SBASAP6 February 2025 ADC3683-EP , ADC3683-SEP
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
The ADC3683-xEP includes an optional on-chip digital down conversion (DDC) decimation filter that is enabled via SPI register settings. Supporting complex decimation by 2, 4, 8, 16 and 32 using a digital mixer and a 32-bit numerically controlled oscillator (NCO) as shown in Figure 7-21.
Supporting a mode with real decimation where the complex mixer is bypassed (NCO should be set to 0 for lowest power consumption) and the digital filter acts as a low pass filter.
Internally, the decimation filter calculations are performed with a 20-bit resolution to avoid any SNR degradation due to quantization noise limitation. The Section 7.3.5.1 truncates to the selected resolution prior to outputting the data on the digital interface.
Figure 7-21 Internal digital decimation filter