SL871 Family Product User Guide
1VV0301170 Rev. 9
Page 47 of 89
2021-07-15
Not Subject to NDA
9.3.2.2.
ANT-ON (output)
Antenna on (ANT-ON) is an output logic signal to control the power supplied to an
external LNA or active antenna (e.g. using an external FET switch connected from VCC-
RF to a bias-T). When logic high, the external antenna or LNA should be active; when logic
low the external antenna should be powered down.
This signal is not available on the SL871 Gen 1.
The logic levels are shown in Table 27: Output Logic Levels: ANT_ON.
9.3.2.3.
ANT-OC (SL871 and SL871L only)
This signal is a high true input. When the input is at logic 1, the receiver will output a
special NMEA message indicating the antenna line is open. The circuitry to drive this input
is external to the SL871 module. This signal is only available on the SL871 and SL871L.
The logic levels are shown in Table 24: Input Logic Levels: RX and Reset-N, & Ant Sense.
Note that this pin can be configured to be Data Ready Indicator for I2C.
9.3.2.4.
ANT-SC-N (SL871 and SL871L only)
This signal is a low true input. When the input is at logic 0, the receiver will output a
special NMEA message indicating the antenna line is shorted. The circuitry to drive this
input is external to the SL871 module. This signal is only available on the SL871 and
SL871L.
The logic levels are shown in Table 24: Input Logic Levels: RX and Reset-N, & Ant Sense.
Control (Input) Signals
9.3.3.1.
RESET-N
The Reset-N input is a low true input to reset the receiver to the default starting state.
Reset-N has an internal pullup.
This signal is not required for the module to operate properly, so this pin may be left
unconnected. However, it is recommended to bring it out to a test point.
The logic levels are shown in Table 24: Input Logic Levels: RX and Reset-N, & Ant Sense.
