Si7020-A20
Rev. 1.2 7
Table 4. Humidity Sensor
1.9 ≤ V
DD
≤ 3.6 V; T
A
= 30 °C; default conversion time unless otherwise noted.
Parameter Symbol Test Condition Min Typ Max Unit
Operating Range
1
Non-condensing 0 — 100 %RH
Accuracy
2, 3
0 – 80% RH — ±3 ±4 %RH
80 – 100% RH See Figure 2.
Repeatability/Noise 12-bit resolution — 0.025 —
%RH RMS
11-bit resolution — 0.05 —
10-bit resolution — 0.1 —
8-bit resolution — 0.2 —
Response Time
4
τ
63%
1 m/s airflow, with cover — 18 —
S
1 m/s airflow, without cover — 17 —
Drift vs. Temperature — 0.05 — %RH/°C
Hysteresis — ±1 — %RH
Long Term Stability
3
—<0.25 — %RH/yr
Notes:
1. Recommended humidity operating range is 20% to 80% RH (non-condensing) over –10 °C to 60 °C. Prolonged
operation beyond these ranges may result in a shift of sensor reading, with slow recovery time.
2. Excludes hysteresis, long term drift, and certain other factors and is applicable to non-condensing environments only.
See Section “4.1. Relative Humidity Sensor Accuracy” for more details.
3. Drift due to aging effects at typical room conditions of 30 °C and 30% to 50% RH. May be impacted by dust, vaporized
solvents or other contaminants, e.g., out-gassing tapes, adhesives, packaging materials, etc. See Section “4.7. Long
Term Drift/Aging” .
4. Response time to a step change in RH. Time for the RH output to change by 63% of the total RH change.