The LTE modem provides dedicated 1.8 V digital interfaces for controlling external RF applications, such as antenna tuner devices.
The LTE modem supports the following pins:
- MIPI RFFE interface pins – VIO, SCLK, SDATA
- MAGPIO interface pins – MAGPIO0, MAGPIO1, MAGPIO2
The LTE modem accurately drives the timing of these outputs according to the LTE protocol, to set the correct antenna tuner settings per used frequency, for example. The LTE modem API must be used to inform the LTE modem about the external RF application, so that LTE modem knows to drive it.
Note: For details regarding the modem API and supported RF external control features, see nRF91 AT Commands.
Note: The MIPI RFFE capacitive load at SCLK or SDATA pins must not exceed 15 pF.
The MIPI RFFE interface timing in relation to modem state is shown in the following figure.
Figure 1. MIPI RFFE interface timing
The MAGPIO interface timing in relation to the LTE modem state is shown in the following figure.
Figure 2. MAGPIO interface timing
