Overview

Part: SHTC3 from Sensirion

Type: Digital Humidity and Temperature Sensor IC

Key Specs:

Supply Voltage Range: 1.62 V to 3.6 V
Humidity Measurement Range: 0 to 100 %RH
Temperature Measurement Range: -40 °C to 125 °C
Typical Humidity Accuracy: ±2 %RH
Typical Temperature Accuracy: ±0.2 °C
Energy Budget per Measurement: <1 μJ
Measurement Time: within 1 ms

Features:

Ultra-low power consumption
Fully calibrated and reflow solderable
NIST traceability
I²C Fast Mode Plus digital communication interface
CMOSens® technology (complete sensor system on a single chip)
High reliability and long-term stability
Designed for mass production
Unique serial number

Applications:

Battery-driven high-volume consumer electronics
Mobile or wireless applications
High-volume applications

Package:

DFN: 2 × 2 × 0.75 mm³

Electrical Characteristics

2.1 Electrical Characteristics

Default conditions of 25 °C and 3.3 V supply voltage apply to values in the table below, unless otherwise stated.

Parameter	Symbol	Conditions	Min	Typ.	Max	Units	Comments
Supply voltage	VDD		1.62	3.3	3.6	V	-
Power-up/down level	VPOR	Static power supply	1.28	1.4	1.55	V	-
Supply current	IDD	Idle state	-	45	70	μA	After power-up the sensor remains in the idle state unless a sleep command is issued or other data transmission is active
Supply current	IDD	Sleep Mode	-	0.3	0.6	μA	When in sleep mode, the sensor requires a dedicated wake-up command to enable further I2C communication
Supply current	IDD	Measurement Normal Mode	-	430	900	μA	Average current consumption while the sensor is measuring
Supply current	IDD	Measurement Low Power M.	-	270	570	μA	Average current consumption while the sensor is measuring
Supply current	IDD	Average Normal Mode	-	4.9	-	μA	Average current consumption (continuous operation with one measurement per second)
Supply current	IDD	Average Low Power M.	-	0.5	-	μA	Average current consumption (continuous operation with one measurement per second)
Low level input voltage	VIL	-	-	-	0.42 VDD	V	-
High level input voltage	VIH	0.7 VDD	-	-	-	V	-
Low level output voltage	VOL	3 mA sink current	-	-	0.2 VDD	V	-

Figure 4 Typical accuracy of relative humidity measurements given in %RH for temperatures 0°C … 80°C.

1.2 Recommended Operating Conditions

The sensor performs best when operated within the recommended normal temperature and humidity range of 5 – 60 °C and 20 – 80 %RH, respectively. Long-term exposure to conditions outside the normal range, especially at high humidity, may temporarily offset the RH signal (e.g. +3%RH after 60h at >80%RH). After returning to normal temperature and humidity range the sensor will slowly come back to its calibration state by itself. Prolonged exposure to extreme conditions may accelerate ageing.

To ensure stable operation of the humidity sensor, please refer to the Handling Instructions SHT. Please note as well that this does apply not only to transportation and manufacturing, but also to operation of the SHTC3.

2.2 Absolute Maximum Ratings

Stress levels beyond the limits listed in Table 4 may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these conditions cannot be guaranteed. Exposure to the absolute maximum rating conditions for extended periods may affect the reliability of the device. Parameters are only tested each at a time.

Parameter	Rating
Supply voltage, VDD	-0.3 to +4 V
Operating temperature range	-40 to +125 °C
Storage temperature range¹⁰	-40 to +125 °C
ESD HBM (human body model)¹¹	-2 to 2 kV
ESD CDM (charge device model)¹²	-500 to 500 V
Latch up, JESD78 Class II, 125°C	-100 to 100 mA

3 Timing Specifications

3.1 Sensor System Timings

Default conditions of 25 °C and 3.3 V supply voltage apply to values the table below, unless otherwise stated. Max. values are measured at -40 °C.

