Texas Instruments ADS1259EVM, Руководство пользователя

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Digital Interface
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As an indicator, the three settings of S2 are labeled HDR, PGA, and CAL below the switch, as Figure 2
illustrates.
Figure 2. Switch S2 and Jumper J15
When switch S2 is set to the right, jumper J15 is used in the system calibration modes for the ADS1259.
When the jumper is set to the left, pins 1 and 2 of jumper J15 are connected. The inputs of the ADS1259
are shorted together and tied to REFP. With this connection, the user can run an offset calibration. When
the jumper is set to the right, pins 2 and 3 of jumper J15 are connected. The inputs of the ADS1259 are
tied to REFP and REFN, measuring the reference voltage. At this point, the user can run a gain
calibration. On either side of J15, OF and GA indicate the sides of jumper J15 used for offset and gain
calibrations.
Another three-way switch (S3) sets the source of the output common-mode of the PGA280. Setting the
switch to the left connects the output common-mode to pin J8.15 of the analog interface header. The
center setting of the switch connects it to the midpoint between AVDD and AVSS via the voltage divider of
R8 and R9. The right setting connects it to the REFOUT of the ADS1259. These options are labeled under
the switch as HDR, AVDD/2, and REF respectively.
Figure 3 shows S3 as it appears on the
ADS1259EVM.
Figure 3. Switch S3
3 Digital Interface
The ADS1259EVM is designed to easily interface with multiple control platforms. Samtec part numbers
SSW-110-22-F-D–VS-K and TSM-110-01-T-DV-P provide a convenient 10-pin, dual-row, header/socket
combination at J7. This header/socket provides access to the digital control and serial data pins of the
ADC. Consult Samtec at
http://www.samtec.com or call 1-800-SAMTEC-9 for a variety of mating
connector options.
6 ADS1259EVM, ADS1259EVM-PDK SBAU163A – March 2010 – Revised April 2010
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