be connected to these
terminals if JP1 and JP3 are configured for external reference.
Note: The REF+ and REF– terminals are decoupled to ground with 0.1μF and 10μF
capacitors in parallel. Thus any source connected to these terminals must be
able to drive a capacitive load and have very low impedance at DC. Examples
are series references that require an output capacitor and C-load stable op
amps such as the LT1219 and LT1368. CH0 to CH15: These are the differential
inputs to the LTC2496/2498/2494. They may be configured either as single-ended
inputs with respect to the COM pin, or adjacent pairs may be configured as
differential inputs (CH0-1, CH2-3, etc.)
experiments
INPUT NOISE Solder a short wire between the CH0 and CH1 turrets. Connect the inputs to ground through a short wire and start taking data. LTC2498 Noise should be approximately 0.12ppm of 5V (600nVRMS). The electrical noise of the LTC2496 is also 600nVRMS, however this is masked by the 76.3µV quantization level. If the input is midway between code transitions, the noise level will read zero. If the input is exactly on a code transition such that the two adjacent output codes have equal probability, the noise level will be approximately 7.9ppm.
COMMON MODE REJECTION
Tie the two inputs (still connected together from previous experiment) to
ground through a short wire and note the indicated voltage. Tie the inputs to
REF+; the difference should be less than 5μV due to the 120dB+ CMRR of the
LTC2498. The LTC2496 will produce less than 1LSB difference.
INPUT NORMAL MODE REJECTION
The LTC2498’s SINC4 digital filter can be software selected to reject 50Hz,
60Hz by 120dB, or both 50Hz and 60Hz by 87dB. The LTC2496’s SINC4 filter is
fixed at 50/60Hz. To measure input normal mode rejection, connect COM to a
2.5V source such as an LT1790-2.5 reference or a power supply. Connect any
other input (CH0 to CH15) to the same supply through a 10k resistor. Apply a
10Hz, 2V peak-to-peak sine wave to the input through a 1µF capacitor. Set the
rejection frequency to 55Hz (LTC2498 only) and start taking data. The input
noise will be quite large, and the graph of output vs time should show large
variations. Next, slowly increase the frequency to 55Hz. The noise should be
almost undetectable in the graph. Note that the indicated noise in ppm may
still be above that of the data sheet specification because the inputs are not
connected to a DC accurate source.
Parts List
ITEM| QTY| REFERENCE| PART DESCRIPTION|
MANUFACTURER/PART NUMBER
---|---|---|---|---
lequired Circuit Components
1| 4| C3, C7, C10, C13| CAP., CHIP X7R 0.01pF 16V| AVX, 0603YC103KAT1A 0603
2| 2| C11, C15| CAP., CHIP X7R 0.1pF 16V 10%| AVX, 0603YC104MAT1A 0603
3| 1| C29| CAP., CHIP X5R 1 pF 101/| TAIYO YUDEN, LMK107BJ105KA 0603
4| 3| C2, C9, C12| CAP., CHIP X5R 4.7pF 6.3V| TAIYO YUDEN, JMK212BJ475MG 0805
5| 1| C8| CAP., CHIP X5R 10pF 6.3V| TDK, C2012X5R0J106M 0805
6| 25| TP1-TP6, TP8, TP1O-TP12, TP14-TP27, TP31| TURRET, TESTPOINT 0.064″|
MILL-MAX, 2308-2
7| 0| TP7, TP9, TP13, TP28-TP30, TP32-TP35| OPT. (SURFACE MOUNT PAD ONLY)|
8| 3| JP1-JP3| HEADER, 3-PIN 1 ROW 0.079CC| SAMTEC, TMM-103-01-LD
9| 3| FOR ( JP1-JP3)| SHUNT, 0.079″ CENTER| SAMTEC, 2SN-BK-G
10| 1| J2| HEADER, VERTICAL DUAL 2X7 0.079CC| MOLEX, 87831-1420
11| 2| R1, R2| RES., CHIP OQ| VISHAY, CRCW06030000Z0EA
12| 1| R6| RES., CHIP 10012 5%| MC, CR16-101JM 0603
13| 3| R8, R9, R10| RES., CHIP 4.99k 1%| MC, CR16-4991FM 0603
14| 1| R12| RES., CHIP 10k 5%| MC, CR16-103JM 0603
15| 1| U4| I.C., PRECISION REFERENCE S08| LINEAR TECH., LT1236ACS8-5#PBF
16| 1| U3| I.C., SERIAL EEPROM, TSSOP-8| MICROCHIP, 24LCO25-I/ST (PbF)
3C1011A-A
1| 1| 1 U1| I.C., 24-BIT 8416-CHANNEL DELTA SIGMA ADCs| LINEAR TECH.,
LTC2498CUHF 380FN
3C1011A-B
1| 1| 1 U1| I.C., 16-BIT 8-/16-CHANNEL DELTA SIGMA ADCs| LINEAR TECH.,
LTC2496CUHF 380FN
3C1011A-C
1| 1| U1| I.C., 16/PGA 8-116-CHANNEL DELTA SIGMA ADCs| LINEAR TECH.,
LTC2494CUHF 38QFN
Schematic Diagram
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.
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
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If this evaluation kit does not meet the specifications recited in the DEMO
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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.
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Copyright © 2004, Linear Technology Corporation
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References
- Product Evaluation Boards and Kits | Design Center | Analog Devices
- Design Tools & Calculators | Design Center | Analog Devices