SI7050-A20 Datasheet, PDF (15/26 Pages) Silicon Laboratories – IC TEMPERATURE SENSORS

Si7050/3/4/5-A20
5.3. Electronic Serial Number
The Si705x provides a serial number individualized for each device that can be read via the I²C serial interface.
Two I²C commands are required to access the device memory and retrieve the complete serial number. The
command sequence, and format of the serial number response is described in the figure below:
First access:
S
S
2nd access:
S
S
Slave Address W
Slave Address R
SNA_3
ACK
SNA_1
ACK
Slave Address W
Slave Address R
SNB_3
ACK
SNB_1
ACK
Master
Slave
ACK 0xFA ACK 0X0F
ACK
CRC
ACK SNA_2 ACK
CRC
ACK SNA_0 ACK
ACK
0xFC
ACK
0XC9
ACK
SNB_2 ACK
CRC
ACK
SNB_0 ACK
CRC NACK
ACK
CRC ACK
CRC NACK P
ACK
P
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 devices. The
value of this field maps to the following devices according to this table:
0x00 or 0xFF engineering samples
50 = 0x32 = Si7050
53 = 0x35 = Si7053
54 = 0x36 = Si7054
55 = 0x37 = Si7055
Rev. 1.0
15