SNAS817C June 2021 – March 2023 HDC3020-Q1 , HDC3021-Q1 , HDC3022-Q1
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
The Set High Alert, Clear High Alert, Set Low Alert, and Clear Low Alert thresholds are each represented by a truncated 16 bit value, as illustrated Figure 8-26. The 7 MSBs from a relative humidity measurement are concatenated with the 9 MSBs from a temperature measurement. The actual temperature and relative humidity measurement result are always stored as a 16-bit value, but when compared against the programmed threshold values, due to the truncated representation, there is a resolution loss of 0.5°C in temperature and a 1% resolution loss in relative humidity.
The default values of the relative humidity and temperature thresholds after Power Up/Cycle, Hardware Reset, and Soft Reset are documented in Table 8-6 below. Refer to Table 8-3 for the appropriate command to re-program the thresholds.
ALERT THRESHOLD | DEFAULT RH THRESHOLD | DEFAULT T THRESHOLD | HEX VALUE | CRC |
---|---|---|---|---|
Set High Alert | 80% RH | 60°C | 0xCD33 | 0xFD |
Clear High Alert | 79% RH | 58°C | 0xC92D | 0x22 |
Set Low Alert | 20% RH | -10°C | 0x3466 | 0xAD |
Clear Low Alert | 22% RH | -9°C | 0x3869 | 0x37 |