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AMC1336-Q1

SBASA51 – MAY 2020

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Copyright © 2020, Texas Instruments Incorporated

8 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component

specification, and TI does not warrant its accuracy or completeness. TI’s customers are

responsible for determining suitability of components for their purposes. Customers should

validate and test their design implementation to confirm system functionality.

8.1 Application Information

8.1.1 Digital Filter Usage

The modulator generates a bitstream that is processed by a digital filter to obtain a digital word similar to a

conversion result of a conventional analog-to-digital converter (ADC). Equation 2 shows a sinc3-type filter, which

is a very simple filter that is built with minimal effort and hardware:

(2)

This filter provides the best output performance at the lowest hardware size (count of digital gates) for a second-

order modulator. All the characterization in this document is also done with a sinc3 filter with an oversampling

ratio (OSR) of 256 and an output word width of 16 bits.

An example code for implementing a sinc3 filter in an FPGA is discussed in the Combining the ADS1202 with an

FPGA Digital Filter for Current Measurement in Motor Control Applications application note, available for

download at www.ti.com.