SBAS868A May 2019 – May 2020 ADS7128
PRODUCTION DATA.
The device uses an internal oscillator for conversions. When using the averaging module or the RMS module, the host initiates the first conversion and all subsequent conversions are generated internally by the device. However, in the autonomous mode of operation, the start of the conversion signal is generated by the device. Table 8 shows that when the device generates the start of the conversion, the sampling rate is controlled by the OSC_SEL and CLK_DIV[3:0] register fields.
CLK_DIV[3:0] | OSC_SEL = 0 | OSC_SEL = 1 | ||
---|---|---|---|---|
SAMPLING FREQUENCY, fCYCLE (kSPS) | CYCLE TIME, tCYCLE (µs) | SAMPLING FREQUENCY, fCYCLE (kSPS) | CYCLE TIME, tCYCLE (µs) | |
0000b | 1000 | 1 | 31.25 | 32 |
0001b | 666.7 | 1.5 | 20.83 | 48 |
0010b | 500 | 2 | 15.63 | 64 |
0011b | 333.3 | 3 | 10.42 | 96 |
0100b | 250 | 4 | 7.81 | 128 |
0101b | 166.7 | 6 | 5.21 | 192 |
0110b | 125 | 8 | 3.91 | 256 |
0111b | 83 | 12 | 2.60 | 384 |
1000b | 62.5 | 16 | 1.95 | 512 |
1001b | 41.7 | 24 | 1.3 | 768 |
1010b | 31.3 | 32 | 0.98 | 1024 |
1011b | 20.8 | 48 | 0.65 | 1536 |
1100b | 15.6 | 64 | 0.49 | 2048 |
1101b | 10.4 | 96 | 0.33 | 3072 |
1110b | 7.8 | 128 | 0.24 | 4096 |
1111b | 5.2 | 192 | 0.16 | 6144 |
The conversion time of the device (see tCONV in the Switching Characteristics table) is independent of the OSC_SEL and CLK_DIV[3:0] configuration.