Chapter 5 – Test Board
Wireless ModemModule MTMMC-G-F1 and MTMMC-G-F2 Developer’s Guide
36
SIM Schematic (5V)
SIM Schematic
GND
VIN = 5V
GND
LTC1555 SIM 3V/5V Level shifter.
GND
VCC = 2.8V
GND
R12
100K
R22
0
U6
LTC1555
8
12
5
6
7
11
10
9
16
1
13
2
15
14
4
3
M0
V IN
DV CC
SS
M1
C1+
C1-
GND
CLK
CIN
V CC
RIN
RST
I/O
DDRV
DA TA
Place C30
near pin
13 of U6.
GND
C17
2.2uF
SIMCLK
R21
0
C_GPO0
C43
2.2uF
R13
100K
V CC
VIN
GND
GND
C28
.1uF
R20, R21, R22 and R23
are used to shunt
LTC1555.
SIM interface from
Modem Module.
+
C30
33uF
R20
0
SIMV CC
R23
0
SIMPRES1
GND
4.7K
10K
47K
47K
U4
UMC5NT1
1
4
5
3
2
SIMDA TA
J2
SIM_6P
1
2
3
4
5
6
7
8
VCC
RST
CLK
CC4
GND
VPP
I/0
CC8
R15
1K
GND
SIMRST
R14
100K