Part Number: ADS1258 Tool/software: I need to sample a single analog input at 30kHz or 60kHz (or an exact rate close to that), and that needs to be an exact sample rate controlled by the START signal. For discussion that's about 33us or 17us between conversions. So, I'm using fixed channel conversion, and I have the START signal controlled by an external timer in the MCU. For the 30kHz, I'll set DRATE to 31250 SPS, and for 60kHz, it'll need to be 125000 SPS. At 31250SPS, the conversion should be finished in 32us, and I want to start the next conversion at about 33us, only 1us later. If I'm reading the datasheet correctly, and if the converter goes into standby too quickly, I may have a 50us delay (table 11)? Is there a time window before the converter drops in to standby, or can I keep the converter active for that 1-2us so that it starts on time. It seems a little absurd to insert a 50us delay into a 33us conversion process. I cant imaging that it jumps from 32us to 82us. I would think the part is capable of sampling at 30kHz. How would I configure the part to do this. Would a longer/higher duty cycle START pulse help delay this issue. (e.g. 25us every 33us). In short, I want to sample at exactly 30kHz and 60kHz determined by the MCU. Is that possible?
↧