HDC2080 Digital Humidity & Temperature Sensor: Circuit Diagram, Specs & Applications

The HDC2080 is a compact 6‑pin, 3 mm × 3 mm digital humidity and temperature sensor from Texas Instruments. It combines a capacitive humidity element, an accurate temperature sensor, a 14‑bit ADC, calibrated non‑volatile memory, and an I²C interface—all on a single die, making it ideal for battery‑powered and space‑constrained applications.

What Is the HDC2080?

Designed for low‑power operation, the HDC2080 delivers high‑resolution measurements (14 bits) for both relative humidity (RH) and temperature. Its operating temperature range is –40 °C to 85 °C (functional up to 125 °C), and it runs on 1.62 V–3.6 V supply. The integrated heater protects against condensation in high‑humidity environments.

Block Diagram

Operating Modes

The sensor supports two measurement modes:

• Auto‑mode: Measurements are taken automatically at a programmable interval without I²C commands.
• Trigger‑on‑Demand: Each measurement is initiated by an I²C command; after conversion the device enters sleep mode.

In sleep mode the average current consumption drops to 50 nA, which is ideal for energy‑harvesting and battery‑operated systems.

Heater and Condensation Prevention

To mitigate condensation when operating in humid environments, the HDC2080 includes an on‑chip heater that can be powered briefly. The heater is functional over the full temperature range of –40 °C to 85 °C.

Pin Configuration

• Pin 1 – SDA: I²C data line (open‑drain). Pull‑up to VDD.
• Pin 2 – GND: Ground.
• Pin 3 – ADDR: Address pin. Leave unconnected or tie to GND for 0x40; tie to VDD for 0x41.
• Pin 4 – DRDY/INT: Data‑ready/interrupt output.
• Pin 5 – VDD: Supply voltage (1.62 V–3.6 V).
• Pin 6 – SCL: I²C clock line (open‑drain). Pull‑up to VDD.

Key Specifications

• RH measurement range: 0 %–100 % RH
• RH accuracy: ± 2 %
• Temperature accuracy: ± 0.2 °C
• Resolution: 14 bits for both RH and temperature
• Response time (RH): 8 s
• Average current (RH only): 300 nA
• Average current (RH + Temp): 550 nA
• Auto‑measurement mode: supported
• I²C interface: compatible
• Supply voltage: 1.62 V–3.6 V (max input 3.9 V)
• Package: 3 mm × 3 mm DMB
• Integrated heater for condensation
• Programmable interrupt thresholds
• Wake‑up capability without microcontroller assistance

Typical Applications

The HDC2080’s low power, small footprint, and digital output make it suitable for:

• Home appliances (washers, dryers)
• HVAC control systems
• Medical equipment (hospital rooms, patient monitoring)
• Inkjet printers and other precision devices
• Battery‑powered sensors and wearables

Alternative Devices

Other Texas Instruments models with similar capabilities include the HDC1010, HDC1080, and the smaller HDC2010. Choose based on size, resolution, and power requirements.

For detailed electrical data and storage recommendations, consult the Texas Instruments datasheet.

Image Credit: Texas Instrumentation