LISA-U2 series - System integration manual
UBX-13001118 - R27
Design-In
Page 127 of 183
C1-Public
typically accessed by the end user, it can be subjected to ESD discharges: add adequate ESD
protection to protect module SIM pins near the SIM connector
•
Digital Audio (I2S_CLK
,
I2S_RX
,
I2S_TX
,
I2S_WA
and
I2S1_CLK
,
I2S1_RXD
,
I2S1_TXD
,
I2S1_WA)
:
the I2S interface requires the same consideration regarding electro-magnetic interference as the
SIM card. Keep the traces short and avoid coupling with RF line or sensitive analog inputs
•
DDC (SCL, SDA)
: the DDC interface requires the same consideration regarding electro-magnetic
interference as the SIM card. Keep the traces short and avoid coupling with RF line or sensitive
analog inputs
•
UART (TXD, RXD, CTS, RTS, DSR, RI, DCD, DTR)
: the serial interface requires the same
consideration regarding electro-magnetic interference as the SIM card. Keep the traces short and
avoid coupling with RF line or sensitive analog inputs
•
General Purpose I/O (GPIOx)
: the general purpose input/output pins are generally not critical for
layout
•
Reserved pins
: these pins are reserved for future use. Leave them unconnected on the baseboard
•
USB detection
(VUSB_DET)
: this input will generate an interrupt to the baseband processor for
USB detection. The USB supply (5.0 V typ.) must be provided to
VUSB_DET
by the connected USB
host to enable the USB interface of the module
•
Interfaces Supply
(V_INT)
: this supply output is generated by an integrated switching step down
converter, used internally to supply the digital interfaces. Because of this, it can be a source of
noise: avoid coupling with sensitive signals