HDC2080 Digital Sensor : Circuit Diagram and Its Specifications

The HDC2080 is an integrated humidity and temperature sensor that provides high accuracy measurements while consuming very little power in a small DFN package. The capacitive-based sensor incorporates new digital features as well as a heating element to dissipate condensation and moisture.
The digital features of the HDC2080 include programmable interrupt thresholds for providing alerts and system wake-ups without the need for a microcontroller to continuously monitor the system.
The HDC2080 is intended for battery-powered systems due to its programmable sampling intervals, low power consumption, and support for a 1.8-V supply voltage.
A smaller CSP package option is available through the HDC2010 with complete software compatibility with the HDC2080 for designs where the printed-circuit board (PCB) area is critical.
Auto Measurement Mode allows the HDC2080 to automatically initiate temperature and humidity measurements in applications with strict power budgets.
Because the HDC2080 is no longer dependent on the microcontroller to initiate a measurement, this feature allows users to configure a microcontroller into deep sleep mode.

Block Diagram

The HDC2080 has two measurement modes: Auto and Trigger on-demand. In auto mode, the HDC2080 does not require any I2C commands to begin measuring. The IC is programmed to perform measurements regularly while in this mode.
I2C commands are required to initiate measurements in trigger on-demand mode. After the conversion is complete, the device enters sleep mode and waits for another I2C command to begin measuring.
The HDC2080 has two modes of operation: sleep and measurement. The key feature of HDC2080 that makes it suitable for energy harvesting applications is its low power consumption. When used for these types of applications, the HDC2080 spends the majority of its time in sleep mode. The average power consumption of the IC in this mode is 50 nA.
When working in a high humidity environment, the HDC2080 may experience condensation. To prevent this, the IC has an integrated heating element. This heater, which has an operating temperature range of -40°C to 85°C, can be turned on briefly to remove condensation.
On the I2C bus interface, the HDC2080 acts as a slave. To connect to the I2C interface, SDA and SCL open-drain lines are used. The HDC2080 also includes an ADC for converting analog to digital measurement values.

The accuracy of measuring RH and temperature values is greatly influenced by the proper setup of the sensing element and sensor accuracy. To improve sensor accuracy, isolate the HDC2080 from heat sources such as batteries, displays, resistive elements, and so on.
Prolonged exposure to UV radiation, chemical vapors, and visible light can affect the sensor’s RH percentage.

The HDC2080 is available in a 6-pin DMB 3.00mm 3.0mm package.
Pin-1 is the serial data line for I2C, also known as the SDA pin. This pin is connected to the positive supply voltage via a pull-up resistor.
GND, Pin-2, is the ground pin.
The address selected pin is Pin-3, ADDR. This pin can be left disconnected or hardwired to the ground. The slave address is 1000000 when unconnected or connected to the ground. The slave address is 1000001 when connected to a positive power supply.
The data ready/interrupt pin, DRDY/INT, is located on Pin 4.
Pin-5, VDD, represents the positive supply voltage.
The serial clock line for I2C is PIn-6, SCL. From this pin to the positive power supply, a pull-up resistor should be connected.

This sensor detects relative humidity.
It includes a capacitive sensing element.
This sensor’s relative humidity range is 0 to 100 percent.
The HDC2080’s typical humidity accuracy is 2°C.
The maximum temperature accuracy of this sensor is 0.2°C.
The HDC2080 has an operating temperature range of -40°C to 85°C.
This sensor’s operational temperature range is -40°C to 125°C.
The average supply current is 300nA when only RH percent is calculated, but 550nA when both RH percent and temperature are calculated.
This sensor includes an auto-measurement mode.
The HDC2080 sensor supports the I2C interface.
This IC’s supply voltage range is 1.62V to 3.6V.
The maximum input voltage required for this sensor to function properly is 3.9V.
This integrated circuit is available in a small DMB package.
A heating element is also embedded in the IC to dissipate condensation and moisture.
This IC also has programmable interrupt thresholds to provide alerts.
The sensor can be activated without the assistance of a microcontroller.
The HDC2010 is a smaller version of the HDC2080 that is available for applications where the PCB size is very small.
This IC has a very low power consumption requirement.
The HDC2080 has a 14-bit resolution when measuring RH or temperature.
The measurement of relative humidity takes 8 seconds.