HTU20D(F) RH/T SENSOR IC

Digital Relative Humidity sensor with Temperature output

9/2015

Page 8

No specific conditioning of devices is necessary after soldering process, either manual or reflow soldering.

Optimized performance in case of metrological measurements can be reached with stabilization of devices (24

hours at 25°C / 55%RH). Similar process is advised after exposure of the devices to extreme relative humidity

conditions.

In no case, neither after manual nor reflow soldering, a board wash shall be applied. Therefore, it is strongly

recommended to use a “no-clean” solder paste. In case of applications with exposure of the sensor to corrosive

gases or condensed water (i.e. environments with high relative humidity) the soldering pads shall be sealed (e.g.

conformal coating) to prevent loose contacts or short cuts.



Storage Conditions and Handling Instructions

It is recommended to store HTU20D(F) sensor in its original packaging at following conditions: Temperature shall

be in the range of -40°C

– 125°C.



Temperature Effects

Relative humidity reading strongly depends on temperature. Therefore, it is essential to

keep humidity sensors at the same temperature as the air of which the relative humidity

is to be measured.

In case of testing or qualification the reference sensor and test sensor must show equal

temperature to allow for comparing humidity readings.

The HTU20D(F) sensor should be mounted in a way that prevents heat transfer from

electronic sensor or that keeps it as low as possible. Advice can be ventilation, reduction

of copper layers between the HTU20D(F) sensor and the rest of the PCB or milling a

slit into the PCB around the sensor (1mm minimum width).

Example of HTU20D(F) sensor mounting

with slits mills to minimize heat transfer



Materials Used for Sealing / Mounting

For sealing and gluing (use sparingly), use high filled epoxy for electronic packaging and silicone. For any specific

material please request to humidity.application@te.com.

Window must remain uncovered.



Wiring Considerations and Signal Integrity

Carrying the SCK and DATA signal parallel and in close proximity (e.g. in wires) for more than 10 cm may result in

cross talk and loss of communication.

This may be resolved by routing VDD and/or GND between the two data signals and/or using shielded cables.

Furthermore, slowing down SCK frequency will possibly improve signal integrity.

Power supply pins (VDD, GND) must be bypassed with a 100nF capacitor if wires are used. Capacitor should be

placed as close as possible to the sensor.