QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1384
16-BIT, DIFFERENTIAL, DELTA SIGMA ADC WITH SPI INTERFACE
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LTC2452
DESCRIPTION
Demonstration circuit 1384 features the LTC2452, a
16 bit high performance differential ∆Σ analog-to-
digital converter (ADC) with an SPI interface. The in-
put is bipolar with a range of Ref-to Ref+. The modu-
lator’s proprietary sampling technique reduces the
average input current to less than 50nA – orders of
magnitude lower than typical delta sigma ADCs. The
LTC2452 is available in an 8 pin, 3x2mm DFN pack-
age and has an easy to use SPI interface.
DC1384 is a member of Linear Technology‘s
QuickEval™ family of demonstration boards. It is de-
signed to allow easy evaluation of the LTC2452 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 evaluat-
ing with Linear Technology’s software, the digital sig-
nals can be connected to the end application’s proc-
essor / controller for development of the serial inter-
face.
Design files for this circuit board are available. Call
the LTC factory.
LTC is a trademark of Linear Technology Corporation
Figure 1. Proper Measurement Equipment Setup
QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1384
16-BIT, DIFFERENTIAL, DELTA SIGMA ADC WITH SPI INTERFACE
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QUICK START PROCEDURE
Connect 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 refer-
ence 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
QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1384
16-BIT, DIFFERENTIAL, DELTA SIGMA ADC WITH SPI INTERFACE
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HARDWARE SET-UP
CONNECTION TO DC590 SERIAL CONTROLLER
J1 is the power and digital interface connector.
Connect to DC590 serial controller with supplied 14
conductor ribbon cable.
JUMPERS
JP1 – Select the source for REF+, either an LT6660-
5 or from an external source connected to the Ref+
turret post.
ANALOG CONNECTIONS
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 ex-
posed ground planes along the edges of the board
may be used to form a solid connection between
grounds.
GND – This turret is connected directly to the inter-
nal ground planes.
VCC – This is the supply voltage for the ADC.
REF+ –This is the reference voltage for the ADC.
May be used to drive the reference pin if JP1 is set
to Ext.
IN+ – This is the positive input to the ADC.
IN - – This is the negative input to the ADC.
QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1384
16-BIT, DIFFERENTIAL, DELTA SIGMA ADC WITH SPI INTERFACE
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