Error! No text of specified style in document. - System Integration Manual
CDMA-2X-11004-P1
Objective Specification
Design-In
Page 53 of 79
50
Design-In
50.1
Design-in checklist
50.1.1
Schematic checklist
The following are the most important points for a simple schematic check:
DC supply must provide a nominal voltage at VCC pin above the minimum operating range
limit.
DC supply must be capable of supporting 1.2 A, providing a voltage at VCC pin above the
minimum operating range limit and with a maximum 250 mV voltage drop from the nominal
value.
VCC supply should be clean, with very low ripple/noise: suggested passive filtering parts can
be inserted.
Connect only one DC supply to VCC: different DC supply systems are mutually exclusive.
Don’t apply loads which might exceed the limit for maximum available current from V_INT
supply.
Check that voltage level of any connected pin does not exceed the relative operating
range.
Capacitance and series resistance must be limited on each SIM signal to match the SIM
specifications.
Insert the suggested low capacitance ESD protection and passive filtering parts on each
SIM signal.
Check UART signals direction, since the signal names follow the ITU-T V.24 Recommendation
[4].
Provide appropriate access to USB interface and/or to UART RxD, TxD lines and access to
PWR_ON and/or HW_SHUTDOWN lines on the application board in order to flash/upgrade
the module firmware.
Provide appropriate access to USB interface and/or to UART RxD, TxD, CTS, RTS lines for
debugging.
Add a proper pull-up resistor to a proper supply on each DDC (I
2
C) interface line, if the
interface is used.
Capacitance and series resistance must be limited on each line of the DDC interface.
Use transistors with at least an integrated resistor in the base pin or otherwise put a 10 k
Ω
resistor on the board in series to the GPIO when those are used to drive LEDs.
Insert the suggested passive filtering parts on each used analog audio line.
Provide proper precautions for ESD immunity as required on the application board.
All unused pins can be left floating on the application board Layout checklist
The following are the most important points for a simple layout check:
Check 50
nominal characteristic impedance of the RF transmission line connected to ANT
coax connector or Printed Circuit Board 50 transmission line impedance for LISA-C200
Follow the recommendations of the antenna producer for correct antenna installation and
deployment.
Ensure no coupling occurs with other noisy or sensitive signals (primarily SIM signals).
VCC line should be wide and short.
Ensure proper grounding.
