Smart Machine Smart Decision
SIM5800_Hardware Design_V1.01
31
2018-10-08
VIO18_PMU
4.7K
47K
4.7K
Customer
RXD
Module
VIO18_PMU
TXD
VDD
Figure 22: RX level converting by transistor
Note: When using the level isolation in Figure 21 and Figure 22, please pay attention to the output
sequential of VIO18_PMU. Only after VIO18_PMU is normally output, can the serial port communicate
normally.
4.8
SD card
Table 8: SD interface
Refer to the following application circuit:
1 DAT2
2 DAT3
3 CMD
4 VDD
5 CLK
6 VSS
7 DAT0
8 DAT1
11 GND
12 GND
13 GND
14 GND
9 DET_SW
10 COMMON
SD card
SD_DATA2
SD_DATA3
SD_CMD
VMCH_PMU
SD_CLK
SD_DATA0
SD_DATA1
NM
SD_DET
VIO18_PMU
Module
1uF
33pF
TVS
C<15pF
33R
N
M
N
M
N
M
N
M
N
M
1uF
VMC_PMU
Name
Pin
I/O
Description
VMC_PMU
32
O
Pull up
VMCH_PMU
38
O
Power supply
SD_CLK
39
O
SDIO clock
SD_CMD
40
I/O
SDIO command
SD_DATA0
41
I/O
SDIO data0
SD_DATA1
42
I/O
SDIO data1
SD_DATA2
43
I/O
SDIO data2
SD_DATA3
44
I/O
SDIO data3
SD_DET
45
I
SD card detection