This section describes the operating conditions that affect the performance and behavior of nRF9151.
Temperature range
The optimal operating case temperature (Tc) of nRF9151 ranges from –30°C to 65°C, achieving the best RF performance including output power transmission and receiver sensitivity.
The nRF9151 transceiver remains regulatory compliant for case temperatures that range from –40°C to 85°C. Case temperature is typically the main cause for degradation in RF performance and current consumption, but other factors, such as supply voltage and signaling parameters, can contribute as well.
Case temperature is affected by the ambient temperature combined with nRF9151's internal thermal dissipation originating from the transceiver and application processor's activity.
Thermal protection
nRF9151 has a built-in thermal protection mechanism to prevent the RF Power Amplifier (PA) from breaking and the Long-Term Evolution (LTE) modem from operating beyond the specified temperature range.
When the internal temperature sensor in nRF9151 measures a case temperature of 90°C, the LTE modem, DECT NR+ transceiver, and Global Navigation Satellite System (GNSS) are deactivated to minimize the internal heat generation and to protect the RF PA. The application can monitor case temperature using the %XTEMP AT command. When %XTEMP indicates that the case temperature has dropped below 90°C, the application can reactivate the LTE modem with the +CFUN AT command. Using the application processor is not limited by the thermal protection mechanism.
For more information on thermal protection, see Internal temperature notification %XTEMP in nRF91x1 Cellular AT Commands Reference Guide.
Voltage range
The operational voltage of nRF9151 can be found in nRF9151 Product Specification. The LTE and DECT NR+ transceiver requires a minimum voltage of 3.0 V to fulfill RF performance in the environmental conditions described in nRF9151 Product Specification. For optimal RF performance in LTE, a minimum operating voltage of 3.2 V is recommended.