Datasheet

- 4 -
Table 4: AM2320 pin assignment
Pin
Name
Description
1
VDD
Power supply(3.1-5.5V)
2
SDA
Serial data, bidirectional port
3
GND
Ground
4
SCL
Serial clock input port (single bus ground)
7.2 Power supply pin (VDD GND)
AM2320 supply voltage range of 3.1V - 5.5V.
7.3 Serial clock input (SCL)
The SCL pin is used to communicate the choice and I
2
C sensor communication clock line.
When the power is held low while SCL remains low even 500ms, which means that the user selects a
single bus mode of communication, otherwise I
2
C communications; After selecting the formula
mode during power, sensor communication mode remains unchanged; If you want to change
communication, re-power on, press the select operation requires communication.
When choosing the I
2
C communication between microprocessor and AM2320,SCL for the
synchronous communication.
7.4 Serial data(SDA)
SDA pin is three-state structure for reading, writing sensor data. Detailed Description of
specific communication sequence, see communication method..
8. I
2
C and a single bus
AM2320 serial interface, and power consumption reading sensor signal aspects are optimized
processing. Sensor uses a single bus, I
2
C outputs two communication modes, communication can be
switched freely, easy to use. SCL bus signal line to level when power to determine their bus
communication: SCL is held low on power as a single bus communication mode; SCL remain high
when compared to the power of communication modes I
2
C. Single bus is fully compatible with the
company's other products, single-bus communication; I
2
C communication in accordance with
standard protocols addressing, can be directly linked to the I
2
C bus (the bus is only allowed to
hang a product), without additional wiring, operation simple. Read AM2320 sensors, strictly in
accordance with the agreement of the two communication methods and timing proceed. Specific
details see single communication protocol and I
2
C bus communication protocol detailed.
8.1 I
2
C standard communication protocol introduced
8.1.1 I
2
introduction to C-bus
Another form of AM2320 processor and micro controller interface is I
2
C serial bus, in this
brief introduction about the I
2
C bus protocol standards. Due to space limitations, can’t list all the
contents of the agreement deeper questions, please consult the relevant information (refer to the
Philips website access).