SARA-G450 - System integration manual 
UBX-18046432 - R08  System description  Page 10 of 143 
C1-Public     
VSIM = 1.8 V (typical) or 2.8 V (typical) automatically 
generated according to the connected SIM type. 
See section 1.8 for functional description. 
See section 2.5 for external circuit design-in. 
Internal 4.7 k pull-up to VSIM. 
See section 1.8 for functional description. 
See section 2.5 for external circuit design-in. 
3.25 MHz clock output for 1.8 V / 3 V SIM. 
See section 1.8 for functional description. 
See section 2.5 for external circuit design-in. 
Reset output for 1.8 V / 3 V SIM. 
See section 1.8 for functional description. 
See section 2.5 for external circuit design-in. 
SIM presence detection function. 
See section 1.8.2 for functional description. 
See section 2.5 for external circuit design-in. 
Circuit 104 (RxD) in ITU-T V.24, for AT command, data, 
Mux, and FOAT. 
It operates at V_INT voltage level. 
See section 1.9.1 for functional description. 
See section 2.6.1 for external circuit design-in. 
Circuit 103 (TxD) in ITU-T V.24, for AT command, data, 
Mux, and FOAT. 
It operates at V_INT voltage level. 
See section 1.9.1 for functional description. 
See section 2.6.1 for external circuit design-in. 
UART clear to send 
output 
Circuit 106 (CTS) in ITU-T V.24. 
It operates at V_INT voltage level. 
See section 1.9.1 for functional description. 
See section 2.6.1 for external circuit design-in. 
UART request to 
send input 
Circuit 105 (RTS) in ITU-T V.24. 
It operates at V_INT voltage level. 
See section 1.9.1 for functional description. 
See section 2.6.1 for external circuit design-in. 
UART data set 
ready output 
Circuit 107 (DSR) in ITU-T V.24. 
It operates at V_INT voltage level. 
See section 1.9.1 for functional description. 
See section 2.6.1 for external circuit design-in. 
UART data 
terminal ready 
input 
Circuit 108/2 (DTR) in ITU-T V.24. 
It operates at V_INT voltage level. 
See section 1.9.1 for functional description. 
See section 2.6.1 for external circuit design-in. 
UART ring 
indicator output 
Circuit 125 (RI) in ITU-T V.24. 
It operates at V_INT voltage level. 
See section 1.9.1 for functional description. 
See section 2.6.1 for external circuit design-in. 
UART data carrier 
detect output 
Circuit 109 (DCD) in ITU-T V.24. 
It operates at V_INT voltage level. 
See section 1.9.1 for functional description. 
See section 2.6.1 for external circuit design-in.