Using Onboard, Second-Order, Butterworth, Low-Pass Filters; Selecting The Reference Mode For The Ads8688Evm - Texas Instruments ADS8688EVM-PDK User Manual

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2.2

Using Onboard, Second-Order, Butterworth, Low-Pass Filters

The ADS8688EVM includes second-order, Butterworth, low-pass filters with a cutoff frequency of 22 kHz
for channels AIN0, AIN1, AIN2, and AIN3. There is also a provision to bypass these filters. See
for an analog input circuit for channels AIN0, AIN1, AIN2, and AIN3.
using onboard, second-order, Butterworth, low-pass filters and
bypassing these filters.
Table 4. Using Onboard, Second-Order, Butterworth, Low-Pass Filters
Channel
AIN0
AIN1
AIN2
AIN3
Table 5. Bypassing the Onboard, Second-Order, Butterworth, Low-Pass Filters
Channel
AIN0
AIN1
AIN2
AIN3
2.3

Selecting the Reference Mode for the ADS8688EVM

The ADS8688EVM can either operate on an internal or external reference.
settings for selecting the reference.
Jumper
J2
Pin
Number
J5.1
J5.2
SBAU230A – August 2014 – Revised December 2014
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Jumper Position
J25 Closed
J31 Closed
J30 Closed
J15 Closed
Jumper Position
J25 Open
J31 Open
J30 Open
J15 Open
Table 7 describes the connections for the external reference.
Table 6. Selecting the Reference for the ADS8688EVM
Position for Using Internal
Reference
Closed
Table 7. External Reference Connections
Signal
REFIN
GND
Copyright © 2014, Texas Instruments Incorporated
Table 4
Table 5 lists the jumper settings for
Jumper Position
J8 Closed between pins 1 and 2
J10 Closed between pins 1 and 2
J11 Closed between pins 2 and 3
J9 Closed between pins 2 and 3
Jumper Position
J8 Closed between pins 2 and 3
J10 Closed between pins 2 and 3
J11 Closed between pins 1 and 2
J9 Closed between pins 1 and 2
Table 6
Position for Using External Reference
Open
Description
Input for external reference
Analog ground connection
ADS8688EVM-PDK Evaluation Module
EVM Analog Interface
Figure 1
lists the jumper settings for
lists the jumper
7