3 Interface definition

Pin

name

Interpretation

6

2

5

3

4

1

ADR

Power ground

2

SDA

Serial data

3

SCL

Serial clock

4

VDD

Supply voltage

5

GND

Power ground

6

NC

Stay vacant

Table 5 AHT10 pin distribution (top view).

3.1 Power supply pin (VDD, GND)

AHT10 power supply range of 1.8-3.6V,

recommended voltage is 3.3V. A 100nF decoupling

capacitor must be connected between the power

supply ( VDD ) and ground ( GND ) and the

capacitor should be placed as close as possible to

the sensor - see Figure 11 .

3 . 2 Serial clock SCL

SCL is used for communication synchronization

between the microprocessor and the AHT10 . Since

the interface contains completely static logic, there

is no minimum SCL frequency.

3.3 serial data SDA

The SDA pin is used for data input and output of

the sensor. SDA is active on the rising edge of the

serial clock ( SCL ) when a command is sent to the

sensor , and SDA must remain stable when SCL is

high . After the falling edge of SCL , the SDA value

can be changed. To ensure communication

security, the effective time of the SDA should be

extended to TSU and THO before and after the

rising edge of SCL - see Figure 12 . When reading

data from the sensor, SDA is low after SCL active

(TV), and maintained until the falling edge of SCL.

Figure 11 shows a typical application circuit that includes a pull-up resistor RP

and a decoupling capacitor between VDD and GND。

Note : 1. The power supply voltage of the host MCU must be consistent with

the sensor when the product is in use .

2, To further improve the reliability of the system, the sensor power can be

controlled.

3, Only a single AHT10 can be connected to the I 2 C bus and no other I 2 C

devices can be connected .

To avoid signal collisions, the microprocessor ( MCU )

must only drive SDA and SCL low. An external pull-up

resistor (eg 10k Ω ) is required to pull the signal high.

Pull-up resistors are usually already included in the

microprocessor In the I/O circuit. Reference table 7

and table 8 can get detailed information about sensor

input / output characteristics.

4 Electrical characteristics

4.1 Absolute maximum rating

The electrical characteristics of AHT10 are defined in

Table 1 . The absolute maximum ratings given in

Table 6 are stress ratings only and provide more

information. Under such conditions, it is not

advisable for the device to perform functional

operations. Prolonged exposure to absolute

maximum ratings may affect sensor reliability.

parameter

Minimum

maximum

unit

VDD to GND

-0.3

3.6

V

Digital I/O pin(SDA,

SCL)

toGND

-0.3

VDD +0.3

V

Input current per pin

-10

10

mA

Table 6 Electrical Absolute Maximum Ratings

ESD electrostatic discharge meets JEDEC JESD22-A114 standard

( Human Body Mode ± 4kV), JEDEC JESD22-A115。

( machine

mode ± 200V) . If the test conditions exceed the

nominal limit , the sensor requires an additional

protection circuit.

1

AHT10

ADR

SDA

SCL

NC

GND

VDD

VDD 1.8~3.6V

VDD 1.8~3.6V

0.1 uf

MCU

(Master )

SDA

SCL

RP

RP