SARA-R4 series - System Integration Manual
UBX-16029218 - R06
System description
Page 11 of 102
Function
Pin Name
Pin No
I/O
Description
Remarks
UART
RXD
13
O
UART data output
1.8 V output, Circuit 104 (RXD) in ITU-T V.24,
for AT commands, data communication, FOAT.
See section 1.9.1 for functional description.
See section 2.6.1 for external circuit design-in.
TXD
12
I
UART data input
1.8 V input, Circuit 103 (TXD) in ITU-T V.24,
for AT commands, data communication, FOAT.
Internal active pull-up to
V_INT
.
See section 1.9.1 for functional description.
See section 2.6.1 for external circuit design-in.
CTS
11
O
UART clear to send
output
1.8 V output, Circuit 106 (CTS) in ITU-T V.24.
Not supported by “00”, “01” and “02” product versions.
See section 1.9.1 for functional description.
See section 2.6.1 for external circuit design-in.
RTS
10
I
UART ready to send
input
1.8 V input, Circuit 105 (RTS) in ITU-T V.24.
Internal active pull-up to
V_INT
.
Not supported by “00”, “01” and “02” product versions.
See section 1.9.1 for functional description.
See section 2.6.1 for external circuit design-in.
DSR
6
O
UART data set ready
output
1.8 V, Circuit 107 in ITU-T V.24.
See section 1.9.1 for functional description.
See section 2.6.1 for external circuit design-in.
RI
7
O
UART ring indicator
output
1.8 V, Circuit 125 in ITU-T V.24.
See section 1.9.1 for functional description.
See section 2.6.1 for external circuit design-in.
DTR
9
I
UART data terminal
ready input
1.8 V, Circuit 108/2 in ITU-T V.24.
Internal active pull-up to
V_INT
.
See section 1.9.1 for functional description.
See section 2.6.1 for external circuit design-in.
DCD
8
O
UART data carrier
detect output
1.8 V, Circuit 109 in ITU-T V.24.
See section 1.9.1 for functional description.
See section 2.6.1 for external circuit design-in.
USB
VUSB_DET
17
I
USB detect input
VBUS (5 V typical) USB supply generated by the host must
be connected to this input pin to enable the USB interface.
Test-Point for diagnostic / FW update access is recommended
See section 1.9.2 for functional description.
See section 2.6.2 for external circuit design-in.
USB_D-
28
I/O
USB Data Line D-
USB interface for AT commands, data communication,
FOAT, FW update by u-blox dedicated tool and diagnostic.
90
nominal differential impedance (Z
0
)
30
nominal common mode impedance (Z
CM
)
Pull-up or pull-down resistors and external series resistors as
required by the
USB 2.0 specifications
[4] are part of the
USB pin driver and need not be provided externally.
Test-Point for diagnostic / FW update access is recommended.
See section 1.9.2 for functional description.
See section 2.6.2 for external circuit design-in.
USB_D+
29
I/O
USB Data Line D+
USB interface for AT commands, data communication,
FOAT, FW update by u-blox dedicated tool and diagnostic.
90
nominal differential impedance (Z
0
)
30
nominal common mode impedance (Z
CM
)
Pull-up or pull-down resistors and external series resistors as
required by the
USB 2.0 specifications
[4] are part of the
USB pin driver and need not be provided externally.
Test-Point for diagnostic / FW update access is recommended.
See section 1.9.2 for functional description.
See section 2.6.2 for external circuit design-in.
