WM_PRJ_Q2501_PTS_002
- 001
March
2004
confidential ©
Page:
33 / 79
This document is the sole and exclusive property of WAVECOM. Not to be distributed or divulged
without prior written agreement.
Ce document est la propriété exclusive de WAVECOM. Il ne peut être communiqué ou divulgué à
des tiers sans son autorisation préalable.
3.3.4.2
SIM 1.8 V / 3 V management
It is possible to manage 1.8 V and 3 V SIM cards using an external level shifter
device (see Figure below).
In this case, depending on the type of SIM detected, the module firmware
triggers the GPO1 output signal (pin #42) in order to properly set the external
SIM driver level (1.8 V or 3 V).
As for 3 V SIM, it is recommended to add Transient Voltage Suppressors on
the signals connected to the SIM socket (refer to Figure 16).
Typical implementation:
CIN
RIN
DATA
DDRV
DVCC
M2
M1
M0
CLK
RST
I/O
VCC
VIN
C1+
C1-
GND
LTC1555L-1.8
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
VCC
2.8 V
WISMO
Q2501
SIM_CLK
SIM_RST
SIM_DATA
GPO1
SIM_VCC
SIM
Socket
VCC
2.8 V
2.2 µF
100 nF
LEVEL SHIFTER
3
CLK
2
RST
7
I/O
1
VCC = 1.8 V or 3 V
IVCC = 10 mA
6 VPP
VCC
4 CC4
8 CC8
1 µF
SIM_PRES
5
GND
470 pF
100 k
Ω
VCC
1
Ω
to
4.7
Ω
DVCC = 2.8 V
Operating Mode
Truth table:
M0
0V
0V
DVCC
DVCC
DVCC
M1
0V
0V
0V
DVCC
DVCC
M2
DVCC
0V
0V or DVCC
0V or DVCC
0V or DVCC
Shutdown (VCC = 0V)
VCC = VIN
VCC = 3 V
VCC = 1.8 V
VCC = 5 V
Figure 17: Example of 1.8 V / 3 V SIM interface implementation
Summary of Contents for WISMO Quik Q2501
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