Hi there,
I decided to measure the internal temperature of AD7175-2 chip on the second channel. The chip is initialized to measure two channels:
- Channel0: Voltage between AIN0+ and AIN0- (Command 0x10 0x8001)
- Channel1: Voltage on internal temperature sensor. (Command 0x11 0x8232)
- Channel3 and 4 are disabled.
- Both channels uses the Setup0 register (Command: 0x20 0x0320)
I use the Single Conversion mode. The data sheet says on page 41:
“…As soon as the conversion is available, the RDY output goes low. The ADC then selects the next channel and begins a conversion…”
But there is no second conversion. The channel0 is converted but even the application waits almost three times more (158µs ) than the first conversion time (41µs) the DOUT/RDY pin stays high and never goes low. What do I do wrong?
Traces:
- Yellow: Chip select of AD7175-2
- Green: Data input of AD7175-2
- Pink: Data output/ Data Ready of AD7175-2
- Blue: Serial clock.
My other notice is. On page 48. Internal Temperature sensor chapter the nominal sensitivity in the text is 470µV/K but in the temperature calculation it is 477µV/K. Which is right? The manual says the temperature in °C = (Conversion Result / 477µV) – 273.15. But the Conversion Result is not the code I read from the converter. First it must be converted to voltage, is not it? Using “Conversion Result” is very confusing.
Thank you for your help!
Best regards,
Louis
Wrong part number in title. I am sorry...
[edited by: Louie88 at 7:44 AM (GMT -5) on 6 Jan 2022]