SI7021-A20 Datasheet, PDF (24/36 Pages) Silicon Laboratories – IC HUMIDITY AND TEMPERATURE SENSOR

Si7021-A20
The format of the complete serial number is 64-bits in length, divided into 8 data bytes. The complete serial number
sequence is shown below:
SNA_3
SNA_2
SNA_1
SNA_0
SNB_3
SNB_2
SNB_1
SNB_0
The SNB3 field contains the device identification to distinguish between the different Silicon Labs relative humidity
and temperature devices. The value of this field maps to the following devices according to this table:
0x00 or 0xFF engineering samples
0x0D=13=Si7013
0x14=20=Si7020
0x15=21=Si7021
5.4. Firmware Revision
The internal firmware revision can be read with the following I²C transaction:
Slave
S
W
A
0x84
A
Address
0xB8
Slave
A
S
Address
RA
FWREV
The values in this field are encoded as follows:
0xFF = Firmware version 1.0
0x20 = Firmware version 2.0
A NA P
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Rev. 1.1