We are evaluating the TMP75C. The datasheet states it has a 12-bit converter. However, the 12-bit value we read always has zero in the least significant two bits. So we are only seeing 10-bit conversion. I don't see anything in the configuration that would cause the device to do a 10-bit conversion. Has anyone seen this device work with 12 bits?
Thanks.
Hi Andrew,
The 12-bit digital output from each temperature measurement conversion is stored in the read-only temperature register. Two bytes must be read to obtain the data, as shown in Figure below:
Note that byte 1 is the most significant byte, followed by byte 2, the least significant byte. The temperature result is left-justified with the 12
most significant bits used to indicate the temperature.
You should be seeing a 12 bit conversion. I got an EVM and a scope to show you the expected results and what you should be seeing.
My EVM reads 26.125°C and on the scope I see the following:
Byte 1: 0001 1010
Byte 2: 0010 0000
Temperature Reading: 0001 1010 0010 = 418 × (0.0625°C / LSB) = +26.125°C
Mayrim Verdejo
MHR Sensing Products | Applications Team
Email: mayrim.verdejo@ti.com
