AHT20

Part: AHT20 — Aosong

Type: Digital Temperature and Humidity Sensor

Description: Fully calibrated digital temperature and humidity sensor with I²C output, 2.0–5.5 V supply, in a 3 × 3 × 1.0 mm DFN-style SMD package.

Operating Conditions:

• Supply voltage: 2.0–5.5 V (3.3 V recommended)
• I²C slave address: 0x38
• Power-on time to idle state: 20 ms max; wait 40 ms after power-on before reading
• Recommended measurement interval: every 2 s, to keep self-heating below 0.1 °C

Absolute Maximum Ratings:

• ESD (HBM, JESD22-A114): ±4 kV
• ESD (machine model, JESD22-A115): ±200 V
• Maximum reflow soldering temperature: 260 °C (contact time under 30 s)

Key Specs:

• Interface: I²C, 7-bit address 0x38, no minimum SCL frequency
• Measurement time: about 80 ms wait after the 0xAC trigger command
• Soft reset time: 20 ms max
• Humidity resolution: 20-bit, RH [%] = SRH/2²⁰ × 100
• Temperature resolution: 20-bit, T [°C] = ST/2²⁰ × 200 − 50
• Moisture sensitivity level: MSL 1
• Recommended storage: 10–50 °C, 20–60 % RH
• 100 nF decoupling capacitor required between VDD and GND

Features:

• Fully calibrated
• Digital output, I²C interface
• Excellent long-term stability
• SMD package suitable for reflow soldering
• Quick response and strong anti-jamming capability
• New ASIC with MEMS capacitive humidity sensing element and on-chip temperature sensor
• CRC8 check data available

Applications:

• Temperature and humidity measurement in equipment and enclosures

Package:

• Double row flat no-lead SMD package, 3 × 3 mm footprint, 1.0 mm height

The electric specifcations of AHT20 are defned in Table 2. The absolute maximum ratings given in Table 6 are only stress ratings and to provide more information. Under such conditions, it is not advisable for the device to perform functional operation. Exposure to absolute maximum rating or a long time may affect the reliability of the sensor.

ESD electrostatic discharge conforms to JEDEC JESD22-A114 standard (human body mode ±4kV) and JEDEC JESD22-A115 (machine mode±200V) If the test condition exceeds the nominal limit, the sensor needs additional protection circuit.