Safety Instructions

Proper Handling of the Power Supply

The YUKI Module A1 is designed for operation with a fixed supply voltage (typically 3.3 V, see datasheet for exact specifications). Exceeding the specified voltage ranges can lead to permanent damage to the module. Likewise, undervoltage must be avoided, as it can cause unstable behavior or system crashes.

Important notes:

• Check the power source before connecting (multimeter recommended).
• The supply voltage should be stable and clean (ripple < 50 mV).
• When using switching regulators, their output must be decoupled with sufficient capacitance.

DANGER

A voltage increase above 3.6 V (e.g. due to misconfiguration of GPIOs) can cause internal destruction.

Do Not Connect/Disconnect Antenna Connectors During Operation

The module has external antenna connectors (including for LTE-M and GNSS) that are connected via U.FL connectors. These may only be plugged or unplugged when the device is de-energized.

DANGER

Disconnecting during operation can damage the RF outputs, especially if the radio module is currently transmitting. In addition, it may lead to unexpected behavior in the firmware if, for example, GNSS data are lost or the modem can no longer establish a connection.

LTE/GNSS Radio Operation Only With Compliant Antenna

For reliable operation of the radio module, suitable antennas must be used that:

• are tuned for the frequency bands used (LTE-M, GNSS)
• are positioned correctly (e.g. GNSS with clear view of the sky)
• are connected via a sufficiently short and low-loss coaxial cable

Using unsuitable antennas can lead to reduced reception, dropped connections, or overheating. In extreme cases (mismatched antenna), the power amplifier may also be damaged.

WARNING

Use only antenna models approved by the manufacturer or observe the technical specifications (e.g. VSWR, bandwidth, impedance).

ESD Protection During Installation

WARNING

The module contains sensitive components that can be damaged by electrostatic discharge (ESD). Even handling without grounding can transfer potentially destructive voltages to pins or traces.

Protective measures:

• Wear an ESD wrist strap and use a grounded work surface
• Touch the module preferably only at the edges or connectors
• Mount antennas only with grounded tools
• A single ESD event can also cause latent defects that only become apparent later during operation.

EMC and Conformity Notes

The YUKI Module A1 is a radio device and can therefore cause electromagnetic interference or be affected by it. When integrating it into an end product, it must be ensured that the overall arrangement complies with the applicable regulations (e.g. RED, CE, FCC).

Notes on EMC-compliant integration:

• Route RF lines short and shielded
• Optimize ground routing (star topology, low impedance)
• Do not place the module too close to high-frequency interference sources (e.g. switching regulators)
• Observe enclosure grounding

Depending on the device category, renewed conformity testing may be required. Please observe the country-specific regulations and the notes in the datasheet and manufacturer documentation.