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2.5 Temperature and Humidity Compensation

The STCC4 requires continuous input from an external SHT4x temperature and humidity sensor for accurate

compensation of the CO2 concentration output. The recommended application circuit for the STCC4 is shown

in Figure 1. The STCC4 has a dedicated I2C controller interface for connecting to SHT4x sensors with

I2C address 0x44. The STCC4 I2C controller interface pads SDA_C and SCL_C have internal pull-up resistors of

10 kΩ. Additional pull-up resistors between the STCC4 and SHT4x are not recommended if the SHT4x is

designed close to the STCC4. The pull-up resistor values (Rp) must be dimensioned based on the bus capacity,

communication frequency and NXP I2C-bus specification and user manual11.

Figure 1. Recommended application circuit. The positioning of the pins is only for illustrative purposes.

2.6

Timing Specifications

Parameter

Sym.

Conditions

Min

Typ

Max

Unit

Power-up time

tPU

After hard reset, VDD ≥ 2.7 V

10

ms

I2C SCL frequency

fI2C

400

1’000

kHz

Table 6. Timing specifications

2.7

Mechanical Specifications

Parameter

Sym.

Conditions

Min

Typ

Max

Unit

Mass

m

0.02

g

Table 7. Mechanical specifications

2.8

Material Specifications

Parameter

Conditions

REACH, RoHS, Halogen-Free

Compliant

Table 8. Material specifications

11

NXP I2C-bus specification and user manual UM10204, Rev.7, 01 November 2021