Datasheet

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This section describes the I
2
C interface characteristics AM2320 sensor, if you want to get the
best communication with the sensor results, designed in strict compliance with the conditions of
Figure 13 and Table 6 design.
Figure 1 13 3: AM2320 typical application circuit I2C bus and timing diagram
Table 6 : AM2320 sensor C interface characteristics
Symbol
Parameters
Standard C mode
Unit
min
Max
SCL clock frequency
100
kHz
T w (SCLL)
SCL Clock low time
4.7
μs
T w (SCLH)
SCL Clock high time
4.0
T s u (SDA)
SDA Settling time
250
ns
T h (SDA)
SDA Data hold time
T r (SDA)
T r (SCL)
SDA and SCL Rise time
1000
T f (SDA)
T f (SCL)
SDA and SCL Fall Time
300
T h (STA)
Start condition hold time
4.0
μs
T s u (STA)
Repeated Start condition setup time
4.7
T s u (STO)
Stop condition setup time
4.0
μs
T w (STO:STA)
Stop to Start condition time (bus idle)
4.7
μ
s
C b
Capacitive load for each bus
400
P F
8.2.3 Communication protocol
I
2
C protocol AM2320 sensor is based on the standard I
2
C bus protocol, the reference to the
Mod Bus protocol, according to AM2320 sensor itself features a combination of I
2
C Mod Bus
agreement. Specific format is as follows:
◎Communication data (information frame) format
Data formats:
Data length:
◎
Communication and information transfer process
I
2
C data+W/R
Function Code
Data Area
CRC
1byte
1 byte
N-byte
16-bit CRC (cyclic redundancy code)