WM_PRJ_Q2400_PTS_005 -007
18th January 2006
Confidential©
All rights reserved
Page:
20
/
51
This document is the sole and exclusive property of WAVECOM. Not to be
distributed or divulged without prior written agreement.
Typical serial resistors values (R) for signals between application and WISMO
Quik Q2400 (mainly CT103/TX) (see Figure 6).
Host output voltage
UART baud rate
<3.1V 3.2V
3.3V
9 600
R < 62 k
Ω
6.8
k
Ω
< R < 62 k
Ω
11
k
Ω
< R < 62 k
Ω
19 200
R < 30 k
Ω
6.8
k
Ω
< R < 30 k
Ω
11
k
Ω
< R < 30 k
Ω
38 400
R < 15 k
Ω
6.8
k
Ω
< R < 15 k
Ω
11
k
Ω
< R < 15 k
Ω
57 600
R < 10 k
Ω
6.8
k
Ω
< R < 10 k
Ω
Not supported
115 200
R < 5.1 k
Ω
Not supported
Not supported
The minimal value is determined to limit the current in the input pin of the
Module and the maximal value is determined by its input capacitance. That
explains why some combinations speed / voltage are incompatible.
2.2.6 SIM interface
2.2.6.1 SIM 3V management
The SIM interface controls a 3 V SIM card only.
Nevertheless, it is possible to manage 1.8V/3V or 3V/5V SIM cards using an
external voltage level shifter controlled by the GPO0 output signal (refer to §
2.2.6.2 and § 2.2.6.3).
It is recommended to add Transient Voltage Suppressor diodes (TVS) on the
signal connected to the SIM socket in order to prevent any Electrostatic
Discharge.
TVS diodes with low capacitance (less than 10 pF) have to be connected on
SIM_CLK and SIM_DATA signals to avoid any disturbance of the rising and
falling edge.
These types of diodes are mandatory for the Full Type Approval. They shall be
placed as close as possible to the SIM socket.
The following references can be used: DALC208SC6 from ST Microelectronics.