Parameter	Symbol	Conditions	Min.	Typ.	Max.	Units	Comments
Power-up time	tPU	After hard reset, VDD ≥ VPOR	-	180	240	μs	Time between VDD reaching VPU and sensor entering the idle state
Soft reset time	tSR	After soft reset	-	180	240	μs	Time between ACK of soft reset command and sensor entering the idle state
Measurement duration	tMEAS	Average Normal Mode	-	10.8	12.1	ms	Duration for a humidity and temperature measurement
		Average Low Power M.	-	0.7	0.8

¹⁰ The recommended storage temperature range is 10-50°C. Please consult the document "SHTxx Handling Instructions" for more information.

¹¹ According to ANSI/ESDA/JEDEC JS-001-2014; AEC-Q100-002.

¹² According to ANSI/ESD S5.3.1-2009; AEC-Q100-011.

3.2 Communication Timings

Default conditions of 25 °C and 3.3 V supply voltage apply to values in the table below, unless otherwise stated.

| Parameter | Symbol | Conditions | Standard-mode | Fast-mode | Fast-mode Plus | Units | |---|---|---|---|---|---|---|---|---|---| | | | | Min. | Max. | Min. | Max. | Min. | Max. | | | SCL clock frequency | fSCL | - | 0 | 100 | 0 | 400 | 0 | 1000 | kHz | | Hold time (repeated) START condition | tHD;STA | After this period, the first clock pulse is generated | 4.0 | - | 0.6 | - | 0.26 | - | μs | | LOW period of the SCL clock | tLOW | - | 4.7 | - | 1.3 | - | 0.5 | - | μs | | HIGH period of the SCL clock | tHIGH | - | 4.0 | - | 0.6 | - | 0.26 | - | μs | | Set-up time for a repeated START condition | tSU;STA | - | 4.7 | - | 0.6 | - | 0.26 | - | μs | | SDA hold time | tHD;DAT | - | 0 | - | 0 | - | 0 | - | μs | | SDA set-up time | tSU;DAT | - | 250 | - | 100 | - | 50 | - | ns | | SCL/SDA rise time | tR | - | | 1000 | 20 | 300 | | 120 | ns | | SCL/SDA fall time | tF | - | | 300 | 20 x (VDD / 5.5V) | 300 | 20 x (VDD / 5.5V) | 120 | ns | | SDA valid time | tVD;DAT | - | | 3.45 | | 0.9 | | 0.45 | μs | | Set-up time for STOP condition | tSU;STO | - | 4.0 | - | 0.6 | - | 0.26 | - | μs | | Capacitive load on bus line | CB | - | | 400 | | 400 | | 550 | pF |

Table 6 Communication timing specifications. The numbers above are values according to the I2C specification.

Figure 5 Timing diagram for digital input/output pads. SDA directions as seen from the sensor. Bold SDA lines are controlled by the sensor, plain SDA lines are controlled by the micro-controller. Note that SDA valid read time is triggered by falling edge of preceding toggle.

Absolute Maximum Ratings

Stress levels beyond the limits listed in Table 4 may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these conditions cannot be guaranteed. Exposure to the absolute maximum rating conditions for extended periods may affect the reliability of the device. Parameters are only tested each at a time.

Parameter	Rating
Supply voltage, VDD	-0.3 to +4 V
Operating temperature range	-40 to +125 °C
Storage temperature range¹⁰	-40 to +125 °C
ESD HBM (human body model)¹¹	-2 to 2 kV
ESD CDM (charge device model)¹²	-500 to 500 V
Latch up, JESD78 Class II, 125°C	-100 to 100 mA

Recommended Operating Conditions

The sensor performs best when operated within the recommended normal temperature and humidity range of 5 – 60 °C and 20 – 80 %RH, respectively. Long-term exposure to conditions outside the normal range, especially at high humidity, may temporarily offset the RH signal (e.g. +3%RH after 60h at >80%RH). After returning to normal temperature and humidity range the sensor will slowly come back to its calibration state by itself. Prolonged exposure to extreme conditions may accelerate ageing.

To ensure stable operation of the humidity sensor, please refer to the Handling Instructions SHT. Please note as well that this does apply not only to transportation and manufacturing, but also to operation of the SHTC3.