Texas Instruments ADS848 EVM Series User Manual page 9

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6 Using the ADS848xEVM
The ADS848xEVM functions as a reference design, a prototyping board, and a software test platform.
6.1 As a Reference Design
As a reference design, the ADS848xEVM contains the essential circuitry to showcase the analog-to-digital
converter. This essential circuitry includes the input amplifier, reference circuit, and buffers. The
ADS848xEVM analog input circuit is optimized for a wide bandwidth signal; therefore, the user may need
to adjust the input buffer circuitry to better suit specific needs. In ac-type applications where signal
distortion is a concern, the user should use high-quality capacitors such as mica, polypropylene, or
COG-type capacitors in the signal path. In applications where the input is multiplexed, the A/D input
resistor and capacitor may need to be adjusted further.
6.2 As a Prototype Board
As a prototype board, the ADS848xEVM features amplifiers in a standard 8-pin SOIC package. The board
contains many resistor pads that allow the user to experiment with a host of circuits as desired. The
ADS848xEVM can be used to evaluate both dual- and single-supply amplifiers in both inverting and
noninverting configurations. The ADS848xEVM comes installed with a dual-supply amplifier that allows the
user to take advantage of the full input voltage range of the converter. For applications that require
single-supply operation and a smaller input voltage range, the THS4031 can be replaced with the
single-supply amplifier such as the
pads 1 and 2. This configuration shorts the minus supply pin of the amplifier to ground. Positive supply
voltage can be applied at test point TP4 or at connector J5 pin 1.
6.3 As a Software Test Platform
As a software test platform, connectors P1, P2, and P3 plug into the parallel interface connectors of the
5-6K Interface Board. The 5-6K Interface Board sits on the C5000™ and C6000™ digital signal processor
starter kits (DSK). The ADS848xEVM is then mapped into the processor memory space. The 5-6k
Interface Board also provides an area for signal conditioning. This area can be used to install application
circuit(s) for digitization by the ADS848x analog-to-digital converter. For more information, see the 5-6K
Interface Board User's Guide (SLAU104) .
For the software engineer, the ADS848xEVM provides a simple platform for interfacing to the converter.
The EVM provides standard 0.1-inch headers and sockets to wire into prototype boards. The user must
provide only three address lines (A2, A1, and A0) and address valid line (DC_CS) to connector P2. To
select which address combinations generate RD and CONVST, set the jumpers as shown in
Recall that the Chip Select (CS) signal is not memory-mapped or tied to P2; therefore, it must be
controlled by a general-purpose pin or shorted to ground at J3 pin 1. If address decoding is not required,
the EVM provides direct access to converter data bus by P3 and control by J3.
SLAU186A – August 2006 – Revised September 2008
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OPA300 or OPA350. Pad jumper SJP3 should be shorted between
Using the ADS848xEVM
Table 4.
ADS848xEVM 9