ATH25 Data Sheet

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Version:V1.0 —— May 2021

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7.

75%RH can be easily generated from saturated NaCl.

5 Interface Definition

Pins

Name

Describe

1

VDD

Power supply(2.2v to 5.5v)

2

SDA

Serial Data Bidirectional

port

3

GND

Ground

4

SCL

Serial clock Bidirectional

port

Table 5. ATH25 pin distribution (top view)

5.1 Power Pin(VDD,GND)

The power supply range of ATH25 is 2.2-5.5V.

5.2 Serial Clock SCL

The serial clock is used to synchronize the communication between the microprocessor and

ATH25. Since the interface contains completely static logic, there is no minimum SCL

frequency.

5.3 Serial Data SDA

The SDA pin is used for data input and output of the sensor. When sending a command to the

sensor, SDA is valid on the rising edge of the serial clock (SCL), and when SCL is high, SDA

must remain stable. After the falling edge of SCL, the SDA value can be changed. To ensure

communication safety, the effective time of SDA should be extended by TSU and THO before the

rising edge and after the falling edge of SCL refer to Figure 9. When reading data from the

sensor, SDA is valid (TV) after SCL goes low, and is maintained until the next falling edge of

SCL.

Figure 8. Typical application circuit

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