SBAS976A May 2019 – May 2020 ADS7138
PRODUCTION DATA.
The device uses an internal oscillator for conversions. When using the averaging module, the host initiates the first conversion and all subsequent conversions are generated internally 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.