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SLOU430A – December 2015 – Revised February 2016
Copyright © 2015–2016, Texas Instruments Incorporated
Common Hardware Modifications
Appendix D
SLOU430A – December 2015 – Revised February 2016
Common Hardware Modifications
Low Frequency Support
For low-frequency applications, such as SONAR, that require bandwidth below 200 kHz, the default
assembly of the EVM results in attenuation in this range, and the EVM requires hardware modification.
Simply change all INP and INM capacitors on the LNA inputs to 1 µF (0402). Also, set the internal HPF in
the AFE to the lowest setting. This should support a bandwidth as low 50 kHz, or lower.
External SPI Programming
The AFE EVM allows for external access to the SPI bus for the AFE only, not the LMK device. This is
done by connecting SPI signals at J4 and removing R22 near U9 on the bottom side of the board.
