JAJSOQ6 May 2022 ADC3644
PRODUCTION DATA
The digital output interface uses a flexible output formatter Figure 8-35. The output formatter takes the 14-bit output directly from the ADC or from digital filter block and reformats it to a resolution of 14, 16, 18 or 20-bit. With parallel output format the maximum output resolution supported is 14-bit. With serial CMOS output the output serialization factor gets adjusted accordingly for 2-, 1- and 1/2-wire interface mode. The maximum output data rate can not be exceeded independently of output resolution and serialization factor.
Table 8-7 provides an overview for the resulting serialization factor depending on output resolution and output modes. Note that the DCLKIN frequency needs to be adjusted accordingly as well. Changing the output resolution to 16-bit, 2-wire mode for example would result in DCLKIN = FS * 4 instead of * 3.5.
The output bit formatter can be used for DDC bypass and decimation filter.
OUTPUT RESOLUTION | Interface | SERIALIZATION | FCLK | DCLKIN | DCLK | D0/D1 |
---|---|---|---|---|---|---|
14-bit (default) | 2-Wire | 7x | FS/2 | FS* 3.5 | FS* 3.5 | FS* 7 |
1-Wire | 14x | FS | FS* 7 | FS* 7 | FS* 14 | |
½-Wire | 28x | FS | FS* 14 | FS* 14 | FS* 28 | |
16-bit | 2-Wire | 8x | FS/2 | FS* 4 | FS* 4 | FS* 8 |
1-Wire | 16x | FS | FS* 8 | FS* 8 | FS* 16 | |
½-Wire | 32x | FS | FS* 16 | FS* 16 | FS* 32 | |
18-bit | 2-Wire | 9x | FS/2 | FS* 4.5 | FS* 4.5 | FS* 9 |
1-Wire | 18x | FS | FS* 9 | FS* 9 | FS* 18 | |
½-Wire | 36x | FS | FS* 18 | FS* 18 | FS* 36 | |
20-bit | 2-Wire | 10x | FS/2 | FS* 5 | FS* 5 | FS* 10 |
1-Wire | 20x | FS | FS* 10 | FS* 10 | FS* 20 | |
½-Wire | 40x | FS | FS* 20 | FS* 20 | FS* 40 |
The programming sequence to change the output interface and/or resolution from default settings is shown in Output Interface or Mode Configuration.